Abstract

Combination therapy has gained a lot of importance nowadays due to greater patient acceptability, increased potency, action at different sites, fewer side effects and quicker relief.  Literature survey revealed that various methods like UV, HPLC, and HPTLC have been reported for the analysis of Olmesartan and Indapamide individually and combined with other drugs but there was no HPTLC method for their simultaneous estimation. As HPTLC methods offer advantages in being simple, faster and cost effective, an accurate, precise, and specific HPTLC method has been developed for the simultaneous estimation of Olmesartan and Indapamide. Chromatographic separation was performed on HPTLC Aluminium plates coated with Silica gel 60 F₂₅₄ adsorbent. The mobile phase optimised for the separation was Toluene: Chloroform: Ethanol (4:4:1 v/v). The separated components gave R_f values of 0.15 and 0.47 for Olmesartan medoxomil and Indapamide, respectively. The linear regression analysis data for the calibration plots showed good linear relationship with r value 0.99930 and 0.99660 for Olmesartan medoxomil and Indapamide respectively, in the concentration range of 100 to 700 ng/spot for Olmesartan and 100 to 600 ng/spot for Indapamide. The method was validated according to the ICH guidelines with respect to accuracy, precision, specificity and robustness. The LOD and LOQ were 100 and 300 ng/spot respectively for Olmesartan and 100 and 300 ng/spot respectively for Indapamide. The proposed, developed and validated HPTLC method can be used as an important tool for identification and quantitative determination of Olmesartan medoxomil and Indapamide in bulk drugs and pharmaceutical formulations.