Development of a Method for the Quantification of Clotrimazole and Itraconazole and Study of Their Stability in a New Microemulsion for the Treatment of Sporotrichosis

• Main Authors: Patricia Garcia Ferreira, Carolina Guimarães de Souza Lima, Letícia Lorena Noronha, Marcela Cristina de Moraes, Fernando de Carvalho da Silva, Alessandra Lifsitch Viçosa, Débora Omena Futuro, Vitor Francisco Ferreira
• Format: Article
• Language: English
• Published: MDPI AG 2019-06-01
• Series: Molecules
• Subjects: pre-development process; clotrimazole; itraconazole; stability; method validation; sporotrichosis
• Online Access: https://www.mdpi.com/1420-3049/24/12/2333

Sporotrichosis occurs worldwide and is caused by the fungus <i>Sporothrix brasiliensis</i>. This agent has a high zoonotic potential and is transmitted mainly by bites and scratches from infected felines. A new association between the drugs clotrimazole and itraconazole is shown to be effective against <i>S. brasiliensis</i> yeasts. This association was formulated as a microemulsion containing benzyl alcohol as oil, Tween^&#174; 60 and propylene glycol as surfactant and cosurfactant, respectively, and water. Initially, the compatibility between clotrimazole and itraconazole was studied using differential scanning calorimetry (DSC), thermogravimetric analysis (TG), Fourier transform infrared spectroscopy (FTIR), and X-ray powder diffraction (PXRD). Additionally, a simple and efficient analytical HPLC method was developed to simultaneously determine the concentration of clotrimazole and itraconazole in the novel microemulsion. The developed method proved to be efficient, robust, and reproducible for both components of the microemulsion. We also performed an accelerated stability study of this formulation, and the developed analytical method was applied to monitor the content of active ingredients. Interestingly, these investigations led to the detection of a known clotrimazole degradation product whose structure was confirmed using NMR and HRMS, as well as a possible interaction between itraconazole and benzyl alcohol.