Study of Intrinsic Stability of Mometasone Furoate in Presence of Salicylic Acid by HPTLC and Characterization, Cytotoxicity Testing of Major Degradation Product of Mometasone Furoate

Abstract

Background: A successful attempt has been done to develop and validate a simple stability indicating HPTLC method for the estimation of Mometasone furoate (MF) and its degradation product in the presence of Salicylic acid (SA). The degradation product was isolated, characterized and tested for cytotoxicity. Introduction: Mometasone furoate (MF) is chemically 9,21-Dichloro-17α-[(2-furanylcarbonyl) oxy]- 11β-hydroxy-16-α-methylpregna-1,4-diene-3,20-dione, a high potency glucocorticoid. Salicylic acid (SA) has antiseptic, antifungal and keratolytic properties. Combination of MF and SA is available in the market as an ointment and is used for the treatment of skin inflammation, skin diseases, acne, skin redness and other conditions. Till now, there is no scientific documentation on HPTLC method for simultaneous estimation of MF and SA in the topical formulation; stress testing of drugs and determination of degradation products. Methods: Combination of Toluene: Ethyl Acetate: Methanol: Ammonia (6.4:1.5:2.0:0.1) was selected as the mobile phase. Detection was done by UV absorbance mode at wavelength 250 nm. Topical formulation containing MF and SA was analyzed by the developed method. The developed method was validated as per ICH guidelines. The standard drugs were subjected to stress testing like hydrolysis, oxidative, thermal and photolytic degradation. Results: Good separation with Rf values 0.61 ± 0.02 (MF) and 0.21 ± 0.02 (SA) was achieved by optimized chromatographic conditions. The % drug content was found to be 97.41±1.15 and 99.43 ± 0.73 for MF and SA, respectively in a topical formulation. From the results of validation parameters, the developed method was found to be specific, accurate, precise, sensitive and robust. After stress testing, SA was found to be stable under different stress conditions. Whereas, MF was found to be base sensitive and single degradation product was observed and isolated by preparative TLC. It was characterized by LC-MS and LC-MS/MS studies. Isolated degradation product was subjected to cytotoxicity testing on A549 and SiHa cell lines. Conclusion: A simple stability indicating HPTLC method was developed and validated for the estimation of MF and its degradation product in presence of SA. Probable structure of degradation product of MF and probable pathway of degradation was interpreted. Results of cytotoxicity testing showed that the degradation product was more cytotoxic as compared to MF against both the cell lines.