Maryam Jahani - Department of Pharmaceutical Control, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran
Maryam Akaberi - Department of Pharmacognosy, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran
Tahereh Heidari - Department of Chemistry, Faculty of Sciences, Ferdowsi University of Mashhad, Mashhad, Iran
Hossein Kamali - Department of Pharmaceutics, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran
Mozhgan Nejabat - Department of Medicinal Chemistry, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran
Omid Rajabi - Department of Pharmaceutical Control, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran
Farzin Hadizadeh - Biotechnology Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran

Objective(s): A new binary mixture containing mometasone furoate (MF) and calcipotriol (CP) is suggested to manage psoriasis; since the combined stability profile of these drugs is poorly understood.Materials and Methods: Herein MF, CP, and their mixtures were subjected to various stress conditions. Also, stability-indicating HPLC was developed and validated according to ICH guidelines with Box-Behnken design. The degradation products (DPs) were predicted in silico and identified using LC-MS. The bioactivity and toxicity of DPs were studied using molecular docking and alamarBlue assay, respectively. Spectroscopic techniques of the first derivative, first-derivative ratio, and the mean-centering of ratio spectra were also used to determine MF and CP in the mixture because of spectra overlapping. Results: The major degradants for MF in alkaline conditions were DP۱, DP۲, and DP۳, while in thermal and UV conditions, only DP۱ was generated. CP gave one degradant in all conditions. No new impurity was observed in the MF and CP mixtures. The results of spectrophotometry showed good linearity in the range of ۴-۵۰ and ۲-۲۰ µg/ml, while linearity for HPLC was in the range of ۴–۵۰ and ۰.۵–۲.۵ µg/ml for MF and CP, respectively. Recovery was ۹۹.۶۱–۱۰۰.۳۸% for UV and ۱۰۰.۴% for HPLC methods of MF and ۱۰۰.۶–۱۰۱.۴% for UV and ۹۹.۵% for HPLC methods of CP.Conclusion: The developed methods can be used as simple, accurate, precise, and rapid techniques for routine quality control of MF and CP mixtures.

Calcipotriol, HPLC, Mometasone furoate, Spectrophotometric, Stress study, Validation