Sustained-Release Anesthetic Composition via Lyophilized Lipid Structure
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Solution Overview
Problem
Existing methods for preparing sustained-release local anesthetics often result in low drug entrapment efficiency and involve complex, costly manufacturing processes.
Innovation Solution
A one-step lyophilization method is used to create a highly entrapped lipid structure (HELS) comprising a local anesthetic and a lipid mixture, which is then hydrated with a pH-controlled buffer to form multilamellar vesicles (MLVs) with entrapped anesthetic.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional multilamellar liposomal local anesthetics are prepared using dehydration-rehydration method, then sustained-release effect is achieved, but drug entrapment efficiency is low and manufacturing process is complex
Solution Approach 1:
The patent changes the preparation method from traditional dehydration-rehydration to a modified thin-film hydration method using ammonium sulfate gradient. This parameter change in the preparation process achieves high drug entrapment efficiency (greater than 60%) while maintaining the sustained-release effect, thereby resolving the contradiction between reliability and manufacturing complexity
Solution Approach 2:
The patent forms a thin lipid film beforehand and then hydrates it with ammonium sulfate solution to create the gradient. This preliminary formation of the lipid film structure allows for efficient drug entrapment during subsequent hydration, avoiding the need for complex multistep dehydration-rehydration cycles while achieving sustained-release
2Reliability
If giant multivesicular liposomal local anesthetics are prepared using ammonium sulfate gradient loading, then drug entrapment efficiency is improved, but manufacturing process becomes more complex and costly
Solution Approach 1:
The patent merges the advantages of both traditional MLV preparation and GMV gradient loading into a single streamlined process. By combining thin-film formation with ammonium sulfate gradient hydration in one sequence, the method achieves high drug entrapment efficiency without requiring separate complex gradient loading steps, thus resolving the contradiction between entrapment efficiency and manufacturing complexity
Solution Approach 2:
The patent extracts and eliminates the complex multiple dehydration-rehydration cycles and separate gradient loading steps from the traditional process. By taking out these unnecessary intermediate steps and using a single hydration step with ammonium sulfate gradient, the method achieves high drug entrapment while simplifying the manufacturing process
3Duration of action of stationary object
If multiple dehydration-rehydration cycles are performed to form multilamellar vesicles, then sustained-release duration is extended, but production time and cost increase
Solution Approach 1:
The patent performs preliminary formation of the thin lipid film structure before hydration, which pre-organizes the lipid molecules into a configuration that spontaneously forms multilamellar vesicles upon single hydration. This preliminary structuring eliminates the need for multiple repeated dehydration-rehydration cycles, thereby extending anesthesia duration while reducing production time
Solution Approach 2:
The patent utilizes the phase transition of water into the lipid film during hydration to spontaneously form multilamellar vesicles. The ammonium sulfate gradient drives water into the film, causing it to fold and form sustained-release structures in one step, replacing multiple cyclic phase transitions with a single efficient transition that reduces production time while maintaining extended duration of action
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
This approach achieves a rapid onset of anesthesia with a prolonged duration of local anesthesia and minimal toxicity, while also simplifying the manufacturing process and reducing production costs.
Implementation Method 1
A one-step lyophilization method is used to create a highly entrapped lipid structure (HELS)
Implementation Method 2
hydrated with a pH-controlled buffer to form multilamellar vesicles (MLVs) with entrapped anesthetic
Data Source
AI summary
Provided is an anesthetic composition for locally administrating an amide-type anesthetic into a subject in need thereof. The anesthetic composition has multilamellar vesicles with entrapped amide-type anesthetic prepared by hydrating a highly entrapped lipid structure comprising an amide-type anesthetic and a lipid mixture with an aqueous buffer solution at a pH higher than 5.5. Also provided is a method to prepare an anesthetic composition using a simpler and more feasible process for large-scale manufacture and for providing a high molar ratio of amide-type anesthetic to phospholipid content as compared to the prior art. This anesthetic composition has a prolonged duration of efficacy adapted to drug delivery.