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Published on: September 20, 2017
Optimization of cosolvent concentration and excipient composition in a topical corticosteroid solution
S A Varia1, M M Faustino, A B Thakur
1Pharmaceutics R&D Department, Bristol-Myers Squibb Pharmaceutical Research Institute, New Brunswick, NJ 08903.
Journal of Pharmaceutical Sciences
|September 1, 1991
Summary
Developing a stable topical corticosteroid solution requires careful excipient selection. Tromethamine proved a superior buffering agent compared to potassium citrate, preventing precipitation in the cosolvent system.
Area of Science:
- Pharmaceutical Sciences
- Formulation Development
- Topical Drug Delivery
Background:
- Development of topical corticosteroid formulations requires understanding physicochemical factors.
- Novel corticosteroid tipredane (1) necessitates a stable delivery system.
- Cosolvent systems are often employed for solubilizing poorly soluble drugs.
Purpose of the Study:
- To describe physicochemical factors in developing a topical solution of tipredane (1).
- To evaluate the suitability of different buffering agents in a cosolvent system.
- To ensure drug solubility and formulation stability.
Main Methods:
- Utilized a cosolvent system (polyethylene glycol 400, propylene glycol, water) for tipredane dissolution.
- Investigated formulations with potassium citrate and tromethamine as buffering agents.
- Assessed drug solubility and excipient compatibility under storage conditions.
Main Results:
- A cosolvent system successfully dissolved 0.1% w/w tipredane and was nonirritating.
- Potassium citrate formulations showed K2SO4 precipitation due to the common ion effect with sodium metabisulfite.
- Adjusting concentrations of potassium citrate, sodium metabisulfite, and PEG 400 mitigated precipitation.
- Tromethamine-buffered formulations did not exhibit K2SO4 precipitation.
Conclusions:
- Tromethamine is a suitable buffering agent for tipredane topical cosolvent systems.
- Careful control of excipient concentrations is crucial for formulation stability.
- Understanding physicochemical interactions prevents precipitation and ensures effective drug delivery.
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