Synchronized Quantitative Assessment of Corticosteroid and Bronchodilator in Rotacaps by HPTLC using Fractional Factorial Design

Background: A validated high performance planar chromatographic analysis for a combination medication of corticosteroids mometasone furoate and bronchodilators formoterol fumarate available as Evocort®: inhaler in market was developed. It is used for treating asthma, a reversible obstructive airways disease. Materials and Methods: The HPTLC chromatographic condition was optimised using aluminium sheets formerly coated with silica gel 60F₂₅₄ as stationary phase and toluene: methyl alcohol: methanoic acid (12.5:4:0.3 v/v/v) as mobile phase. Results: Formoterol fumarate and mometasone furoate concentration was found to be directly proportional to peak area in the range of 120-720 ng/band and 3996-23976 ng/band, respectively. Results of precision studies were between 0.77-1.274 stated in %RSD and recovery studies ranged from 99-101% indicating very low inter day variability and good reproducibility of the method. Fractional factor design was applied to five factors i.e. volume of mobile phase, amount of methyl alcohol in mobile phase, chamber saturation time, development distance, time from chromatography to scanning to study its effect on retardation factor and peak area of both the drug. Conclusion: The 3D response surface graphs exposed that ratio of methyl alcohol in the mobile phase was slightly rigorous factors affecting the responses. The compatibility of linearity ranges with ratio in their combined rotacaps and also nonappearance of excipients interference recommends application of the proposed methods in quality control analysis of cited drugs in commercial rotacaps.