Physicochemical Stability of Microemulsions and Microemulsion-Based Gels Containing Clotrimazole

This study aimed to determine physicochemical stability of clotrimazole microemulsions (CTZ-MEs) and clotrimazole microemulsion-based gels (CTZ-MBGs). Two CTZ-MEs (ME1-C, ME2-C) and two CTZ-MBGs (MBG1-3-C, MBG2-2-C) were prepared and then kept in clear-glass containers under three different conditions, i.e., 4 degrees C, room temperature (28 +/- 2 degrees C), and 45 degrees C for three months. Afterwards, they were evaluated for physicochemical changing. The results showed that temperatures of 4 degrees C and room temperature were suitable for storage of the samples while high temperature (45 degrees C) resulted in adverse changing. After kept at 4 degrees C and room temperature for 3 months, chemical stability of all samples was in acceptable range, i.e., the drug content was higher than 90% of the initial value. However, ME2-C and MBG2-2-C exhibited more physical changing and less acceptable appearance than ME1-C and MBG1-3-C. Hence, ME1-C and MBG1-3-C were considered as stable formulations having high possibility to be further investigated for efficacy in topical drug delivery to the skin and buccal.