Lipid-Based Depot Formulation for Sustained Release
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Solution Overview
Problem
Existing lipid-based depot formulations for bioactive agents face challenges such as burst/lag release profiles, irritation from polymer degradation, complex manufacturing, and limited resistance to chemical and enzymatic degradation, making them unsuitable for long-term or protective applications.
Innovation Solution
A pre-formulation comprising a low viscosity mixture of diacyl glycerol, phospholipids with high phosphatidyl ethanolamine content, and a biocompatible organic solvent forms a non-lamellar liquid crystalline phase upon contact with aqueous fluids, providing improved mechanical and chemical resistance, controlled release, and bioadhesion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of moving object
If polymer-based depot systems are used for sustained release, then the duration of action is extended, but local irritation occurs due to lactic and glycolic acid degradation products
Solution Approach 1:
The patent changes the chemical composition parameters from polymer-based (PLA/PLGA) to lipid-based components (diacyl glycerol, phospholipids, tocopherol), fundamentally altering the degradation pathway to eliminate acidic degradation products while maintaining sustained release capability over periods of days to weeks
Solution Approach 2:
The invention uses a composite lipid system combining diacyl glycerol, phospholipids with high phosphatidyl ethanolamine content, and tocopherol, which work synergistically to provide both sustained release and reduced local irritation compared to single-component polymer systems
2Manufacturing precision
If liquid crystalline phases are used in lipid-based formulations, then controlled release is improved, but resistance to chemical and enzymatic degradation is reduced
Solution Approach 1:
The patent applies different structural characteristics to different aspects of the formulation: the phospholipid component forms liquid crystalline phases for controlled release, while the diacyl glycerol and tocopherol provide chemical stability and degradation resistance, creating a multi-functional system where each component serves a specific quality requirement
Solution Approach 2:
The formulation includes tocopherol (vitamin E) as an antioxidant that provides beforehand protection against oxidative degradation, and the specific phospholipid composition is selected to resist enzymatic degradation, cushioning the formulation against chemical and biological degradation before administration
3Ease of operation
If pre-polymer solutions are used for depot injection, then ease of administration is improved, but burst/lag release profile occurs causing concentration fluctuations
Solution Approach 1:
The patent changes the physical state parameter from pre-polymer solution requiring reconstitution to a ready-to-inject liquid or semi-liquid lipid formulation, eliminating the burst/lag profile by creating a homogeneous system that releases drug steadily without initial overload followed by depletion
Solution Approach 2:
The lipid-based formulation is self-contained and ready for direct injection without requiring reconstitution with solvents or additional preparation steps, making it self-sufficient and eliminating the complex preparation procedure associated with polymer pre-polymers
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 formulation achieves a sustained and controlled release of bioactive agents with reduced irritation and increased longevity, suitable for long-term parenteral and non-parenteral administration, including per-oral applications, with enhanced resistance to degradation and bioadhesive properties.
Implementation Method 1
comprising lipids that upon exposure to water or aqueous media, such as body fluids, spontaneously undergo at least one phase transition, thereby forming a controlled release matrix
Implementation Method 2
forms a non-lamellar liquid crystalline phase upon contact with aqueous fluids
Implementation Method 3
forms a non-lamellar liquid crystalline phase upon contact with aqueous fluids
Data Source
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AI summary
The present invention relates to compositions forming a low viscosity mixture of: a. at least one diacyl glycerol and/or at least one tocopherol; b. at least one phospholipid component comprising phospholipids having i. polar head groups comprising more than 50% phosphatidyl ethanolamine, and ii. two acyl chains each independently having 16 to 20 carbons wherein at least one acyl chain has at least one unsaturation in the carbon chain, and there are no more than four unsaturations over two carbon chains; c. at least one biocompatible, oxygen containing, low viscosity organic solvent; wherein optionally at least one bioactive agent is dissolved or dispersed in the low viscosity mixture; and wherein the pre-formulation forms, or is capable of forming, at least one non-lamellar liquid crystalline phase structure upon contact with an aqueous fluid. The invention further relates to methods of treatment comprising administration of such compositions, and to pre-filled administration devices and kits containing the formulations.