Lipid Pre-Concentrate Liquid Crystal Phase Transition for Sustained Release

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Solution Overview

Problem

Conventional sustained release formulations using PLGA induce inflammation and have low biodegradability, leading to prolonged presence of drug delivery particles in the body, causing discomfort and reduced patient compliance.

Innovation Solution

A lipid pre-concentrate comprising sorbitan unsaturated fatty acid ester with multiple hydroxyl groups, phospholipids, and a liquid crystal hardener forms a liquid crystal phase upon exposure to aqueous fluids, enhancing drug release and biodegradability, thus providing a safe and effective sustained release mechanism.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Duration of action of moving object

If PLGA solid particles are used for sustained release, then the effective plasma concentration can be maintained for a specific period, but inflammation and pain occur at the injection site due to degradation products

Engineering Contradiction:
Improvesustained release periodVSAvoidinflammation and pain
Core Design Contradiction:
Duration of action of moving objectVSObject-affected harmful factors

Solution Approach 1:

The invention changes the material parameters from PLGA polymer to specific lipid components (sorbitan unsaturated fatty acid ester, phospholipid, and liquid crystal hardener), fundamentally altering the degradation pathway from acidic monomers to biocompatible lipid metabolism products, thereby eliminating inflammation while maintaining sustained release capability

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention uses a composite lipid system comprising three specific components (sorbitan unsaturated fatty acid ester, phospholipid, and liquid crystal hardener) that work synergistically to form liquid crystal structures, providing both sustained release functionality and biocompatibility, avoiding the harmful effects of single-material PLGA degradation

Inventive Principle:
Principle #40Composite materials

2Duration of action of stationary object

If PLGA solid particles of 10-100 micrometers are injected for sustained release, then drug release is achieved over several months, but patient compliance decreases due to pain and inflammation

Engineering Contradiction:
Improvedrug release durationVSAvoidpatient compliance
Core Design Contradiction:
Duration of action of stationary objectVSEase of operation

Solution Approach 1:

The invention changes the physical state parameter from solid particles to liquid crystal phase, allowing the formulation to be injected in liquid form and then transition to gel-like structure in vivo, eliminating injection pain while maintaining prolonged drug release through the liquid crystal-to-gel transition mechanism

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention converts the potential harm of solid particle injection (pain and inflammation) into benefit by using liquid crystal hardeners that enable phase transition from liquid (injectable) to gel (sustained release matrix), turning what would be a harmful solid particle injection into a beneficial painless liquid injection with controlled gel formation

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

3Ease of manufacture

If conventional organic solvents are used in pre-formulations, then low viscosity and ease of injection are achieved, but drug activity decreases and safety concerns arise

Engineering Contradiction:
Improveformulation preparationVSAvoiddrug activity and safety
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The invention changes the solvent system from conventional organic solvents to a water-based liquid crystal system, eliminating solvent-induced drug deactivation while maintaining low viscosity through the liquid crystal phase and ensuring safety through biocompatible lipid components that metabolize naturally in the body

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The liquid crystal hardener acts as an intermediary component that enables the formulation to exist as a low-viscosity liquid during preparation and injection, then transitions to a gel-like structure in vivo, mediating between the requirements for ease of administration and drug stability/safety without requiring harmful organic solvents

Inventive Principle:
Principle #24Intermediary (Mediator)

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 lipid pre-concentrate ensures prolonged drug release without pain or inflammation, improving patient compliance and biodegradability, maintaining effective plasma concentrations for extended periods while minimizing side effects.

Implementation Method 1

a lipid pre-concentrate comprising a) a sorbitan unsaturated fatty acid ester having a polar head with at least two or more -OH (hydroxyl) groups; b) a phospholipid; and c) a liquid crystal hardener... exists as a liquid state in the absence of aqueous fluid and transits into a gel-like liquid crystal upon exposure to aqueous fluid

Methodology Applied
Scientific EffectLiquid crystal phase transition: Liquid Crystals

Data Source

PatentEP2750667B1Sustained-release lipid pre-concentrate of pharmacologically active substance and pharmaceutical composition comprising the same
Publication Date: 2017.12.06 CHONG KUN DANG PHARMACEUTICAL CORP
  • EP2750667B1 patent drawingFigure 1~3
  • EP2750667B1 patent drawingFigure 4~5
  • EP2750667B1 patent drawing

AI summary

Disclosed is a sustained release lipid pre-concentrate, comprising: a) a sorbitan unsaturated fatty acid ester having a polar head with at least two or more -OH (hydroxyl) groups; b) a phospholipid; and c) a liquid crystal hardener, free of an ionizable group, having a hydrophobic moiety of 15 to 40 carbon atoms with a triacyl group or a carbon ring structure. The lipid pre-concentrate exists as a liquid phase in the absence of aqueous fluid and forms into a liquid crystal in the presence of aqueous fluid. Also, a pharmaceutical composition further comprising a pharmacologically active ingredient plus the pre-concentrate is provided.