Cyclodextrin Eye Drop Composition for Stable A-5021 Solubilization
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Solution Overview
Problem
Existing antiviral compounds like A-5021 are poorly soluble in physiologically compatible solutions, leading to unstable formulations and ineffective treatment of herpes virus infections, particularly in ocular infections of animals.
Innovation Solution
A-5021 is solubilized under isotonic and pH neutral conditions using hydroxypropyl beta-cyclodextrin, with optional thiomersal as a preservative, to create stable eye-drop formulations with concentrations between 0.1-1% w/v, suitable for diagnosing and treating ocular herpetic infections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If A-5021 is solubilized to pharmacologically active concentrations, then antiviral efficacy is improved, but formulation stability deteriorates due to precipitation
Solution Approach 1:
The patent introduces cyclodextrin as an intermediary substance that forms inclusion complexes with A-5021. This mediator enables the drug to be solubilized at pharmacologically active concentrations (above 1 mg/mL) while maintaining formulation stability at neutral pH, resolving the contradiction between efficacy and stability.
Solution Approach 2:
The patent changes the solubility parameters of A-5021 by utilizing cyclodextrin inclusion complex formation. This allows the drug to achieve high solubility at physiological pH (7.0-7.4) without precipitation, transforming the formulation from unstable to stable while maintaining antiviral activity.
2Quantity of substance
If A-5021 is formulated at concentrations above 1 mg/mL, then treatment effectiveness is improved, but solution stability deteriorates
Solution Approach 1:
Cyclodextrin serves as a mediating agent that enables high drug concentrations (above 1 mg/mL) to be maintained in stable solution. The inclusion complex formation prevents precipitation while allowing pharmacologically active concentrations to be achieved.
Solution Approach 2:
The patent creates a composite formulation system combining A-5021 with cyclodextrin. This composite approach allows the drug to be formulated at elevated concentrations while maintaining solution stability, as the cyclodextrin-A-5021 inclusion complex prevents crystallization and precipitation.
3Quantity of substance
If pH is adjusted to below 4 or above 10 to improve solubility, then A-5021 solubility is improved, but physiological compatibility deteriorates
Solution Approach 1:
Cyclodextrin acts as a pH-independent solubilizing intermediary that enables A-5021 to achieve high solubility at neutral pH (7.0-7.4). This eliminates the need for extreme pH adjustment while maintaining both solubility and physiological compatibility for ocular application.
Solution Approach 2:
The patent changes the solubility mechanism from pH-dependent to cyclodextrin-dependent. This allows the formulation to maintain neutral pH (physiologically compatible) while achieving high drug solubility through inclusion complex formation with cyclodextrin.
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 compositions maintain stability for several hours to weeks without precipitation, effectively treating and diagnosing ocular herpes infections in animals, including felines, with minimal adverse effects.
Implementation Method 1
A-5021 is solubilized under isotonic and pH neutral conditions using hydroxypropyl beta-cyclodextrin
Data Source
AI summary
The present invention relates to an eye-drop composition comprising 2-amino-9-[[(1S,2R)-1,2-bis(hydroxymethyl)cyclopropyl]methyl]-1,9-dihydro-6H-Purin-6-one, and the use thereof for the diagnosis and treatment of herpetic eye infections in companion animals.