PEG Capsule Sustained Drug Delivery via Porous Membrane
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Solution Overview
Problem
Current drug delivery systems for treating eye diseases are invasive, often require complex surgeries, and have limitations in achieving stable, long-term drug release due to issues like initial drug bursts, short release periods, and low bioavailability at target sites, leading to reduced therapeutic efficacy and increased risks of infection and side effects.
Innovation Solution
A compact, stepwise slow-release transscleral drug delivery system using a PEG capsule with a porous PEG sheet, where collagen is impregnated with a therapeutic drug and packed in a PEG pellet or gel form, allowing controlled drug release through a porous PEG sheet, enabling sustained delivery to the choroid and retina for extended periods without initial bursts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If a drug is directly injected into the vitreous body, then the drug can be delivered to the target site, but the drug is dispersed and metabolized immediately, resulting in low transfer amount to the target site
Solution Approach 1:
The drug is pre-loaded into the PEG capsule implant before implantation into the sclera. The implant is prepared in advance with the drug enclosed in a controlled-release matrix, preventing immediate dispersion and metabolism upon administration. This preliminary encapsulation ensures the drug remains contained and releases gradually over time.
Solution Approach 2:
A porous PEG sheet acts as a flexible membrane enclosing the drug-containing PEG pellet or gel. This thin film structure allows controlled diffusion of the drug through its porous architecture while maintaining containment, preventing immediate dispersion into the vitreous body. The flexible shell enables sustained release over extended periods.
2Duration of action of stationary object
If a non-degradable DDS implant is used for long-term drug delivery, then the drug release period can be extended, but reoperation is required to remove the implant when causing side effects, increasing infection risk and patient burden
Solution Approach 1:
The implant utilizes biodegradable PEG materials that change their physical and chemical properties over time through controlled degradation. The PEG polymer gradually breaks down into smaller molecules that are naturally excreted by the body. This parameter change from intact polymer to degraded fragments allows the implant to be temporarily retained for sustained drug release (up to 5 years or more) and then automatically eliminated without surgical intervention, reducing infection risk and patient burden.
3Quantity of substance
If a high concentration of drug is injected to overcome rapid metabolism, then the target site can receive sufficient drug, but side effects on normal intraocular tissue are increased
Solution Approach 1:
The drug is delivered with high local concentration precisely at the target site through controlled diffusion from the implant, while the surrounding intraocular tissues are protected from excessive drug exposure. The porous PEG sheet and biodegradable matrix create a localized release zone that maintains therapeutic concentrations at the retina or choroid without causing systemic or widespread ocular toxicity. The degradation products are naturally metabolized and excreted, further reducing harmful effects.
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 system provides a stable, long-term drug release for up to 5 years or more, minimizing side effects and surgical risks, with the ability to deliver multiple drugs at different speeds, enhancing therapeutic efficacy and patient comfort.
Implementation Method 1
the internal drug is slowly released through the porous PEG sheet
Implementation Method 2
because the main body is made of a biodegradable polymer, the implant can be eliminated without undergoing surgery when it has become unnecessary or when causing side effects
Data Source
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AI summary
Disclosed is a drug delivery system for delivering a drug at a sustained constant rate for a long period, which can be transplanted into an affected part safely and in a simple manner and can deliver a drug to the affected part for a long period. Specifically disclosed is a sustained drag delivery system in which an implant is implanted into a body, wherein the implant is a PEG capsule comprising a box-shaped PEG and a porous PEG sheet, and wherein the box-shaped PEG has, encapsulated therein, a solution of a therapeutic drug, a collagen impregnated with the therapeutic drug, or a PEG pellet including the collagen impregnated with the therapeutic drug, and the PEG capsule has such a structure that the box-shaped PEG is covered with the porous PEG sheet so that the drug contained in the PEG capsule can be released through the porous PEG sheet in a sustained manner.