Stability Evaluation of Minoxidil in FOAMIL Foam Base with Bracketing Study Design
Rodrigo Lupatini1, Raman Sidhu2, Harshad Patel1
1MEDISCA, Montreal, Quebec, Canada.
International Journal of Pharmaceutical Compounding
|June 14, 2021
Summary
This study confirms that minoxidil foam formulations in FOAMIL are stable for 180 days, offering a gentler topical hair loss treatment. The new vehicle minimizes side effects associated with traditional minoxidil solutions.
Area of Science:
- Pharmaceutical Sciences
- Dermatology
- Drug Delivery Systems
Background:
- Topical minoxidil is a widely used hair loss treatment.
- Conventional minoxidil solutions often contain irritating inactive ingredients like propylene glycol and alcohol.
- These ingredients can cause undesirable side effects, prompting the need for alternative formulations.
Purpose of the Study:
- To evaluate the 180-day stability of compounded minoxidil solutions using FOAMIL, a novel propylene glycol-free and alcohol-reduced foam vehicle.
- To assess the physicochemical and antimicrobial stability of minoxidil solutions at various concentrations (2%, 5.5%, 6%, 15%) in the FOAMIL vehicle.
- To determine the suitability of FOAMIL as a vehicle for stable topical minoxidil formulations.
Main Methods:
- A 180-day stability-indicating study was conducted on four compounded minoxidil solutions (2%, 5.5%, 6%, 15%) in FOAMIL.
- Samples were prepared by mixing minoxidil with FOAMIL and packaged in foamer bottles.
- Physicochemical analyses (strength, pH, physical stability) and antimicrobial effectiveness testing were performed at predetermined time points up to 180 days.
Main Results:
- All tested minoxidil concentrations in FOAMIL remained within the United States Pharmacopeia (USP) specification (90%-110%) for 180 days.
- No significant changes were observed in pH measurements or physical stability (color, odor, precipitation).
- The preservative system met USP requirements for antimicrobial effectiveness throughout the 180-day study period.
Conclusions:
- Minoxidil solutions compounded in FOAMIL demonstrate excellent stability for at least 180 days under ambient conditions.
- FOAMIL is a suitable vehicle for compounding minoxidil solutions, offering a potentially less irritating alternative for topical hair loss treatment.
- The study supports the stability of minoxidil concentrations between 2%-5.5% and 6%-15% in FOAMIL, based on FDA bracketing guidance.
