Continuous manufacturing of drugs for pulmonary delivery

Abstract

Methods and apparatus for use in continuous manufacturing (CM) of engineered particulate formulations, including formulations containing therapeutic protein or mAbs, are provided. The resulting products have wide ranges of application, and may be formulated for pulmonary drug delivery systems. Pulmonary drug delivery systems produced according to the CM systems / methods may be used instead of conventional IV, SQ or oral route of administrations.

Description

Docket: 98121.00410 (#24-068)CONTINUOUS MANUFACTURING OF DRUGS FOR PULMONARY DELIVERYCROSS REFERENCE TO RELATED APPLICATION

[0001] This application claims priority benefit to a US provisional patent application entitled “Continuous Manufacturing of Drugs for Pulmonary Delivery,” which was filed on September 24, 2024, and assigned Serial No. 63 / 698,113. The entire content of the foregoing US provisional application is incorporated herein by reference.BACKGROUND OF THE INVENTION1. Field of the Invention

[0002] The invention disclosed herein relates to pharmaceutical compounds, and in particular to manufacturing of drug products for pulmonary administration.2. Description of the Related Art

[0003] The ascending multibillion-dollar sales of drugs make the pharmaceutical industry one of the most important pillars in the world economy. Innovative industrial drug development efforts have provided tremendous benefits to humanity, by offering cures for previously incurable medical conditions, replacing complex and expensive treatments to improve the quality of life and extend life expectancy. However, steadily increasing healthcare costs and rising insurance requirements have become a big burden to patients in this current economy. Many of the pharmaceutical manufacturing processes have been designed empirically and it is widely understood that drug manufacturing has been more of an art than science. As for example, the annual cost of inefficient industrial pharmaceutical operations in the US has been estimated to be as high as US $1 Trillion due to drug recalls, contamination, wasted batches and man hours, delayed development, and product loss.

[0004] Biopharmaceuticals (including protein / peptide or monoclonal antibody (mAb)) are very promising and represent a fast-growing share of the market for human medicines. Pharmaceutical manufacturing processes of solid dosage form (tablet / capsule / bulk drug powder) and other popular dosage forms (IV, IM, inhaled, etc.) are typically in the batch mode for both small and macromolecular (biologies) drugs. One of the biggest problems with batch production is that the machines / equipment used to make the drug product must be stopped and1MEl\57920661.v3Docket: 98121.00410 (#24-068) then cleaned and prepared to be used again. As safety concerns regarding handling of materials have increased in recent years, improved containment is required in order to meet the exposure limits and protect from contamination.

[0005] The product and process development in the pharmaceutical industry has largely remained stagnant in conventional batch-based systems, which suffer from a series of “stop- and-starf steps, and consequently long production cycles and human errors. On the other hand, continuous manufacturing (CM) offers a feasible solution to many issues by facilitating the manufacturing of final dosage form in a single non-stop process with no downtime of the equipment involved. The pharmaceutical materials are processed nonstop in the CM setup, eliminating any hold / down time between steps and reducing human involvement and the manifested potential for error / contamination. CM supports processes that can operate in an uninterrupted manner for very long periods of time, thus eliminating time consuming scale-up exercises currently persistent in batch-based manufacturing protocol.

[0006] Small molecule drugs are known to be stable and easy enough to be formulated into a solid dosage form. Since 1980, the therapeutic proteins or peptides have been recognized as biopharmaceutical drugs. The biological drugs (therapeutic proteins including monoclonal antibodies (mAbs)) have been known to exhibit low oral bioavailability due to pre-systemic degradation and poor gastrointestinal (GI) absorption and mostly freeze dried to be reconstituted before intravenous (IV) or subcutaneous (SQ) administration.

[0007] Several technological approaches have been investigated to administer biological drugs orally by protecting degradation at GI lumen and increasing mucosal penetration forming encapsulated particulate system in the form of emulsion, liposomes, or microparticles and providing a physical barrier to the degradative conditions in GI tract. Another approach has involved reducing the luminal activity by co-administration of protease inhibitors, bile salt, fatty acids, chelators or by covalent modification of N- and C- termini of the polypeptides to confer resistance to proteolysis. Ingestible microneedle-based devices and co-administration of mucoadhesive polymers or cell penetrating peptides are also employed to increase mucosal permeability to enhance absorption of biologies manifesting higher bioavailability. This enhancement of bioavailability is still less than 10% and alternative ways of drug delivery are desired.2MEl\57920661.v3Docket: 98121.00410 (#24-068)SUMMARY OF THE INVENTION

[0008] Disclosed herein are methods and apparatus for use in continuous manufacturing (CM) of engineered particulate formulations, including formulations containing therapeutic protein or mAbs. The resulting products have wide ranges of application, and may be formulated for pulmonary drug delivery systems. Pulmonary drug delivery systems produced according to the CM systems / methods may be used instead of conventional IV, SQ or oral route of administrations.

[0009] In some embodiments, the system includes an electrospray apparatus that includes a conveyer belt or other transport mechanism in communication with a tower / chamber associated with an electrospraying device. The conveyor belt / transport mechanism is adapted to transfer carrier particles into the tower / chamber for combination with charged particles generated by the electrospraying device. The charged particles may include spherical core (biodrug) - sheath (excipient(s)) composite microparticles.

[0010] In an aspect, a method for manufacture of particles is provided that includes electrospraying charged particles into a tower or chamber; combining the electrosprayed charged particles with carrier particles conveyed to the tower or chamber to form heterogeneous particles; and recovering the heterogeneous particles from the tower or chamber.

[0011] The electrospraying of the charged particles may include a nozzle. The method may include delivery of a gaseous feed to the tower or chamber in proximity to the nozzle. The temperature of the gaseous feed may be controlled, e.g., heated and / or cooled.

[0012] The electrospraying of the charged particles may include a voltage source and a collector positioned below the nozzle. The collector may take the form of a wire mesh.

[0013] The method may include delivering a drug and excipient emulsion to the nozzle. The drug may be a bio-drug. The excipient may be a sheath.

[0014] The carrier particles may be delivered to the tower or chamber by a conveyor belt. The carrier particles may be delivered to a conveyor belt from a hopper.

[0015] In an aspect, a microencapsulated drug may be manufactured. The microencapsulated drug may include carrier particles decorated with detachable core and sheath microparticles. The carrier particles may be decorated with detachable core and sheath microparticles that are3MEl\57920661.v3Docket: 98121.00410 (#24-068) configured and adapted for inhaling delivery thereof. The carrier particles may be coated or functionalized with the detachable core and sheath microparticles.

[0016] In an aspect, an apparatus is provided for manufacture of particles. The apparatus may include an electrospray device that includes a nozzle and a collector, and that is configured to deliver charged particles to a tower or chamber. The apparatus may include a conveyor belt configured to deliver carrier particles to the tower or chamber for combination with the charged particles. The apparatus may include a gaseous feed source configured to deliver gaseous feed to the tower or chamber in the region of the nozzle.

[0017] A hopper may be configured and positioned to deliver the carrier particles to the conveyor belt. The collector may take the form of a wire mesh. The conveyor belt may include at least one drive element and / or one idler roller.

[0018] In an aspect, the apparatus and method enable continuous manufacturing (CM) of inhalation products containing mAbs that offer a range of advantages not found in conventional systems.

[0019] In an aspect, a computer program product is stored on non-transitory machine-readable media, the computer program product including machine-readable instructions for controlling production of manufactured particles by operation of an electrospraying apparatus that includes a conveyor system for delivery of carrier particles.

[0020] Additional features, functions and benefits of the apparatus, method and microencapsulated drug will be apparent from the description with follows.BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The features and advantages of the invention are apparent from the following description taken in conjunction with the accompanying drawings in which:

[0022] FIG. 1 is a schematic diagram depicting a system / apparatus for continuous manufacturing of composite particles having a range of applications, e.g., for generation of pulmonary drug bioformulations;

[0023] FIG. 2 is a photomicrograph depicting encapsulated bovine serum albumin (BSA) inside Poly(lactic-co-glycolic) acid (PLGA);4MEl\57920661.v3Docket: 98121.00410 (#24-068)

[0024] FIG. 3 is an SEM image of encapsulated insulin on lactose powder;

[0025] FIG. 4 is a graphic showing data related to Fourier Transform Infrared (FTIR) spectroscopy of insulin in water before electrospray;

[0026] FIG. 5 is a graphic showing data related to FTIR spectroscopy of the emulsion of FIG. 4, after the electrospray;

[0027] FIG. 6 is a graph depicting a Circular dichroism (CD) spectrum for pure insulin;

[0028] FIG. 7 is a graph depicting a CD spectrum for samples after electrospray on the production belt;

[0029] FIG. 8 is a representative SEM image of mono bevacizumab (BEV);

[0030] FIG. 9 is an SEM image of multi-particulate agglomerates of drug and fines particles adhered to a coarse carrier lactose;

[0031] FIG. 10 is a graphic depicting an example of a peristaltic pump for use in aspects of the invention;

[0032] FIG. 11 is a graphic of encapsulated insulin droplets on lactose powder;

[0033] FIG. 12 is a plot showing particle size distribution (PSD) of a dry powder inhaler (DPI) formulation;

[0034] FIG. 13 is a plot showing residual solvent;

[0035] FIG. 14A is an SEM image of uncoated lactose particle;

[0036] FIGS. 14B and 14C are SEM images of insulin-loaded microparticles attached to the surface of lactose particles

[0037] FIG. 15 is a plot of insulin release from PLGA microparticles over time.DETAILED DESCRIPTION OF THE INVENTION

[0038] Disclosed herein are methods and apparatus for continuous manufacturing (CM) of engineered particulate formulations containing therapeutic agents. In an aspect, the5MEl\57920661.v3Docket: 98121.00410 (#24-068) manufactures, e.g., the engineered particulate formulations, are formulated and configured for pulmonary drug delivery.

[0039] As disclosed herein, electrospray apparatus has been developed for preparation of heterogeneous particles. The resulting particles may be composed of the carrier particles decorated with detachable core (bio-drugs)-sheath (excipients) spherical microparticles, which are suitable for inhaling delivery of bio-drug-containing microparticles.

[0040] The heterogeneous particles formed by the electrospray apparatus and associated method of manufacture may define complex microstructures, wherein the carrier particles are coated or functionalized with microparticles, e.g., spherical microparticles that include core (biodrugs) and sheath (excipients).

[0041] As used herein, the term “microparticle” generally refers to a particle that has a characteristic diameter between 1 micrometer and 1,000 micrometers. An example of a microparticle is a polystyrene bead with a diameter of 10 micrometers as measured by scanning electron microscopy. Similar examples of microparticles include glass beads, metallic microparticles, and ceramic microparticles. As used herein, the term microparticle excludes particles smaller than 1 micrometer in diameter and excludes particles that form bulk granules larger than 1,000 micrometers.

[0042] In some of implementations, dimensions of the small spheres range between approximately 4 to 20 microns, and the large carrier particles have a median size in the range 90-100 microns (measured by SEM or Malvern Mastersizer).

[0043] The methodologies for the figures provided herein were as follows:

[0044] Fluorescence Microscopy: To visualize the distribution of BSA within the microparticles, Fluorescence microscopy (Olympus BX53, Japan) was employed. Before imaging, the microparticles were placed onto a clean glass slide, and images were captured afterwards. Due to the autofhiorescent nature of BSA, no additional additives were required to visualize its distribution within individual microparticles.

[0045] Scanning Electron Microscopy (SEM): The morphology of the microparticles was evaluated using a FEI Nova NanoSEM 450 Scanning Electron Microscope (SEM). Prior to the analysis, each sample was mounted onto a metal stub with double-sided tape to secure the6MEl\57920661.v3Docket: 98121.00410 (#24-068) particles on the metal stub. The mounted metal stubs were then transferred to a sputter coater, where a thin layer of platinum (20 nm) was deposited under vacuum. The purpose of this conductive coating was to minimize charging effects and enhance image clarity. The samples were loaded into the SEM chamber and examined at an accelerating voltage of 4 kV. Micrographs were imaged at various magnifications to accurately capture surface features, particle size, and overall morphology.

[0046] FTIR Spectroscopy: Fourier Transform Infrared (FTIR) spectroscopy was employed to assess the secondary structure of encapsulated proteins and to detect potential structural modifications. These analyses provided critical insights into protein stability. A Thermo Fisher Nicolet Magna 560 spectrometer (Waltham, MA, USA) was used for all measurements. Prior to analysis, each sample was gently placed on the spectrometer’s sampling accessory to ensure uniform contact. The spectrum of each sample was collected from 0 to 4000 cm-1, and the observed peak shifts and new peaks were correlated with potential alterations in protein structure, which provides an understanding of protein stability and its interactions within the PLGA matrix.

[0047] Circular Dichroism (CD) Spectroscopy: Circular Dichroism (CD) spectroscopy was performed using a Jasco J-715 spectropolarimeter (Jasco Global; Tokyo, Japan) in the wavelength range of 200-260 nm to evaluate potential alterations in protein conformation changes during the electrospraying and encapsulation process. Each sample was scanned 16 times at a speed of 100 nm / min. The scan sensitivity was set to the standard 100 mdeg, with a data pitch of 0.1 nm. The measurements were carried out at room temperature, and all samples were prepared under consistent conditions to minimize variability. The CD results provide an assessment of conformational integrity of the protein, which is employed to show if the protein’s functional configuration remained stable throughout the formulation fabrication.

[0048] FIG. 1 is a schematic depiction of a continuous manufacturing (CM) system / apparatus 100. CM system / apparatus 100 includes electrospray equipment that includes pump 102, e.g., a syringe pump, that delivers a feedstock 104 from a supply reservoir 106 to an electrospray nozzle 108. A power supply 109, e.g., a high voltage power supply, establishes a voltage difference between nozzle 108 and a collector 110 in spaced relation thereto.

[0049] A gaseous feed 112 is directed through a gaseous feed conduit 114. The gaseous feed 112 (e.g., air) may be heated and / or cooled within the gaseous feed conduit 114, e.g., through7MEl\57920661.v3Docket: 98121.00410 (#24-068) control of a coil element 116 positioned within conduit 114. The gaseous feed 112 is directed to the region surrounding the electrospray nozzle 108 so as to contribute transmissive force to charged particles 118 delivered from nozzle 108.

[0050] The feedstock 104 is charged as part of the electrospray system and exits the nozzle 108 as charged particles 118. The gaseous feed 112 provides transportive force to the charged particles 118 as the charged particles 118 travel from the nozzle 108 toward a mesh 110 through tower / chamber 120.

[0051] The feedstock 104 to the electrospray nozzle 108 may take various forms. In an embodiment, the feedstock 104 is a drug / excipient emulsion. Examples of drug / excipient emulsions and carrier materials that may be processed in the CM system / apparatus include, but are not limited to, drug: Budesonide, insulin, Doxorubicin, Piroxicam; excipient: PLGA, poly (lactic acid) (PLA), polycaprolactone (PCL), and polyethylene glycol (PEG); carrier: different grades of lactose and mannitol.

[0052] A conveyor belt 122 is in communication with tower / chamber 120. In an aspect, a second feedstock 124 is delivered to the conveyor belt 122 for transport to the tower / chamber 120. The conveyor belt 122 may include drive elements ) / idler roller(s) 126a, 126b and a belt 128. Belt 128 may take the form of a continuous material that wraps around the drive element(s) / idler roller(s) 126.

[0053] The second feedstock 124 may take the form of carrier particles 130 that are delivered from a feed chamber 132 to the top moving surface of belt 128 and transported to the tower / chamber 120 for combination with charged particles 118. In an aspect, the carrier particles 130 may take the form of lactose powder. However, the carrier particles may take various forms to provide the requisite functionality of acting as a carrier for the particles that adhere thereto. As shown in FIG. 1, the carrier particles 130 and the charged particles 118 combine in the tower / chamber 120 to form heterogeneous particles 132 that then exit the tower / chamber 120, e.g., by falling off the end of belt 128 (as belt 128 travels around the drive element / idler roller 126b). A scraper or other mechanism may be provided to contribute to the separation of the heterogeneous particles from the belt.

[0054] A round metal mesh may be used as the collector 110. This mesh collector 110 generally serves two functions: (i) the mesh collector 110 connects to ground to provide the necessary electric field for electrospraying of the charged particles 118; and (ii) the mesh collector 1108MEl\57920661.v3Docket: 98121.00410 (#24-068) allows the composite particles, which are formed when the carrier particles attach with the electrosprayed core-sheath microparticles (bio-drug / excipients), to pass through the mesh and then to be continuously collected downstream.

[0055] The heterogeneous particles 132 may fall through mesh collector 110 for collection therebelow. The heterogeneous particles 132 may be directed / conveyed to a drying cylinder (not picture) or other downstream processing enhance the stability and handling properties thereof.

[0056] The electrospray equipment and conveyer belt may be used for preparation of heterogeneous particles, e.g., an adhesive particle mixture. The particles may be composed of the carrier particles decorated with detachable core (bio-drugs)-sheath (excipients) spherical microparticles, which are suitable for clinical use, e.g., for inhaling delivery of the bio-drug- containing microparticles.

[0057] By controlling the concentration of the carrier, e.g., the lactose powder, and the concentration of the bio-drugs / excipients, the flow rate of the respective feedstocks and gaseous flow, the applied voltage and temperature, and the mesh collector distance, various properties may be controlled. For example: (i) the size of the core-sheath bio-drug / excipients particles can be controlled in the micron and micro scales, respectively; and (ii) heterogeneous pharmaceutical bio-drug particles suitable for pulmonary delivery may be produced.

[0058] The CM system / apparatus 100 depicted in FIG. 1 may be used for generation of pulmonary drug bioformulations. In this example, the syringe pump may be used in the electrospraying system to provide an emulsion flow of bio-drugs and excipients. The drug may be encapsulated in the core surrounded with the excipient solution. To realize a coating by the electrospraying technique, the needle of the syringe may be connected to a high-voltage supply. The high-voltage supply will provide the necessary voltage such that, when the emulsion exits the nozzle, droplets of encapsulated drug are formed in the excipient which then coat the lactose carrier particles carried by the conveyer belt to form heterogeneous particles.

[0059] The CM system / apparatus can be easily scaled up, e.g., through duplication of the modular processes, to increase the total yield. For example, in an aspect, multiple nozzles can be used simultaneously in a larger electrospraying tower with one or more conveyor belts deliver carrier particles for combination with the charged particles.9MEl\57920661.v3Docket: 98121.00410 (#24-068)

[0060] In clinical use, the decorated microparticles on the larger carrier particles may detach from the carrier particles. For example, under sufficient collisional force during deposition (e.g., by inertial impaction, gravitational settling, interception and like mechanisms), the decorated microparticles may detach from the carrier particles in the pulmonary tract.

[0061] In an aspect, the CM system / apparatus 100 of FIG. 1 was used to generate heterogeneous particles. An emulsion of dissolved drug / protein in water (Insulin and bovine serum albumin (BSA)) and a solution of the excipient (PLGA) and dichloromethane (DCM) with Pluronic-F127 as the surfactant agent were prepared. In this implementation, BSA was used as a surrogate formulation for the electrospraying process. In an alternative implementation, insulin was used as the advanced pharmaceutical ingredient (drug). Lactose powder was used as the carrier particle and was delivered to the chamber / tower by a conveyor belt. The emulsion was electrosprayed on the lactose powder that was transported to the tower / chamber by the conveyer belt.

[0062] Human recombinant insulin used in the example was purchased from Sigma-Aldrich (St. Louis, MO, USA). PLGA (with a 50:50 lactide to glycolide ratio, natural viscosity 0.4 dL / g) was purchased from Polysciences (Warrington, PA, USA) and Inhalac 230 lactose powder, employed as a carrier particle (d50: 89.4 pm), was received from Meggle USA (Pawling, NY, USA). PLGA has been widely used as a pharmaceutical excipient for pulmonary drug delivery, Lactose monohydrate, was used to form carrier particles. Insulin was dissolved in DI water (50% gr / ml) and PLGA was dissolved in DCM (10% gr / ml). The volume fraction of oil phase to water phase was set to 50: 1 (ml / ml) to make a water / oil emulsion. Then, the insulin solution was dispersed into the organic phase containing Pluronic Fl 27 (10% gr / ml) by probe sonicating for 20 s at 20% amplitude and 20 kHz.

[0063] The size of the core-sheath droplets generated by electrospray can be altered based on operating parameters, e.g., flow rate and / or voltage. In an implementation, the emulsion was electrosprayed with 12 KV voltage and 5 ml / hr flow rate. The resulting core- sheath particles decorated the carrier lactose particles, and the active drug core particle remains encapsulated by the excipient sheath layer and is physically stable.

[0064] Distribution of encapsulated BSA inside the PLGA was evaluated with a fluorescence microscope (see FIG. 2). Examination showed uniform distribution and unisize droplets.10MEl\57920661.v3Docket: 98121.00410 (#24-068)

[0065] Morphology of the encapsulated insulin inside the PLGA was checked as well as adhesion of the droplets to the lactose carrier using SEM (see FIG. 3) which represents good adhesion of the droplets to the carrier lactose powder and promising morphology of the coresheath particles.

[0066] Finally, the preservation of secondary structure of the insulin after the electrospray was tested with FTIR, which shows no change of insulin peaks before and after the electrospray, thereby assuring biological activity of the insulin (see FIG. 4 and FIG. 5). Two peaks of insulin Amide I Band at 1645 cm-1 (C=O stretching vibrations) and Amide II Band at 1537 cm-1 (N- H bending and C-N stretching) are repeated in both graphs, which establishes no change of the structure and stability of the insulin.

[0067] The current approaches that are being used to develop the formulation of dry powder inhalers are spray drying and mechanical blending of particles.

[0068] In spray drying, a mixture (suspension or solution) of drugs and excipients is sprayed to produce the dry powders formulations. These formulations are designed to disperse effectively upon aerosolization, containing a substantial number of particles smaller than a micrometer. In this method, coating the drug particle with an excipient is the focus. Excipients are commonly incorporated into dry powder inhaler (DPI) formulations for improving the physical and chemical stability of the active pharmaceutical ingredient (API), modification of pharmacokinetics and / or dynamics of the API, adjusting the bioavailability and solubility of APIs and preventing dissociation and aggregation. Due to the excessive amount of excipient used in the mixture, the drug is typically encapsulated by excipients. The small micron-size of the final drug / excipient particles from spray drying may result in poor delivery efficiency.

[0069] FIG 8 provides a representative SEM image of mono bevacizumab (BEV).

[0070] In blending, once the drug and carrier have been prepared individually to their desired states, they are then combined during the blending process. Drug and carrier powders are mixed until reaching a homogeneous concentration of drug on all the particles. The carrier serves several functions, including: (1) enhancing the flowability of drug particles to facilitate filling the DPI, (2) promoting dispersion of drug particles during emission, and (3) ensuring the drug reaches the deep lung. The success of blending method heavily depends on the right “chemistry” between the drug particles and the carrier particles to allow drug particles to be adhered to the carrier particles.11MEl\57920661.v3Docket: 98121.00410 (#24-068)

[0071] FIG. 9 provides an image of SEM multiparticulate agglomerates of drug and fines particles adhered to the coarse carrier lactose.

[0072] The methods / apparatus leverage both excipient and carriers to provide a DPI formulation that incorporates both carrier and excipient components to enhance drug delivery efficiency while maintaining drug stability. The methods / apparatus provide an end-to-end CM process design that effectively addresses contamination / sterility issues and requirements.

[0073] In an aspect, the apparatus operates in a continuous manner, e.g., by incorporating a peristaltic pump of the type shown in FIG. 10 to continuously deliver feedstock to the nozzle.

[0074] In an aspect, the electrospray system is positioned within sterile enclosure(s) or chamber(s). The electrospray components may employ an autoclavable container, tubing, and / or nozzle, thereby enhancing ease of sterilization using common sterilization techniques, such as autoclaving. Also, the system / method is compatible with cleanroom environments and adheres to cleanroom standards to minimize the risk of contamination.

[0075] In an aspect, an example of a clinically relevant concentration / dosage is provided. For example, Mannkind Corporation (Bedford, MA, USA) offers an insulin product commercially (Afrezza® insulin) in an 8-unit cartridge which contains 0.7 mg of insulin, and 4 units are needed per meal, so the dose required per meal is 0.35 mg. In this example, if all the lactose particles are decorated (see FIG. 11), about 1 gram of material is needed of DPI to reach a 0.35 mg insulin dose. However, this weight can be significantly reduced by increasing the insulin / excipient coverage on the lactose carrier particles, which can be facilely realized by changing the electrospraying parameters and / or belt parameters. In FIG. 11, the emulsion was sprayed for 1 min at the rate of 5 ml / hr. With an increased flow rate or residence time, the process can be used to easily coat more drug to the carrier.

[0076] Generally, the amount of waste is related to how the carrier particles are placed on the belt. For instance, a hopper may be used to mount carrier particles on the belt. The hopper(s) may be adjusted so to deliver a mono layer of carrier particles at an efficient rate. Furthermore, fine-tuning of the hopper(s) to precisely position the carrier onto the belt, even with minimal clearance, is desirable. Hoppers can integrate adjustable elements, like conveyor belt speed, hopper angle, or gate openings, to regulate carrier placement. Additionally, employing sensors, such as proximity sensors or vision systems, enables hopper operation to be responsive to real-12MEl\57920661.v3Docket: 98121.00410 (#24-068) time data collected with respect to relevant parameters, e.g., the carrier's position, facilitating precise adjustments for accurate placement.

[0077] In terms of overlapping of the droplets, waste generation may depend on residence time of the carrier particles and the flow rate of the electrospraying process, both of which can be optimized to avoid overlapping.

[0078] A fundamental difference between an ordered and a random mixture is the nature of forces which limit the freedom of migration for the fine constituent particles. Due to the extremely small mass of a single drug particle relative to the neighboring carrier particles, gravity has little influence in comparison to the forces exerted by the neighboring particles, causing the drug particles to aggregate with each other (cohesion) and excipient particles (adhesion) present in the formulation. Achieving an ordered mixture is beneficial for DPI formulations because it ensures uniform dispersion of the active pharmaceutical ingredient and other excipients, leading to consistent dosing and efficient delivery to the lungs. In addition, an ordered mixture ensures that particles are appropriately sized and distributed for optimal aerosolization, maximizing lung deposition and drug absorption. An ordered mixture formulation is more likely to maintain stability over time, minimizing degradation of the API and other components.

[0079] In DPI formulations, analysis / understanding of the particle size distribution (PSD) is generally needed because it directly affects where drug particles settle within the lungs, thereby significantly impacting the delivery effectiveness. Maintaining a controlled particle size distribution ensures that the majority of the drug reaches the desired target areas in the respiratory tract, optimizing therapeutic purposes while minimizing potential side effects resulting from incorrect deposition in the upper airways. Precise control of particle size distribution can be beneficial.

[0080] In many DPI formulations, carrier particles such as lactose are incorporated to enhance the dispersion of the drug particles adhered to their surface. Carrier particle size may affect DPI formulation performance. For example, by increasing carrier particle size, improved aerosolization properties may be exhibited for a DPI formulation. Moreover, carriers with larger size have higher surface area which enables them to accommodate greater amounts of drug particles and have increased deposition capacity.13MEl\57920661.v3Docket: 98121.00410 (#24-068)

[0081] FIG. 12 shows a plot of particle size distribution for a bulk fabricated DPI formulation. The formulation has a moderately narrow particle size range with a d50 of 95.9 pm, which is beneficial for the aerodynamic behavior of the DPI formulation. The PSD analysis indicates zero presence of larger aggregates larger than 1000 pm. Overall, this PSD result indicates a well-designed carrier-based DPI formulation that balances flowability, dispersibility, and potential lung deposition. The particle size distribution of the microparticles was analyzed using a Mastersizer 2000E along with a Scirocco unit (Malvern Instruments, Worcestershire, United Kingdom), which is engineered for accurate measurement of dry powder particle size. This analysis was conducted under an air pressure of 4.0 bar to achieve uniform dispersion and consistent microparticle sizing.

[0082] Control of particle size distribution is beneficial because it directly impacts the flowability properties and deposition efficiency of the microparticles within the respiratory tract and influences the overall effectiveness of the DPI formulation.

[0083] After microparticle fabrication, the amount of residual solvent in the electrosprayed microparticles may be minimized, especially for biomedical and drug delivery applications. Elimination of remaining solvent during the encapsulation process is beneficial, both to prevent potential toxicity in patients and to preserve the therapeutic purpose of the encapsulated API. Residual solvent can interfere with API properties, such as stability, functionality, and drug release behavior. Residual solvent may also result in non-compliance with regulatory limits for solvent content in pharmaceutical products. Since the solvent itself offers no therapeutic value, reducing its presence to the lowest possible level is beneficial to ensure both safety and quality.

[0084] With reference to FIG. 13, a plot of residual solvent in the microparticles after electrospraying is provided as compared to the standard sample. Residual solvent levels were obtained via GC-MS, and illustrate the detected solvent peaks and their relative intensities. More particularly, the residual DCM within the microparticles was assessed using gas chromatography-mass spectroscopy (GC-MS). The GC-MS analysis was performed using the Agilent 7200 GC QTOF (Agilent Technologies, Santa Clara, CA, USA), which was equipped with a robotic sampler system. The separation was conducted on an HP 5MS column (30 m x 0.25 mm x 0.25 micro m). The oven temperature of GC analysis started from 45 °C per min (hold of 2 min) with a 15°C per min oven ramp to 325 °C (hold of 3 min), and a 50°C per min oven ramp to 325 °C for a purge. The time for reaching equilibration was 0.2 min for each14MEl\57920661.v3Docket: 98121.00410 (#24-068) cycle, and each cycle took 15.2 minutes. For sample preparation, 50 mg of the formulation was added, suspended in 1 mL ethyl acetate and was diluted with methanol. The helium carrier gas was set to a constant 1.2 mL per min flow with injection of 1 pL of the sample, and a splitless injection mode was applied. The purge flow to split vent rate was 50 mL per min at 1 min. Also, the collision gas was N2 and the collision flow was 1.5 mL per min, and the pressure was 9.46 psi. The vial pressure was 10.0 psi. Helium gas was used as a quench and auxiliary gas, and it was split in a ratio of 100 times for running the samples. The scanned m / z range was 35- 400 with the acquisition rate of 10 spectra per second. The empty vial blanks were interspersed with the samples to assess the background signal. A calibration curve, created based on the ratio of DCM standards to the ethyl acetate internal standard, was employed to quantify the amount of DCM present in the formulation.

[0085] The plot of FIG. 13 confirms effective solvent removal. The residual solvent level is well below 100 ppm, which is significantly lower than the USP-regulated limit for DCM of 600 ppm. To quantify the residual solvent amount, a calibration curve was generated by standard samples with different concentrations of DCM. Based on the trending line, the residual solvent of the formulation was approximately 55.89 ppm.

[0086] In an aspect, the apparatus / methods provide the ability to readily change / optimize droplet size and coverage. As an example, a formulation was sonicated for 60s and then electrosprayed with 1 ml / hr flow rate for 20 minutes. Dry lactose particles were then continuously fed under the electrospray needle and were coated by the droplets produced from electrospray. SEM analysis was conducted to visualize the presence and distribution of microparticles on the surface of lactose particles.

[0087] As shown in the SEM image of FIG. 14A (50 pm magnification), the uncoated lactose particle forms a tomahawk- shaped and includes surface imperfections. As shown in the SEM images of FIGS. 14B and 14C, insulin-loaded microparticles attached to the surface of lactose particles (50 m magnification) produced according to an implementation hereof. The particles are uniformly spherical, and the droplets particle size was approximately 4.2 pm based on the SEM images. Comparing to the SEM image in FIG. 3, the number of particles that coated the lactose surface is increased significantly, and size of the droplets also decreased from approximately 20 pm to 4.2 pm. The encapsulated insulin coats the lactose carrier particles due to the adhesive characteristics of PLGA microparticles.15MEl\57920661.v3Docket: 98121.00410 (#24-068)

[0088] In an aspect, DPI formulations are thus produced that incorporate both a carrier and encapsulation of API with an excipient. By combining these two functional additives, the formulation has enhances aerosolization performance, improves powder flow properties, and promotes efficient deposition within the respiratory tract, thereby providing a sustained drug release of the formulation.

[0089] In vitro protein release and encapsulation efficiency are achieved with the particles produced herein. In an aspect, Table 1 shows encapsulation efficiency of a DPI formulation. As indicated, the insulin-loaded microparticles achieved 78.16% encapsulation efficiency, which indicates that the majority of the protein was confined inside the PLGA matrix with low variation.TABLE 1Parameter ValueEncapsulation Efficiency (%) 78.16 ± 3.31Particle d50 (pm) 95.9 + 2.76

[0090] As shown in FIG. 15, the release profile of insulin from PLGA is shown over a 3-day period. The release profile indicates a biphasic protein release pattern. In the first hour, a burst phase occurred. Approximately 60% of insulin was released within the first 5 hours. This rapid release can be due to the dissolution of insulin molecules that were located near the surface of the PLGA before the water diffuses and penetrates out of the matrix, causing degradation. After that initial period, release slows but continues steadily, reaching approximately 72 % cumulative release over the next 7 hours. Beyond this point, the curve does not show any significant change; however, a slight secondary uptick in release brings the total to about 75 % by 72 hours. In this more sustained phase, PLGA-controlled diffusion and partial polymer degradation govern the release rate of insulin, allowing for a more controlled and gradual protein release. In an aspect, a high encapsulation efficiency is shown and, while the immediate burst can provide a rapid initial dose of insulin, the extended-release phase is significant for maintaining stable therapeutic levels of insulin over longer periods.

[0091] For in vitro protein release of the microparticles, a 400 series UV-Vis spectrophotometer (SI Photonics, Tucson, AZ) was used. 100.0 mg of the microparticles were suspended in 20 mL PBS (PH 7.4) containing 0. 1 (w / v) % Tween 80. During the analysis, each16MEl\57920661.v3Docket: 98121.00410 (#24-068) sample was incubated at 37°C and shaken at 100 rpm. At different time intervals, the UV absorption of protein in solution was measured to generate the release profile of the protein from the PLGA matrix, and a calibration curve consisting of pure protein samples was used to quantify the amount of protein released. For encapsulation efficiency, 150 mg of microparticles were suspended in DCM, and after dissolution of PLGA, 10 mL PBS containing 0.1 (w / v) % Tween 80 was added to them. Tubes were vortexed for 5 min and then centrifuged for 20 min at 9000 RPM. The amount of insulin in the separated water phase was then measured using the UV-Vis and quantified using the calibration curve prepared using native protein samples.

[0092] In an aspect, a computer program product is stored on non-transitory machine-readable media, the computer program product including machine-readable instructions for controlling production of manufactured particles by operation of an electrospraying apparatus that includes a conveyor system for delivery of carrier particles. The computer program product may communicate over a network that includes at least one of a controller with computing capabilities. The computer program product may control one or more aspects of particle manufacture, and may include at least one of the following: (i) instructions for controlling a feed rate of particles to the electrospraying apparatus; (ii) instructions for controlling residence time of charged particles within a tower or chamber associated with the electrospraying apparatus, (iii) instructions for controlling feed of carrier particles with the conveyor system, (iv) instructions for controlling temperature within the tower or chamber, and (v) instructions for controlling the voltage delivered to the electrospraying apparatus.

[0093] All statements herein reciting principles, aspects, and embodiments of the disclosure, as well as specific examples thereof, are intended to encompass both structural and functional equivalents thereof. Additionally, it is intended that such equivalents include both currently known equivalents as well as equivalents developed in the future, i.e., any elements developed that perform the same function, regardless of structure.

[0094] Various other components may be included and called upon for providing for aspects of the teachings herein. For example, additional materials, combinations of materials and / or omission of materials may be used to provide for added embodiments that are within the scope of the teachings herein. Adequacy of any particular element for practice of the teachings herein is to be judged from the perspective of a designer, manufacturer, seller, user, system operator or other similarly interested party, and such limitations are to be perceived according to the standards of the interested party.17MEl\57920661.v3Docket: 98121.00410 (#24-068)

[0095] In the disclosure hereof any element expressed as a means for performing a specified function is intended to encompass any way of performing that function including, for example, a) a combination of circuit elements and associated hardware which perform that function or b) software in any form, including, therefore, firmware, microcode or the like as set forth herein, combined with appropriate circuitry for executing that software to perform the function. Applicants thus regard any means which can provide those functionalities as equivalent to those shown herein. No functional language used in claims appended herein is to be construed as invoking 35 U.S.C. § 112(f) interpretations as “means-plus-function” language unless specifically expressed as such by use of the words “means for” or “steps for” within the respective claim.

[0096] When introducing elements of the present invention or the embodiment(s) thereof, the articles “a,” “an,” and “the” are intended to mean that there are one or more of the elements. Similarly, the adjective “another,” when used to introduce an element, is intended to mean one or more elements. The terms “including” and “having” are intended to be inclusive such that there may be additional elements other than the listed elements. The term “exemplary” is not intended to be construed as a superlative example but merely one of many possible examples.18MEl\57920661.v3

Claims

Docket: 98121.00410 (#24-068)CLAIMSWhat is claimed is:

1. A method for manufacturing particles, comprising: a. electrospraying charged particles into a tower or chamber; b. combining the electrosprayed charged particles with carrier particles conveyed to the tower or chamber to form heterogeneous particles; and c. recovering the heterogeneous particles from the tower or chamber.

2. The method of claim 1 , wherein the electrospraying of the charged particles comprises a nozzle.

3. The method of claim 2, further comprising delivering gaseous feed to the tower or chamber in proximity to the nozzle.

4. The method of claim 3, further comprising controlling the temperature of the gaseous feed.

5. The method of claim 2, wherein the electrospraying of the charged particles comprises a voltage source and a collector positioned below the nozzle.

6. The method of claim 5, wherein the collector comprises a wire mesh.

7. The method of claim 2, further comprising delivering a drug and excipient emulsion to the nozzle.

8. The method of claim 7, wherein the drug comprises a bio-drug.

9. The method of claim 7, wherein the excipient comprises a sheath.

10. The method of claim 1, wherein the carrier particles are delivered to the tower or chamber by a conveyor belt.

11. The method of claim 1 , wherein the carrier particles are delivered to a conveyor belt from a hopper.

12. A microencapsulated drug manufactured by the method of claim 1.

13. The microencapsulated drug of claim 12, comprising carrier particles decorated with detachable core and sheath microparticles.19MEl\57920661.v3Docket: 98121.00410 (#24-068)14. The microencapsulated drug of claim 13, wherein the carrier particles decorated with detachable core and sheath microparticles is configured and adapted for inhaling delivery thereof.

15. The microencapsulated drug of claim 13, wherein the carrier particles are coated or functionalized with the detachable core and sheath microparticles.

16. An apparatus for manufacture of particles, comprising: a. an electrospray device that includes a nozzle and a collector, and that is configured to deliver charged particles to a tower or chamber; and b. a conveyor belt configured to deliver carrier particles to the tower or chamber for combination with the charged particles.

17. The apparatus of claim 16, further comprising a gaseous feed source configured to deliver a gaseous feed to the tower or chamber in the region of the nozzle.

18. The apparatus of claim 16, further comprising a hopper configured and positioned to deliver the carrier particles to the conveyor belt.

19. The apparatus of claim 16, wherein the collector comprises a wire mesh.

20. The apparatus of claim 16, wherein the conveyor belt comprises at least one drive element or idler roller.

21. The apparatus of claim 16, further comprising a computer program product stored on non-transitory machine-readable media, the computer program product comprising machine-readable instructions for controlling production of manufactured particles by controlling operation of at least one of the electrospray device and the conveyor belt.

22. A computer program product stored on non-transitory machine-readable media, the computer program product comprising machine-readable instructions for controlling production of manufactured particles by operation of an electrospraying apparatus that includes a conveyor system for delivery of carrier particles.

23. The computer program product of claim 22, wherein the controlling comprises communicating over a network comprising a controller with computing capabilities.20MEl\57920661.v3Docket: 98121.00410 (#24-068)24. The computer program product of claim 22, wherein the controlling comprises at least one of the following: (i) instructions for controlling a feed rate of particles to the electrospraying apparatus; (ii) instructions for controlling residence time of charged particles within a tower or chamber associated with the electrospraying apparatus, (iii) instructions for controlling feed of carrier particles with the conveyor system, (iv) instructions for controlling temperature within the tower or chamber, and (v) instructions for controlling the voltage delivered to the electrospraying apparatus.21MEl\57920661.v3

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