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In Vitro Release Testing of Acyclovir Topical Formulations Using Immersion Cells
Madhur Kulkarni1, Shrikant Potdar1, Abhijit A Date2
1Department of Pharmaceutics, Shree Chanakya Education Society's Indira College of Pharmacy, Pune, India.
Insights
Immersion cells offer a reliable method for in vitro release testing (IVRT) of topical acyclovir formulations. This optimized IVRT method effectively differentiates drug release rates and demonstrates discriminatory potential for quality control.
Area of Science:
- Pharmaceutical Sciences
- Drug Delivery Systems
- Topical Formulations
Background:
- In vitro release testing (IVRT) is crucial for topical formulations.
- Immersion cells offer a potential method for IVRT.
- Optimizing IVRT methods ensures accurate drug release assessment.
Purpose of the Study:
- To validate the use of immersion cells for IVRT of topical acyclovir formulations.
- To optimize IVRT parameters for acyclovir release.
- To assess the discriminatory capability of the immersion cell method.
Main Methods:
- Marketed acyclovir 5% cream used as a model formulation.
- Immersion cell method optimized for membrane type, temperature, media volume, agitation, and cell size.
- In-house and various marketed acyclovir topical formulations tested.
Main Results:
- Increased media temperature (32°C to 37°C) and agitation speed (50-150 rpm) enhanced acyclovir release.
- Larger immersion cell sizes (0.5, 2, 4 cm²) showed increased drug release.
- The optimized method successfully differentiated drug release among formulations with varied compositions.
Conclusions:
- The optimized immersion cell method is a simple, reliable tool for IVRT of topical acyclovir.
- This method demonstrates discriminatory potential for marketed formulations.
- Immersion cells can aid in product development and quality control for semisolid formulations.
Abstract:
The objective of the study was to reinforce the applicability of the immersion cells for the in vitro release testing (IVRT) of topical formulations by using marketed acyclovir 5% cream formulation (Cream 1) as a model. The method employing the immersion cells was optimized by studying the effect of variables, such as membrane type, media temperature and volume, agitation speed, and cell size, on acyclovir release from the formulation. The in-house formulation similar to the qualitative and quantitative composition of Cream 1 and the other trial formulations with variable compositions were prepared and studied by using the immersion cells. Various other brands of acyclovir topical formulations available in the Indian market were also subjected to IVRT by using the optimized method. An increase in the media temperature from 32°C to 37°C and the stirring speed from 50 to 100 to 150 rpm led to an increase in the drug release. As the immersion cell size increased (0.5, 2 and 4 cm™the least. The optimized IVRT method could establish the differences in the drug release rates among the formulations with the altered compositions. The method could also prove its discriminatory potential for various marketed formulations. The immersion cell method could serve as a simpler, facile, and reliable aid during product development and also as a quality control tool in assessing stability, aging, and batch-to-batch uniformity of semisolid formulations.
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