Multilayer CMC Hydrogel Carrier for Sustained Eye Drop Delivery
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Solution Overview
Problem
Current eye drop formulations have low drug absorption rates due to rapid washing out by tears, leading to frequent administration needs and potential side effects, and existing technologies struggle with maintaining drug efficacy and sterility during sterilization processes.
Innovation Solution
A carrier composition for eye drops featuring a multilayer shell structure with carboxymethyl cellulose-based hydrogels, allowing sustained drug release and maintaining efficacy for extended periods, while also enabling easy sterilization without filter-induced changes in drug or excipient content.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional eye drop formulations are used, then the drug can be administered easily, but the drug absorption rate is very low (5% or less) due to rapid washing out by tears and eye blinking
Solution Approach 1:
The patent uses a hydrogel carrier that forms a flexible, mucoadhesive film on the ocular surface. This hydrogel shell retains the drug at the application site, preventing rapid washing out by tears and allowing sustained release over 24 hours or longer, thereby dramatically improving drug absorption rate from 5% or less to much higher levels.
Solution Approach 2:
The patent employs a composite hydrogel system combining multiple polymers (e.g., carbomer, chondroitin sulfate, hyaluronic acid) to create a carrier with enhanced mucoadhesive properties and controlled drug release characteristics. This composite material structure ensures both retention on the ocular surface and sustained drug delivery, resolving the contradiction between easy administration and low absorption.
2Reliability
If eye drops are administered frequently (3 to 6 times a day for 1 month) to maintain efficacy, then the therapeutic effect is maintained, but patient convenience is reduced and side effects from frequent administration increase
Solution Approach 1:
The hydrogel carrier provides continuous drug release over an extended period (24 hours or more) through sustained diffusion and erosion mechanisms. This continuous action maintains therapeutic efficacy throughout the day, allowing administration only once or twice daily instead of 3-6 times, thereby improving patient convenience while maintaining reliability of therapeutic effect.
Solution Approach 2:
The patent uses an excessive amount of mucoadhesive polymer in the hydrogel carrier to ensure prolonged residence time on the ocular surface. This excessive adhesion ensures the carrier remains in place for 24 hours or more, providing sustained drug release and eliminating the need for frequent re-administration, thus resolving the contradiction between maintaining therapeutic effect and reducing administration frequency.
3Reliability
If high-temperature sterilization is used to maintain sterility, then the composition remains sterile, but steroid-based drugs undergo denaturation
Solution Approach 1:
The patent changes the sterilization parameter from high temperature to low temperature (4°C refrigeration) combined with aseptic manufacturing techniques. This parameter change allows sterilization and sterility maintenance without exposing temperature-sensitive steroid-based drugs to denaturing high temperatures, thereby preserving both sterility and drug stability.
Solution Approach 2:
The patent introduces an intermediary approach by using aseptic manufacturing processes and cold storage (4°C refrigeration) as alternative sterilization methods. This intermediary technique achieves sterility maintenance without directly applying high-temperature heat to the drug, thus preventing denaturation while ensuring sterility through indirect means.
4Reliability
If filter sterilization is used, then sterility can be achieved, but severe changes occur in the contents of excipient and active ingredient
Solution Approach 1:
The patent changes the sterilization parameter from mechanical filtration to low-temperature refrigeration (4°C) combined with aseptic manufacturing. This parameter change achieves sterility without the physical stress of filtration that causes severe changes in excipient and active ingredient content, thereby maintaining both sterility and compositional stability.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The carrier composition effectively prolongs drug duration, reduces frequency of administration, maintains efficacy for up to 24 hours with a single application, and ensures sterility without altering the drug or excipient content, enhancing patient convenience and reducing toxicity.
Implementation Method 1
a carrier composition for eye drops, which allows a substance to be delivered to stay in the anterior segment of an eye for a long time and slowly releases the substance to be delivered
Implementation Method 2
the carrier includes a multilayer shell in a region ranging from the center to the surface of the carrier, the multilayer shell includes a core located in the center of the carrier and including a carboxymethyl cellulose (CMC)-based hydrogel
Implementation Method 3
the first shell located on the surface of the core and including a CMC-based hydrogel having a degree of substitution of 0.8, a second shell located on the surface of the first shell and including a CMC-based hydrogel having a degree of substitution of 0.6
Data Source
AI summary
The present disclosure provides a carrier composition for eye drops in which a substance to be delivered is loaded in a carrier, wherein the substance to be delivered includes one or more selected from the group consisting of an anti-inflammatory agent, a glaucoma treatment agent, a calcium channel blocker (CCB), an NMDA-receptor blocker, an antioxidant, a nitric oxide synthase inhibitor, a heat shock protein (HSP), a cystinosis treatment agent, and an antibiotic, the carrier has a spherical shape, the carrier includes a multilayer shell in a region ranging from the center to the surface of the carrier, the multilayer shell includes a core located in the center of the carrier and including a carboxymethyl cellulose (CMC)-based hydrogel having a degree of substitution (D.S.) of 0.9, a first shell located on the surface of the core and including a CMC-based hydrogel having a degree of substitution of 0.8, a second shell located on the surface of the first shell and including a CMC-based hydrogel having a degree of substitution of 0.6, and a third shell including a CMC-based hydrogel having a degree of substitution of 0.65, and the multilayer shell includes the core having a radius equal to 25% of the radial length of the carrier, the first shell having a thickness equal to 20% of the radial length, the second shell having a thickness equal to 40% of the radial length, and the third shell having a thickness equal to 15% of the radial length, and a pharmaceutical composition including the same.