Development and validation of chromatographic methods for simultaneous determination of ibuprofen and famotidine in presence of related substances in pharmaceutical formulations

Abstract

Two validated methods for the simultaneous determination of ibuprofen and famotidine in the presence of ibuprofen impurity (4-isobutylacetophenone) and/or famotidine degradation products were described. The first method was a simple TLC method where separation was performed on silica gel plates using ethyl acetate: methanol: ammonia (9:2:1, by volume) as a mobile phase. Rf values were found to be 0.40, 0.94, 0.66, 0.27, 0.83 for ibuprofen, 4-isobutylacetophenone, famotidine, famotidine acid and basic degradation products, respectively. The second method was HPLC on C18 column using methanol: phosphate buffer pH 3 (80:20, v/v) as a mobile phase. Retention times were found to be 2.2 min, 9.9 min, and 8.6 min for famotidine, ibuprofen, and 4-isobutylacetophenone, respectively. Both methods were validated according to the ICH guidelines and applied for the determination of the two drugs in pure powder and combined dosage form without interference from the excipients.