Contact lens package integrity testing

Abstract

A method may include: introducing a contact lens blister pack into a sterilizer unit, wherein the contact lens blister pack includes a packaging base having a cavity, a contact lens disposed in the cavity, a packaging solution disposed in the cavity, and a material forming a seal above the cavity; controlling operating conditions of the sterilizer unit such that if a defect exists in the contact lens blister pack, at least a portion of the packaging solution is discharged from the contact lens blister pack; introducing the contact lens blister pack into a packaging integrity testing unit; and detecting whether the contact lens blister pack is defective based at least on the amount of remaining packaging solution.

Description

[0001] Related applications This application claims priority to U.S. Provisional Patent Application Serial No. 63 / 549,709, filed on February 5, 2024. Background Technology

[0002] Contact lens blister packaging is a relatively economical option for storing lenses before use by the wearer. Traditional blister packaging for disposable lenses includes a packaging base comprising a cavity surrounded by a flange. This cavity contains the contact lens and a packaging solution and is sealed along a sealing area by a removable cap, typically made of a film (e.g., a multilayer film comprising a sealing layer and a foil layer). The contact lens base is typically a thermoformed plastic material produced by injection molding of polyethylene, polypropylene, polyvinyl chloride, or polyethylene terephthalate. The contact lens base has high rigidity but is capable of limited plastic deflection and includes a pre-formed cavity. This cavity is filled with a suitable packaging solution, preferably a buffered saline solution, and a single lens is accommodated within the cavity. The cavity is then sealed and sterilized using steam and pressure (e.g., autoclaving).

[0003] The packaging base provides several important functions for the contact lens. It protects the lens during transport and maintains its hydration by keeping it submerged in the packaging solution. The packaging base can be designed to support the submerged lens, with either the convex surface of the lens facing the removable cap, or the concave (corneal contact) surface of the lens facing the removable cap. The packaging base also supports the lens to prevent it from folding or inverting during transport (which could lead to incorrect application and use of the lens).

[0004] Packaging integrity testing is a critical step in contact lens production. Contact lens packaging must be leak-proof to maintain sterility and lens hydration. Current packaging integrity testing methods require technicians to remove a representative number of sample packages from each batch manufactured. These samples are then subjected to dye entry testing, whereby the lens package is immersed in dye under vacuum. For defective contact lens packages, dye can be drawn into the defective package under vacuum and is therefore identifiable. If the packaging is deemed defective, the entire batch manufactured is discarded. While dye entry testing is effective in determining whether an individual package is defective, it cannot detect every defect in a manufacturing batch. For example, if a defective package is not among the representative samples, it may not be detected. Furthermore, dye entry testing is time-consuming and requires quality control operators to physically select and handle samples from each representative batch and insert them into the dye and vacuum chamber. During quality control testing, the manufacturing batch may be paused, increasing work-in-process (WIP) and delivery time for the batch. Summary of the Invention

[0005] This document discloses an example method comprising: introducing a contact lens blister pack into a sterilizer unit, wherein the contact lens blister pack includes a packaging base having a cavity, a contact lens disposed in the cavity, and a packaging solution, and forming a sealing film over the cavity; controlling operating conditions of the sterilizer unit such that if a defect exists in the contact lens blister pack, at least a portion of the packaging solution is discharged from the contact lens blister pack; and detecting whether the contact lens blister pack is defective based at least on the amount of remaining packaging solution.

[0006] This document also discloses another example method, which includes: introducing a contact lens blister pack into a sterilizer unit, wherein the contact lens blister pack includes a packaging base having a cavity, a contact lens disposed in the cavity, a packaging solution, and a sealing material forming above the cavity, wherein the contact lens blister pack includes a defect; controlling the operating conditions of the sterilizer unit such that at least a portion of the packaging solution is discharged from the contact lens blister pack through the defect; and introducing the contact lens blister pack into a packaging integrity testing unit and detecting the defect.

[0007] It should be understood that the above general description and the following detailed description are exemplary and illustrative, intended to provide an understanding of the present disclosure, and not to limit its scope. In this regard, additional aspects, features, and advantages of the present disclosure will be apparent to those skilled in the art from the following detailed description. Attached Figure Description

[0008] These figures illustrate certain aspects of embodiments of the invention and should not be construed as limiting or restricting the invention.

[0009] Figure 1 This is a schematic perspective view of a device for sterilizing and repackaging an interconnected blister pack array used to sterilize and contain contact lenses.

[0010] Figure 2 This is a phase diagram illustrating a disinfection cycle.

[0011] Figure 3 This is a phase diagram illustrating another disinfection cycle.

[0012] Figure 4a is a schematic diagram of a blister pack array.

[0013] Figure 4b is a side view of the blister pack array.

[0014] Figure 4c is a schematic diagram of two nested blister pack arrays with the seals facing outwards.

[0015] Figure 5A method for identifying defective blister packaging is illustrated.

[0016] Figure 6 A method for identifying defective blister packaging is illustrated.

[0017] Figure 7 A method for identifying defective blister packaging is illustrated.

[0018] Figure 8 Examples are provided for implementation. Figure 7 The apparatus for the method. Detailed Implementation

[0019] This article discloses a method for detecting defects in contact lens packaging, and more specifically, this article discloses a method for detecting defects in contact lens packaging by using a sterilization unit to drain a portion of the liquid inside the contact lens packaging and detecting the volume change of the liquid inside the contact lens packaging.

[0020] Examples of packaging integrity testing methods include using a sterilization unit to drain a portion of the liquid within the contact lens packaging and detecting changes in the volume of the liquid within the contact lens packaging. The example methods offer several advantages over previous methods for testing the integrity of contact lens packaging, some of which may only be mentioned herein. The example methods for packaging integrity testing allow for in-line testing of each contact lens package manufactured on the production line, thus ensuring the quality of each contact lens package released to the customer. The example methods also individually identify defective contact lens packages within a manufacturing batch, so that only those considered defective are disposed of, thus avoiding unnecessary disposal of the rest of the manufacturing batch. The example in-line packaging integrity testing methods also reduce ongoing work by eliminating the need to store the manufacturing batch while testing a representative sample of the batch. The example methods for packaging integrity testing also allow for the removal of several pieces of equipment and chemicals from the manufacturing process, as the methods of the present invention do not require vacuum equipment and dye solutions, which reduces the amount of waste stream associated with contact lens manufacturing. Furthermore, the example methods can be automated, thereby eliminating the need for operators to manually handle representative samples of contact lens packaging, thus reducing overhead costs associated with manufacturing contact lens packaging.

[0021] Contact lens manufacturing method Contact lenses can be formed by introducing a reactive mixture into a mold, where the mold defines the optical properties of the contact lens. The reactive mixture can be photo- and / or thermally cured to form the contact lens. After curing, the contact lens can be removed from the mold and subjected to various processing steps, such as hydration and extraction, and transferred to a packaging step, in which the contact lens can be deposited into a packaging base along with a packaging solution. The finished blister pack containing the contact lens can then be sterilized, such as in an autoclave, before final packaging into a carton.

[0022] In the first step of contact lens manufacturing, a reactive mixture can be formed into a contact lens by dispensing the mixture into a mold assembly and subsequently curing the mixture. The mold assembly may include a bottom curved surface and a front curved surface, the bottom curved surface being a mold half of the rear surface of the contact lens, and the front curved surface being a mold half of the rear surface of the contact lens. When joined together, the front and bottom curved surfaces can define and enclose a cavity between them that contains the reactive mixture.

[0023] The molded components of the mold assembly (front-curved mold and bottom-curved mold) can be made of a variety of materials, including disposable or reusable materials. For example, the mold may include a thermoplastic optical mold. The mold assembly can be made of any suitable material, including but not limited to polyethylene, polypropylene, polyolefins (including homopolymers, copolymers, and terpolymers), polystyrene, polystyrene copolymers, polyesters such as poly(ethylene terephthalate) and poly(butylene terephthalate), polyamide, poly(vinyl alcohol) and its derivatives, hydrogenated styrene-butadiene block copolymers, cyclic olefin polymers (COP) and copolymers (COC), and combinations thereof. COP plastic resins are commercially available from Zeon Chemicals (Zeonex and Zeonor resins) and Japan Synthetic Rubber (JSR). COC plastic resins are commercially available from Topas Advanced Polymers (Topas resins) and Mitsui (APEL resins). The mold may be selected to be transparent or nearly transparent to the wavelength of the activated photoinitiator, thereby allowing irradiation through the front and bottom curved surfaces. The materials in the front and bottom surfaces may be the same or different. Examples of materials for the front surface of the mold assembly may include COP (such as Zeonor 1060R) or COC (such as Topas 8007 or 5013), either pure or as blends, such as approximately 90:10 (w / w) blends of COC or COP with hydrogenated styrene-butadiene block copolymers, respectively. Examples of suitable materials for the bottom surface of the mold assembly may include the aforementioned COC, COP, polypropylene, blends thereof, and blends with hydrogenated styrene-butadiene block copolymers. Blends of approximately 90:10 (w / w) cyclic olefin polymers and polypropylene may also be used.

[0024] The activating radiation source for initiating a photoinitiator may include, but is not limited to, a lamp that transmits light at a suitable wavelength for such initiation. One method may include emitting activating radiation from a light-emitting diode (LED) lamp. An LED lamp that emits radiation at a desired intensity and in a wavelength range including from about 200 nanometers (nm) to about 600 nm may be used. Alternatively, from about 300 nm to about 500 nm, and most preferably from about 350 nm to about 450 nm.

[0025] The curing step can be achieved by exposing the reactive mixture to heat or radiation, or a combination thereof, including an activation wavelength (i.e., the wavelength required to activate the photoinitiator). The radiation can be directed to either or both of the bottom and front surfaces of the mold assembly. The radiation energy at the bottom surface may be greater than the radiation energy at the front surface.

[0026] The intensity of the radiation is typically around 0.1 mW / cm². 2 Approximately 25 mW / cm 2 Within that range. Alternatively, at approximately 1 mW / cm². 2 Approximately 10 mW / cm 2 Approximately 1mW / cm 2 Approximately 15 mW / cm 2 Approximately 15mW / cm 2 Approximately 25 mW / cm 2 , or any range thereof.

[0027] After curing, the lens can undergo further processing steps, such as hydration to cause swelling, extraction to remove unreacted components from the lens, and release of the lens from the lens mold. These steps can be performed in any order. Extraction can be performed using an extraction fluid, including but not limited to organic solvents, alcohols, aqueous solutions containing water, and mixtures thereof. Examples of aqueous solutions may include at least about 20% by weight of water, or at least about 50% by weight of water, or at least about 70% by weight of water, or at least about 95% by weight of water. Aqueous solutions may also include additional water-soluble compounds, such as inorganic salts or release agents, wetting agents, slip agents, pharmaceuticals and nutritional preparations, and combinations thereof. Release agents may contain compounds or mixtures of compounds that, when combined with water, reduce the time required to remove the contact lens from the mold compared to using an aqueous solution without a release agent.

[0028] Extraction can be achieved, for example, by immersing the lens in an extraction fluid or exposing the lens to a flowing extraction fluid. Extraction may also include one or more of the following: heating the extraction fluid; agitating the extraction fluid; increasing the level of a release agent in the extraction fluid to a level sufficient to detach the lens; mechanically or ultrasonically stirring the lens; and incorporating at least one filtration or extraction agent into an aqueous solution until a level sufficient to promote adequate removal of unreacted components from the lens. The above operations can be performed in batch or continuous methods, with or without heating, agitation, or both. The lens can be hydrated before or after removal from the lens mold.

[0029] The lenses can then be transferred to a packaging process, where the lenses and packaging liquid are deposited into a packaging base having cavities therein. The packaging liquid may contain an isotonic saline solution to prevent dehydration and keep the lenses in a wear-ready state. The packaging base can be hermetically sealed with any suitable sealing material, including, for example, aluminum laminate foil, which may contain aluminum sandwiched between a polyester printed material layer and an oriented polypropylene layer to form a contact lens blister package. The contact lens blister packages can be joined together by continuous foil sheets having perforations therein to provide an array of blister packages comprising two or more individual blister packages, wherein the perforations are aligned on the edges between the blister packages, allowing individual blister packages to be separated from the blister package array. The packaged lenses can then be transferred to a sterilization process, where the packaged lenses are sterilized by placing the blister packages in a sterilization unit (such as an autoclave) under elevated humidity, temperature, and pressure for a period of time.

[0030] Reactive mixtures "Conventional hydrogels" refer to polymer networks made from components that do not contain any siloxy, siloxane, or carbosiloxane groups. Conventional hydrogels can be prepared from reactive mixtures containing hydrophilic monomers. Examples include 2-hydroxyethyl methacrylate ("HEMA"), N-vinylpyrrolidone ("NVP"), N,N-dimethylacrylamide ("DMA"), or vinyl acetate. Conventional hydrogels can also be formed from polyvinyl alcohol. Conventional hydrogel lenses may include a coating, and the coating may be the same as or different from the substrate material. Conventional hydrogels may contain additives such as polyvinylpyrrolidone, and comonomers including phosphorylcholine, methacrylic acid, etc. Examples of conventional hydrogels include, but are not limited to, etafilcon, genfilcon, hilafilcon, lenefilcon, nesofilcon, omafilcon, polymacon, and vifilcon, including all their variations.

[0031] "Organosilicon hydrogel" refers to a polymer network made of at least one hydrophilic component and at least one organosilicon-containing component. Examples of suitable types of hydrophilic components that may be present in the reactive mixture include (meth)acrylates, styrene, vinyl ethers, (meth)acrylamide, N-vinyl lactam, N-vinylamide, N-vinylimide, N-vinylurea, O-vinylcarbamate, O-vinyl carbonate, other hydrophilic vinyl compounds, and mixtures thereof. The organosilicon-containing component may contain at least one polymerizable group (e.g., (meth)acrylate, styrene, vinyl ether, (meth)acrylamide, N-vinyl lactam, N-vinylamide, O-vinylcarbamate, O-vinyl carbonate, vinyl group, or mixtures thereof), at least one siloxane group, and one or more linking groups (which may be bonds) connecting one or more polymerizable groups to one or more siloxane groups. The organosilicon-containing component may, for example, contain from about 1 siloxane repeating unit to 220 siloxane repeating units. The organosilicon-containing component may also contain at least one fluorine atom. Silicone hydrogel lenses may include a coating, and the coating may be the same as or different from the substrate. Examples of suitable silicone hydrogels may include acquafilcon, asmofilcon, balafilcon, comfilcon, delefilcon, enfilcon, fanfilcon, formofilcon, galyfilcon, kalificlon, lotrafilcon, narafilcon, riofilcon, samfilcon, senofilcon, serafilcon, somofilcon, stenfilcon, and verofilcon, including all their variants.

[0032] Initiator The reactive mixture contains a photoinitiator. This photoinitiator absorbs (and is activated by) light of various wavelengths, such as UV wavelengths and / or visible wavelengths. The photoinitiator absorbs light in the visible range of the electromagnetic spectrum (approximately 380 nm to approximately 780 nm). Suitable visible light photoinitiators may include, but are not limited to, aromatic α-hydroxy ketones, alkoxyoxophenyl ketones, acetophenones, acylphosphine oxides, diacylphosphine oxides, and tertiary amine diketones, mixtures thereof, etc. Examples of photoinitiators include, but are not limited to, 1-hydroxycyclohexylphenyl ketone, 2-hydroxy-2-methyl-1-phenyl-prop-1-one, bis(2,6-dimethoxybenzoyl)-2,4-4-trimethylpentylphosphine oxide (DMBAPO), bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide (Irgacure819), 2,4,6-trimethylbenzyl diphenylphosphine oxide and 2,4,6-trimethylbenzoyl diphenylphosphine oxide, methyl benzoin, and combinations of camphorquinone and ethyl 4-(N,N-dimethylamino)benzoate. An effective amount of the initiator that can initiate the photopolymerization of the reactive mixture (including about 0.1 parts by weight to about 2 parts by weight per 100 parts of one or more reactive monomers) is included in the reactive mixture.

[0033] The reactive mixture may also contain a thermal initiator that decomposes at a certain rate depending on the temperature. The thermal initiator may include, but is not limited to, azo compounds such as 1,1'-azobisisobutyronitrile and 4,4'-azobis(4-cyanopentanoic acid), peroxides such as benzoyl peroxide, tert-butyl peroxide, tert-butyl hydroperoxide, tert-butyl peroxybenzoate, dicumyl peroxide and lauroyl peroxide, peracids such as peracetic acid and potassium persulfate, and combinations thereof.

[0034] Packaging integrity test : Figure 1 This is a schematic diagram of the operational structure of an apparatus 100 used for performing disinfection and packaging integrity testing, as well as for repackaging blister packs into cardboard boxes. Although Figure 1 An example of conveying an array of blister packs into a sterilization chamber 104 is illustrated, but several equivalent methods of conveying arrays of blister packs known in the art are possible. Furthermore, although as... Figure 1 The blister pack arrays described herein are multiple, but the method of the present invention is applicable to methods that utilize one or more blister packs for single packaging.

[0035] Figure 1An example is illustrated by feeding the blister pack array 102 along the direction of arrow A so that it can be placed in a paired, staggered relationship by a product pick-up and rotating device, as shown by arrow B. The staggered blister pack array 102 can also be conveyed to be positioned in the space between the outwardly extending fingers of an endless loop pallet loading shuttle assembly 106, which can be forward-rotated in the direction of arrow C until all the space along its vertical travel can be filled with the paired, staggered blister pack arrays 102. The conveyor assembly can then be adapted to temporarily stop, and a suitable pusher 108 can transfer the vertical stack of the blister pack arrays 102 from the conveyor to the array receiving space of the vertical columns or rows in an inverted pallet 110. The pallet 110 can be intermittently rotated in the direction of arrow D until all the space in its vertical rows can be filled with the staggered paired blister pack arrays 102. Although Figure 1 An array of staggered blister packs is displayed, but a single blister pack array or a single contact lens blister pack can be inserted into tray 110.

[0036] like Figure 1As further illustrated, the array filling tray 110 is conveyed in the direction of arrow E, while being rotated to a horizontal position in the direction of arrow F beforehand, and can be stacked with other similarly filled trays 110 for conveying into the sterilization chamber 104. The sterilization chamber 104 may include an autoclave. As will be discussed below, the sterilization chamber 104 can be operated in such a manner that at least a portion of the packaging fluid present in the defective blister pack array 102 escapes from the blister pack. The stack of trays 110 containing the blister pack array 102 can then be conveyed from the sterilization chamber 104 in the direction of arrow G and introduced into the packaging integrity test unit 112. In the packaging integrity test unit 112, the sterilized blister packs 102 can undergo non-destructive testing to determine the presence of any defective blister pack arrays 102. The operation of the packaging integrity test unit 112 will be described in detail below. Defective packages can be removed from the cycle as indicated by arrow R, and the remaining defect-free packages can be conveyed for packaging as indicated by arrow H, in which trays can be destacking and continuously and individually advanced and inverted. The flipped tray 110 can be positioned to align with the unloading reciprocating conveyor assembly 116, allowing the pusher element to sequentially engage into the vertical row of spaces containing the blister pack arrays on the tray 110, and to transfer the blister pack arrays into the spaces between outwardly extending fingers present on the endless loop conveyor of assembly 116. The conveyor can be rotated forward in the direction of arrow I, and the pusher element slides a series of multiple sterilized blister pack arrays 102 into the open end of a carton 114, which has been aligned with it by a cartoning machine. The filled carton 114 can then be closed and sealed, and conveyed along arrow J to the appropriate location for further processing, such as bundling as indicated by arrow K.

[0037] The sterilization chamber 104 includes a cavity for storing the blister pack array 102 during sterilization cycles. The cavity can be made of any suitable durable material, such as stainless steel or an alloy, which can withstand thermal and pressure conditions during sterilization cycles. The cavity may also include one or more doors to provide access to the cavity, wherein the doors may be designed with tight seals to prevent leakage during sterilization cycles. One or more doors may include locking mechanisms and associated interlocks to prevent the doors from opening during sterilization cycles. The sterilization chamber may also include inlets and outlets, and controllable valves operatively associated with the inlets and outlets to allow controlled flow of fluids and gases into the cavity. The sterilization chamber 104 may also include a pressure control system to manage and maintain a desired pressure level within the cavity, and may include components such as pressure relief valves and pressure transducers and / or strain gauges that transmit pressure data to the control system to monitor and regulate the pressure within the cavity. The sterilization chamber 104 may also include temperature sensors, such as thermocouples or resistance temperature detectors, that transmit temperature data to the control system to measure and control the temperature within the cavity. The sterilization chamber 104 also includes a heating system to achieve and maintain a desired temperature within the chamber. The heating system may include an electric heater or a steam-powered heater located inside the chamber or in an external jacket surrounding the chamber. For steam, a boiler and / or a steam-powered heater may be operatively coupled to the chamber inlet. The sterilization chamber 104 also includes a control system for operating the sterilization cycle, which may be further integrated into a distributed control system for the contact lens production line.

[0038] This control system may include a computer-based control system that can be used to monitor and control various processes within the sterilization chamber. The control system typically includes multiple components, including: sensors: these devices measure the physical properties of the process, such as temperature, pressure, and flow rate; controllers: these devices use data from the sensors to calculate necessary adjustments to the process; actuators: these devices implement control commands from the controllers, such as opening or closing valves; and a human-machine interface (HMI), which may include a graphical user interface that allows operators to monitor and control the process. The control system uses various types of logic control, such as PID controllers, ladder logic, and sequential function charts, to control the process. Logic control can be programmed into the control system software and can be used to ensure that the equipment operates within predefined limits.

[0039] The sterilization cycle can be initiated by the control system sending a signal to the controller associated with the steam system to open one or more inlet valves leading to the chamber. Before, during, and after the sterilization cycle, the instrumentation reports conditions within the various sections of the sterilization chamber 104 to the controller or control system, such as steam pressure and temperature in the pipelines, plant steam pressure and temperature, radiator pressure, air pressure and temperature, water pressure and temperature, valve status, and safety interlock status. The sterilization cycle typically involves increasing the chamber pressure and temperature to a setpoint, maintaining the pressure and temperature at the setpoint for a defined period of time, and releasing the pressure while using, for example, air to cool the chamber. The sterilization cycle setpoint temperature, pressure, and holding time are selected so that contact lens blister packs are safely sterilized without damaging the lenses or blister packs. The rates of increase and decrease in temperature and pressure can be controlled so that the lenses and blister packs are not damaged. For example, if the pressure differential across the seal is greater than the seal strength, reducing the pressure within the chamber may cause the blister packs to burst.

[0040] The selected setpoint temperature can be in the range of approximately 110°C to approximately 140°C. Alternatively, it can be in the range of approximately 110°C to approximately 120°C, approximately 120°C to approximately 130°C, approximately 130°C to approximately 140°C, or any range therebetween. The setpoint pressure can be selected in the range of approximately 300 kPa to approximately 450 kPa. Alternatively, it can be in the range of approximately 300 kPa to approximately 350 kPa, approximately 350 kPa to approximately 400 kPa, approximately 400 kPa to approximately 450 kPa, or any range therebetween. The ramp time for the sterilizer unit to reach the temperature setpoint can be in the range of approximately 1 minute to approximately 5 minutes. Alternatively, it can be in the range of approximately 1 minute to approximately 2 minutes, approximately 2 minutes to approximately 3 minutes, approximately 3 minutes to approximately 5 minutes, or any range therebetween. The ramp time for the sterilizer unit to reach the pressure setpoint can be in the range of approximately 1 minute to approximately 5 minutes. Alternatively, the duration of the sterilizer cycle may be within the range of approximately 1 minute to approximately 2 minutes, approximately 2 minutes to approximately 3 minutes, approximately 3 minutes to approximately 5 minutes, or any range therebetween. The holding time of the sterilizer cycle may be a value within the range of approximately 10 minutes to approximately 30 minutes. Alternatively, the duration may be within the range of approximately 10 minutes to approximately 20 minutes, approximately 20 minutes to approximately 25 minutes, approximately 20 minutes to approximately 30 minutes, or any range therebetween. The sterilizer may have a descent time for the sterilizer unit to reach atmospheric pressure within the range of approximately 5 minutes to approximately 20 minutes. Alternatively, the duration may be within the range of approximately 5 minutes to approximately 10 minutes, approximately 10 minutes to approximately 15 minutes, approximately 15 minutes to approximately 20 minutes, or any range therebetween. The sterilizer may have a descent time for the sterilizer unit to reach ambient temperature within the range of approximately 5 minutes to approximately 20 minutes. Alternatively, the duration may be within the range of approximately 5 minutes to approximately 10 minutes, approximately 10 minutes to approximately 15 minutes, approximately 15 minutes to approximately 20 minutes, or any range therebetween.

[0041] As discussed above, contact lens blister packs can be damaged by the sterilization cycle or other parts of the manufacturing process, such as during transport and handling. Additionally, the seal formed between the blister pack base and cap may be defective; the cap may be defective, or the pack base may be defective, making it impossible to maintain the sterility of the blister pack. For these and other reasons, a process may be needed to determine whether each blister pack in a manufacturing batch is defective. One way to determine whether a blister pack contains defects that do not compromise its sterility is to select operating conditions for the sterilization unit, such as setpoint temperature, setpoint pressure, and holding time, such that a portion of the packaging fluid can be drained from the defective blister pack at points before, during, or after the sterilization cycle. After passing through the sterilization unit, the blister pack can then be analyzed to determine whether it contains low doses of packaging solution or no packaging solution at all.

[0042] Several methods exist to induce a portion of the packaging solution, containing water as its primary component, to escape from a defective blister pack. One method involves increasing the temperature and pressure within the sterilization chamber while maintaining both above the water saturation line. Once the set temperature is reached and the holding time expires, the pressure can be reduced while maintaining a relatively constant temperature, causing both pressure and temperature to drop below the water saturation line. If the blister pack is defective, as the pressure decreases, a portion of the packaging solution may flash into vapor and subsequently escape from the blister pack. The temperature and pressure within the chamber can then be reduced to ambient temperature and pressure, completing the sterilization cycle.

[0043] Figure 2 This is a phase diagram illustrating methods for increasing temperature and pressure before lowering the pressure below the saturation line. Figure 2 In this method, the process begins at a first point 202 in the liquid region of the phase diagram. The method proceeds by increasing the pressure and temperature in the sterilizer unit from a first pressure and a first temperature corresponding to the first point 202 to a second pressure and a second temperature corresponding to the second point 204. (As...) Figure 2As shown, the pressure and temperature in the sterilizer are increased while remaining within the liquid phase region of the aqueous phase diagram and avoiding entry into the gas phase region. Once the second point 204 is reached, the pressure and temperature can be maintained for a period of time. This method can be carried out by reducing the pressure while maintaining a relatively stable temperature until the third point 206, so that the temperature and pressure in the sterilizer unit are in the gas phase region of the aqueous phase diagram. The conditions in the sterilizer unit can be maintained at the third point 206 for a period of time to allow at least a portion of the packaging solution within the defective blister pack to flash into vapor. Then, this method can be carried out by reducing the temperature and / or pressure so that the conditions within the sterilizer unit correspond to the first point 202.

[0044] Another method for draining a portion of the packaging solution is to increase the temperature and pressure within the sterilization chamber while maintaining these levels above the water saturation line. The relative humidity of the air within the chamber can be controlled such that it is lower than the relative humidity of the top space within the blister pack during sterilization cycles. A selectable holding time allows at least a portion of the packaging solution to evaporate from the defective blister pack. The temperature and pressure within the chamber can then be reduced to ambient temperature and pressure, completing the sterilization cycle.

[0045] Figure 3 This is a phase diagram illustrating a disinfection cycle under controlled relative humidity. Figure 3 In this method, the process begins at a first point 302 (first pressure and first temperature) in the liquid portion of the phase diagram. The method continues by increasing the pressure and temperature in the sterilizer unit from the first pressure and first temperature corresponding to the first point 302 along path 304 to a second pressure and second temperature to a second point 306. Figure 3 As shown, while remaining within the liquid phase region of the aqueous phase diagram and avoiding entry into the gas phase region, the pressure and temperature in the sterilizer increase. Once point 304 is reached, the pressure and temperature can be maintained for a certain period of time while controlling the relative humidity of the sterilizer unit so that the relative humidity of the sterilizer unit is lower than the relative humidity in the top space of the contact lens blister. The holding time can be selected so that a portion of the packaging solution in the defective blister package evaporates from and is discharged from the defective blister package.

[0046] Another method for draining a portion of the packaging solution can be to circulate the pressure in the chamber to a relatively high pressure and then reduce the pressure to a relatively low pressure to "pump" a portion of the packaging solution out of the defective package. This pumping cycle can be performed before or after a sterilization cycle. The pumping cycle can include increasing the pressure in the sterilizer unit from a first pressure to a higher second pressure, where the second pressure is higher than the first pressure; decreasing the pressure in the sterilizer unit from the second pressure to a third pressure, where the third pressure is lower than the second pressure; increasing the pressure in the sterilizer unit from the third pressure to a fourth pressure, where the fourth pressure is higher than the third pressure; and decreasing the pressure in the sterilizer unit from the fourth pressure to a fifth pressure, where the fifth pressure is lower than the fourth pressure. In the presence of defective packaging, a portion of the packaging solution can be drained by at least one of the following: decreasing the pressure in the sterilizer unit from the second pressure to the third pressure and / or decreasing the pressure in the sterilizer unit from the fourth pressure to the fifth pressure. Although only two pumping cycles are described, the pumping cycle can be repeated any number of times to drain a portion of the packaging solution.

[0047] Another method to drain a portion of the packaging solution is to raise the temperature and lower the pressure in the sterilization chamber below the saturation line, maintaining this position for a period of time to allow a portion of the packaging solution to flash into vapor and escape from the defective blister pack. This evacuation cycle can be performed before, during, or after the sterilization cycle.

[0048] Multiple technologies can be combined to discharge at least a portion of the packaged fluid. For example, a pumping cycle can be combined with a sterilization cycle characterized by relative humidity control. A pumping cycle can be combined with a sterilization cycle that reduces pressure below the saturation line. A sterilization cycle may include elements of relative humidity control and pressure drop below the saturation line.

[0049] Figure 4a is a schematic diagram of a blister pack array 102. As illustrated, the blister pack array 102 includes five adjacently positioned contact lens blister packs 401. Each blister pack 401 includes a packaging base 402 having a cavity 404 for receiving a contact lens 406 immersed in a packaging solution, and wherein the blister pack array 102 is hermetically covered by a single flexible foil seal 408 so that it can be separated into individual blister packs 401 along a perforation line 410, each blister pack containing a single contact lens.

[0050] Figure 4b is a side profile view of a single blister pack array 102. As shown in Figure 4b, the blister pack 401 includes a cavity 404 sealed by a foil seal 408. Figure 4c is a side profile view of two nested, staggered blister pack arrays 102 such that the foil seal 408 of each blister pack 401 faces outward.

[0051] Once the blister pack array 102 has been sterilized and a portion of the packaging solution has been drained from the defective blister packs, the blister pack array 102 can be introduced into the packaging integrity testing unit 112. The packaging integrity testing unit 112 includes means for determining whether the blister packs within the blister pack array 102 may be defective. Although the following description may be directed at blister pack arrays, the method is equivalent to staggered blister pack arrays and individual blister packs.

[0052] Figure 5 A method 500 for identifying defective blister packs is illustrated. Method 500 begins by providing a blister pack array 102 from a sterilization process that includes the step of draining a portion of the packaging solution from the defective blister pack as described above. Method 500 continues by heating the blister pack array 102 using a heat source 502. Heating can be achieved using any suitable method, such as heating the blister packs using infrared energy and / or thermal energy. Heating can raise the temperature of at least one of the foil seal, packaging solution, lens, and / or packaging base. For defective blister packs containing low doses of packaging solution, the heat transferred to the defective pack may result in the defective pack having a higher temperature than undefective packs. After heating, the foil and packaging solution of the defective blister pack may be at a higher relative temperature than those of the undefective blister pack. After heating, the blister pack array 102 may be positioned below a thermal imaging camera 504 containing a sensor sensitive to infrared wavelengths in the range of about 1,000 nm to about 14,000 nm.

[0053] Several methods can be used to identify defective blister packs, including by examining the intensity of infrared radiation emitted from the heated pack, and by observing the bubble size of the packaged solution through the foil seal 408. The bubble size can be related to the amount of packaged solution, thus a nominal dose of packaged solution may have a nominal bubble size, and a defective blister pack may have a bubble size smaller than the nominal bubble size. Alternatively, defective blister packs can be identified by examining the thermal characteristics of the heated blister pack array 102. Defective blister packs may have different thermal characteristics due to the temperature rise caused by heating, and can therefore be identified by comparing the observed thermal characteristics with the nominal thermal characteristics and determining whether the observed thermal characteristics adequately match the nominal thermal characteristics. Defective blister packs can also be identified by comparing the average surface temperature of the blister pack with the nominal average surface temperature. The nominal measurements for each method can be readily obtained by measuring representative samples of known good blister packs. Multiple thermal cameras 504 may be present, positioned to capture thermal images of various portions of the blister pack array 102. These cameras include, for example, thermal cameras 504 positioned to capture side profile images of the blister pack array 102, or thermal cameras 504 positioned to capture bottom profile images of the blister pack 102, such as thermal images of the cavity 404. When a thermal camera 504 is positioned to capture a thermal image of the cavity 404, the bubble size can be observed through the material of the cavity 404. Similarly, an optical camera 506 may be positioned below the cavity 404 to optically measure the bubble size.

[0054] Figure 6 A method 600 for identifying defective blister packs is illustrated. Method 600 begins by providing a blister pack array 102 from a sterilization process that includes the step of draining a portion of the packaging solution from the defective blister packs as described above. Method 600 continues by measuring the mass of the blister pack array 102 using a mass balance 602. The measured mass can be compared to a nominal mass, and if the measured mass deviates from the expected nominal mass of the type of contact lens blister pack being inspected, the blister pack array 102 is considered defective.

[0055] Figure 7A method 700 for identifying defective blister packs is illustrated. Method 700 begins at block 702, where an array of blister packs (e.g., blister pack array 102 on FIG. 4a) is derived from a sterilization process that includes the step of draining a portion of the packaging solution from the defective blister packs as described above. In block 704, the blister pack array may be contacted with one or more force transducers, such as load cells, to generate signals corresponding to measured forces acting on one or more blister packs in the array (e.g., blister pack 401 on FIG. 4a). In block 706, the forces measured by the force transducers may be compared with nominal measurements to determine whether the blister packs are potentially defective. For blister packs without packaging defects, the volume of the headspace at ambient temperature does not change after the application of the seal through the sterilization cycle and the draining of a portion of the packaging solution. The integrity of the seal (e.g., foil seal 408 on FIG. 4a) is maintained throughout the sterilization process, and therefore the deflection of the seal, measured in response to the application of force, should remain relatively constant after the sterilization process. For defective blister packs, the volume of the headspace may change when a portion of the packaging fluid is drained from the blister pack during sterilization cycles and / or the draining of a portion of the packaging fluid. This change in headspace volume results in an increased measured deflection of the foil seal in the defective blister pack. A force transducer can be used in several ways to determine if a blister pack is defective. The force transducer can contact the blister pack foil and the deflection of the foil can be measured over a time period to determine if the measured deflection has changed. The packaging type and the measured deflection can be compared to the nominal expected deflection over time of the force applied to the foil through the transducer to determine if the measured deflection is greater than the nominal expected deflection. If the measured deflection is greater than the nominal expected deflection, the packaging can be considered defective. Alternatively, the force transducer and foil can contact at a calibration distance, and the resulting measured force can be used to determine if the foil deflects beyond the expected nominal amount. The foil deflection deviating from the nominal amount can then be correlated with a defect in the packaging.

[0056] Figure 8 Examples are provided for implementation. Figure 7 The apparatus of method 700. For example... Figure 8 As shown, tray 110 includes multiple blister pack arrays 102. A force transducer body 802 is illustrated having multiple force transducers 804 operably disposed on fingers extending from the force transducer body. The fingers extend into the space between the multiple blister pack arrays 102, and the multiple force transducers 804 contact foil seals on one or more blister packs within the blister pack array 102. The forces measured by the multiple force transducers 804 can then be correlated with packaging conditions, and whether the packaging is defective can be determined.

[0057] Additional Implementation Plan Therefore, this disclosure provides a method for detecting defects in contact lens packaging by using a sterilization unit to drain a portion of the liquid within the contact lens packaging and detecting changes in the volume of the liquid within the contact lens packaging. This method may include any of the various features disclosed herein.

[0058] Implementation Scheme 1. A method comprising: introducing a contact lens blister pack into a sterilizer unit, wherein the contact lens blister pack includes a packaging base having a cavity, a contact lens disposed in the cavity, a packaging solution disposed in the cavity, and a sealing film formed over the cavity; controlling operating conditions of the sterilizer unit such that if a defect exists in the contact lens blister pack, at least a portion of the packaging solution is discharged from the contact lens blister pack; introducing the contact lens blister pack into a packaging integrity testing unit; and detecting whether the contact lens blister pack is defective based at least on the amount of remaining packaging solution.

[0059] Implementation Scheme 2. According to the method of Implementation Scheme 1, wherein controlling the operating conditions of the sterilizer unit includes: increasing the pressure and temperature in the sterilizer unit from a first pressure and a first temperature to a second pressure and a second temperature, wherein the first temperature and the second temperature are in the liquid phase region of the aqueous phase diagram, wherein the pressure and temperature in the sterilizer are increased while remaining in the liquid phase region of the aqueous phase diagram and avoiding entry into the gas phase region of the aqueous phase diagram; maintaining the second pressure and the second temperature for a period of time; and reducing the pressure in the sterilizer unit to a third pressure, such that the temperature and pressure in the sterilizer unit are in the gas phase region of the aqueous phase diagram.

[0060] Implementation Scheme 3. The method according to any one of Implementation Schemes 1 to 2 further includes: flash evaporating a portion of the packaging solution into vapor.

[0061] Implementation Scheme 4. The method according to any one of Implementation Schemes 1 to 3, wherein controlling the operating conditions of the sterilizer unit includes: increasing the pressure and temperature in the sterilizer unit from a first pressure and a first temperature to a second pressure and a second temperature, wherein the first temperature and the second temperature are in the liquid phase region of the aqueous phase diagram, wherein the pressure and temperature in the sterilizer are increased while remaining in the liquid phase region of the aqueous phase diagram and avoiding entry into the gas phase region of the aqueous phase diagram; maintaining the second pressure and the second temperature for a period of time; and controlling the relative humidity of the sterilizer unit such that the relative humidity of the sterilizer unit is less than the relative humidity in the top space of the contact lens blister pack.

[0062] Implementation Scheme 5. The method according to any one of Implementation Schemes 1 to 4 further includes: evaporating at least a portion of the packaging solution.

[0063] Implementation Scheme 6. The method according to any one of Implementation Schemes 1 to 5, wherein controlling the operating conditions of the sterilizer unit includes: increasing the pressure in the sterilizer unit from a first pressure to a higher second pressure, wherein the second pressure is higher than the first pressure; decreasing the pressure in the sterilizer unit from the second pressure to a third pressure, wherein the third pressure is lower than the second pressure; increasing the pressure in the sterilizer unit from the third pressure to a fourth pressure, wherein the fourth pressure is higher than the third pressure; and decreasing the pressure in the sterilizer unit from the fourth pressure to a fifth pressure, wherein the fifth pressure is lower than the fourth pressure.

[0064] Implementation Scheme 7. The method according to any one of claims 1 to 6, wherein a portion of the packaging solution is discharged by at least one of the following: reducing the pressure in the sterilizer unit from the second pressure to the third pressure and / or reducing the pressure in the sterilizer unit from the fourth pressure to the fifth pressure.

[0065] Implementation Scheme 8. The method according to any one of Implementation Schemes 1 to 7, wherein the packaging integrity testing unit includes a heat source configured to heat the contact lens blister pack and a thermal imaging sensor configured to measure infrared radiation emitted from the blister pack.

[0066] Implementation Scheme 9. The method according to any one of Implementation Schemes 1 to 8, wherein detecting the defect comprises: identifying the bubble size of the packaging solution by relating measured infrared radiation emitted from the contact lens to the bubble size of the packaging solution, comparing the bubble size of the packaging solution to a nominal bubble size of the packaging solution, and determining whether the bubble size of the packaging solution is smaller than the nominal bubble size of the packaging solution.

[0067] Implementation Scheme 10. The method according to any one of Implementation Schemes 1 to 9, wherein detecting the defect comprises: identifying the thermal characteristics of the blister pack by correlating the measured infrared radiation emitted from the contact lens with the thermal characteristics of the contact lens blister pack, comparing the thermal characteristics of the contact lens blister pack with the nominal thermal characteristics of the contact lens blister pack, and determining whether the thermal characteristics of the contact lens blister pack correspond to the nominal thermal characteristics of the contact lens blister pack.

[0068] Implementation Scheme 11. The method according to any one of Implementation Schemes 1 to 10, wherein detecting the defect comprises: identifying the average surface temperature of the contact lens blister packaging by correlating the measured infrared radiation emitted from the contact lens blister packaging with the average surface temperature of the contact lens blister packaging; comparing the average surface temperature of the contact lens blister packaging with the nominal average surface temperature of the contact lens blister packaging; and determining whether the average surface temperature of the contact lens blister packaging corresponds to the nominal average surface temperature of the contact lens blister packaging.

[0069] Implementation Scheme 12. The method according to any one of Implementation Schemes 1 to 11, wherein the packaging integrity unit includes a mass balance, and wherein detecting the defect includes: measuring the mass of the contact lens blister package, comparing the mass of the contact lens blister package with the nominal mass of the contact lens blister package, and determining whether the mass of the contact lens blister package corresponds to the nominal mass of the contact lens blister package.

[0070] Implementation Scheme 13. The method according to any one of Implementation Schemes 1 to 12, wherein the packaging integrity unit includes a force transducer, and wherein detecting the defect includes: contacting the force transducer with the film.

[0071] Implementation Scheme 14. The method according to any one of Implementation Schemes 1 to 14, wherein the packaging integrity unit includes a force transducer, and wherein detecting the defect includes: contacting the force transducer with the film, measuring the deflection of the film over time, comparing the deflection of the film over time with a nominal expected deflection over time, and determining whether the measured deflection of the film over time corresponds to the nominal expected deflection over time, and / or wherein the packaging integrity unit includes a force transducer, and wherein detecting the defect includes: contacting the force transducer with the film at a predetermined distance, measuring a force using the force transducer, comparing the force with a nominal expected force, and determining whether the measured force corresponds to the nominal expected force.

[0072] Implementation Scheme 15. A method comprising: introducing a contact lens blister pack into a sterilizer unit, wherein the contact lens blister pack includes a packaging base having a cavity, a contact lens disposed in the cavity and a packaging solution, and forming a sealed film over the cavity, wherein the contact lens blister pack includes a defect; controlling operating conditions of the sterilizer unit such that at least a portion of the packaging solution is discharged from the contact lens blister pack through the defect; and introducing the contact lens blister pack into a packaging integrity testing unit and detecting the defect.

[0073] Implementation Scheme 16. The method according to Implementation Scheme 15, wherein the packaging integrity testing unit includes a heat source configured to heat the contact lens blister packaging and a thermal imaging sensor configured to measure infrared radiation emitted from the contact lens blister packaging, wherein detecting the defect includes: identifying the bubble size of the packaging solution by correlating the measured infrared radiation emitted from the contact lens with the bubble size of the packaging solution, comparing the bubble size of the packaging solution with the nominal bubble size of the packaging solution, and determining whether the bubble size of the packaging solution is smaller than the nominal bubble size of the packaging solution, and / or wherein detecting the defect includes: identifying the bubble size of the packaging solution by correlating the measured infrared radiation emitted from the contact lens with the thermal characteristics of the contact lens blister packaging. The thermal characteristics of the contact lens blister packaging are compared with the nominal thermal characteristics of the contact lens blister packaging, and it is determined whether the thermal characteristics of the contact lens blister packaging correspond to the nominal thermal characteristics of the contact lens blister packaging, and / or the detection of the defect includes: identifying the average surface temperature of the contact lens blister packaging by correlating the measured infrared radiation emitted from the contact lens blister packaging with the average surface temperature of the contact lens blister packaging, comparing the average surface temperature of the contact lens blister packaging with the nominal average surface temperature of the contact lens blister packaging, and determining whether the average surface temperature of the contact lens blister packaging corresponds to the nominal average surface temperature of the contact lens blister packaging.

[0074] Implementation Scheme 17. The method according to any one of Implementation Schemes 15 to 16, wherein the packaging integrity unit includes a mass balance, and wherein detecting the defect includes: measuring the mass of the contact lens blister package, comparing the mass of the contact lens blister package with the nominal mass of the contact lens blister package, and determining whether the mass of the contact lens blister package corresponds to the nominal mass of the contact lens blister package.

[0075] Implementation Scheme 18. The method according to any one of Implementation Schemes 15 to 17, wherein the packaging integrity unit includes a force transducer, and wherein detecting the defect includes: contacting the force transducer with the film, measuring the deflection of the film over time, comparing the deflection of the film over time with a nominal expected deflection over time, and determining whether the measured deflection of the film over time corresponds to the nominal expected deflection over time.

[0076] Implementation Scheme 19. The method according to any one of Implementation Schemes 15 to 18, wherein the packaging integrity unit includes a force transducer, and wherein detecting the defect includes: contacting the force transducer with the film at a predetermined distance, measuring a force using the force transducer, comparing the force with a nominal expected force, and determining whether the measured force corresponds to the nominal expected force.

[0077] Implementation Scheme 20. The method according to any one of Implementation Schemes 15 to 19, wherein the sterilizer unit and the packaging integrity testing unit are components of the contact lens production line.

[0078] It should be understood that this disclosure is not limited to a specific method, although the method may vary. Furthermore, it should be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. All numerical values ​​and ranges disclosed herein may vary in some quantities. Whenever a numerical range with a lower and upper limit is disclosed, any numerical value falling within that range and any included range is specifically disclosed. Although various embodiments are discussed herein, the invention covers all combinations of all those embodiments. As used herein, unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “the” include both singular and plural references. Furthermore, the word “may” is used throughout this application in a permissive sense (i.e., potentially, capable) rather than a mandatory sense (i.e., must). The term “comprising” and its derivatives mean “including but not limited to.” The term “connected” means a direct or indirect connection. If the use of words or terms in this specification conflicts in any way with one or more patents or other documents that may be incorporated herein by reference, the definitions consistent with this specification should be adopted for the purposes of understanding the invention.

[0079] For the sake of brevity, this document only explicitly discloses certain ranges. However, a range from any lower limit can be combined with any upper limit to describe a range not explicitly stated, and a range from any lower limit can be combined with any other lower limit to describe a range not explicitly stated, just as a range from any upper limit can be combined with any other upper limit to describe a range not explicitly stated. Additionally, whenever a range of values ​​having a lower and upper limit is disclosed, any value falling within that range and any included range are specifically disclosed. Specifically, each range of values ​​disclosed herein (in the form of “about a to about b” or equivalent “about a to b” or equivalent “from about ab”) should be understood as listing every value and range covered within a broader range of values, even if not explicitly stated. Thus, each point or single value can be used as its own lower or upper limit, combined with any other point or single value or any other lower or upper limit to describe a range not explicitly stated.

[0080] The scope of this disclosure includes any feature or combination of features disclosed herein (explicitly or implicitly), or any generalization thereof, whether or not it alleviates any or all of the problems addressed herein. Various advantages of this disclosure have been described herein; however, embodiments may provide some, all, or no of these advantages, or may provide other advantages.

Claims

1. A method comprising: A contact lens blister pack is introduced into the sterilizer unit, wherein the contact lens blister pack includes a packaging base with a cavity, a contact lens disposed in the cavity, a packaging solution disposed in the cavity, and a material forming a seal above the cavity; The operating conditions of the sterilizer unit are controlled such that if there is a defect in the contact lens blister packaging, at least a portion of the packaging solution is discharged from the contact lens blister packaging; The contact lens blister packaging is introduced into the packaging integrity testing unit; as well as The presence of defects in the contact lens blister packaging is determined at least based on the amount of remaining packaging solution.

2. The method according to claim 1, wherein, The operating conditions for controlling the sterilizer unit include: The pressure and temperature in the sterilizer unit are increased from a first pressure and a first temperature to a second pressure and a second temperature, wherein the first temperature and the second temperature are in the liquid phase region of the aqueous phase diagram, wherein the pressure and temperature in the sterilizer are increased while remaining in the liquid phase region of the aqueous phase diagram and avoiding entry into the gas phase region of the aqueous phase diagram. Maintain the second pressure and the second temperature for a specified period of time; and The pressure in the sterilizer unit is reduced to a third pressure, such that the temperature and pressure in the sterilizer unit are in the gas phase region of the aqueous phase diagram.

3. The method according to claim 2, further comprising: A portion of the packaging solution is flash-evaporated into vapor.

4. The method according to claim 1, wherein, The operating conditions for controlling the sterilizer unit include: The pressure and temperature in the sterilizer unit are increased from a first pressure and a first temperature to a second pressure and a second temperature, wherein the first temperature and the second temperature are in the liquid phase region of the aqueous phase diagram, wherein the pressure and temperature in the sterilizer are increased while remaining in the liquid phase region of the aqueous phase diagram and avoiding entry into the gas phase region of the aqueous phase diagram. Maintain the second pressure and the second temperature for a specified period of time; and The relative humidity of the sterilizer unit is controlled such that the relative humidity of the sterilizer unit is less than the relative humidity in the top space of the contact lens blister pack.

5. The method according to claim 4, further comprising: At least a portion of the packaging solution is evaporated.

6. The method according to claim 1, wherein, The operating conditions for controlling the sterilizer unit include: The pressure in the sterilizer unit is increased from a first pressure to a second pressure, wherein the second pressure is higher than the first pressure; The pressure in the sterilizer unit is reduced from the second pressure to a third pressure, wherein the third pressure is lower than the second pressure; Increasing the pressure in the sterilizer unit from the third pressure to a fourth pressure, wherein the fourth pressure is higher than the third pressure; and The pressure in the sterilizer unit is reduced from the fourth pressure to a fifth pressure, wherein the fifth pressure is lower than the fourth pressure.

7. The method according to claim 6, wherein, A portion of the packaging solution is discharged by at least one of the following: reducing the pressure in the sterilizer unit from the second pressure to the third pressure and / or reducing the pressure in the sterilizer unit from the fourth pressure to the fifth pressure.

8. The method according to claim 1, wherein, The packaging integrity testing unit includes a heat source configured to heat the contact lens blister pack and a thermal imaging sensor configured to measure infrared radiation emitted from the blister pack.

9. The method according to claim 1, wherein, Detecting the defect includes: identifying the bubble size of the packaging solution by correlating measured infrared radiation emitted from the contact lens with the bubble size of the packaging solution; comparing the bubble size of the packaging solution with the nominal bubble size of the packaging solution; and determining whether the bubble size of the packaging solution is smaller than the nominal bubble size of the packaging solution.

10. The method according to claim 1, wherein, Detecting the defect includes: identifying the thermal characteristics of the blister pack by correlating measured infrared radiation emitted from the contact lens with the thermal characteristics of the contact lens blister pack; comparing the thermal characteristics of the contact lens blister pack with the nominal thermal characteristics of the contact lens blister pack; and determining whether the thermal characteristics of the contact lens blister pack correspond to the nominal thermal characteristics of the contact lens blister pack.

11. The method according to claim 1, wherein, Detecting the defect includes: identifying the average surface temperature of the contact lens blister pack by correlating measured infrared radiation emitted from the contact lens blister pack with the average surface temperature of the contact lens blister pack; comparing the average surface temperature of the contact lens blister pack with the nominal average surface temperature of the contact lens blister pack; and determining whether the average surface temperature of the contact lens blister pack corresponds to the nominal average surface temperature of the contact lens blister pack.

12. The method according to claim 1, wherein, The packaging integrity testing unit includes a mass balance, and the detection of the defect includes: measuring the mass of the contact lens blister pack, comparing the mass of the contact lens blister pack with the nominal mass of the contact lens blister pack, and determining whether the mass of the contact lens blister pack corresponds to the nominal mass of the contact lens blister pack.

13. The method according to claim 1, wherein, The packaging integrity testing unit includes a force transducer, and detecting the defect includes contacting the force transducer with the material forming the seal.

14. The method according to claim 1, wherein, The packaging integrity testing unit includes a force transducer, and the detection of the defect includes: contacting the force transducer with the material forming the seal, measuring the deflection of the material over time, comparing the deflection of the material over time with a nominal expected deflection over time, and determining whether the measured deflection of the material over time corresponds to the nominal expected deflection over time, and / or the detection of the defect includes: contacting the force transducer with the material forming the seal at a predetermined distance, measuring a force using the force transducer, comparing the force with a nominal expected force, and determining whether the measured force corresponds to the nominal expected force.

15. The method according to claim 1, wherein, The material forming the seal above the cavity is a multilayer film.

16. The method according to claim 1, wherein, The material forming the seal above the cavity is a multilayer film comprising at least a foil layer and a sealing layer.

17. A method comprising: A contact lens blister pack is introduced into a sterilizer unit, wherein the contact lens blister pack includes a packaging base with a cavity, a contact lens disposed in the cavity and a packaging solution, and a material forming a seal above the cavity, wherein the contact lens blister pack includes defects; The operating conditions of the sterilizer unit are controlled such that at least a portion of the packaging solution is discharged from the contact lens blister pack through the defect; as well as The contact lens blister packaging is introduced into the packaging integrity testing unit and the defects are detected.

18. The method of claim 17, wherein, The packaging integrity testing unit includes a heat source configured to heat the contact lens blister pack and a thermal imaging sensor configured to measure infrared radiation emitted from the contact lens blister pack. The detection of the defect includes: identifying the bubble size of the packaging solution by correlating the measured infrared radiation emitted from the contact lens with the bubble size of the packaging solution; comparing the bubble size of the packaging solution with the nominal bubble size of the packaging solution; and determining whether the bubble size of the packaging solution is smaller than the nominal bubble size of the packaging solution, and / or The detection of the defect includes: identifying the thermal characteristics of the contact lens blister packaging by correlating the measured infrared radiation emitted from the contact lens with the thermal characteristics of the contact lens blister packaging; comparing the thermal characteristics of the contact lens blister packaging with the nominal thermal characteristics of the contact lens blister packaging; and determining whether the thermal characteristics of the contact lens blister packaging correspond to the nominal thermal characteristics of the contact lens blister packaging, and / or The detection of the defect includes: identifying the average surface temperature of the contact lens blister pack by correlating the measured infrared radiation emitted from the contact lens blister pack with the average surface temperature of the contact lens blister pack; comparing the average surface temperature of the contact lens blister pack with the nominal average surface temperature of the contact lens blister pack; and determining whether the average surface temperature of the contact lens blister pack corresponds to the nominal average surface temperature of the contact lens blister pack.

19. The method of claim 17, wherein, The packaging integrity testing unit includes a mass balance, and the detection of the defect includes: measuring the mass of the contact lens blister pack, comparing the mass of the contact lens blister pack with the nominal mass of the contact lens blister pack, and determining whether the mass of the contact lens blister pack corresponds to the nominal mass of the contact lens blister pack.

20. The method of claim 17, wherein, The packaging integrity testing unit includes a force transducer, and detecting the defect includes: contacting the force transducer with the material forming the seal, measuring the deflection of the material over time, comparing the deflection of the material over time with a nominal expected deflection over time, and determining whether the measured deflection of the material over time corresponds to the nominal expected deflection over time.

21. The method according to claim 17, wherein, The packaging integrity testing unit includes a force transducer, and detecting the defect includes: contacting the force transducer with the material forming the seal at a predetermined distance, measuring a force using the force transducer, comparing the force with a nominal expected force, and determining whether the measured force corresponds to the nominal expected force.

22. The method according to claim 17, wherein, The sterilizer unit and the packaging integrity testing unit are components of the contact lens production line.

23. The method according to claim 17, wherein, The material forming the seal above the cavity is a multilayer film.

24. The method of claim 17, wherein, The material forming the seal above the cavity is a multilayer film comprising at least a foil layer and a sealing layer.

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