Abstract
Two accurate, precise and sensitive high-performance thin layer chromatography (HPTLC) and high-performance liquid chromatography (HPLC) methods were developed for assay of ampicillin (AMP) and dicloxacillin (DX) in the presence of their impurity, 6-aminopenicillanic acid (APA). Method (A) is HPTLC method; using silica gel HPTLC F-254 plates as a stationary phase with methanol: chloroform: acetic acid (1:9: 0.2, by volume) as a developing system. All the bands were scanned at 220 nm. Method (B) is reversed phase- HPLC which depended on isocratic elution using C-18 column and mobile phase consisting of acetonitrile: water (60:40, v), pH adjusted to 4 with orthophosphoric acid, at a flow rate of 1 mL min(-1) and ultraviolet detection at 240 nm. The proposed methods were validated as per ICH guidelines and their linearity was evident in the ranges of 0.5-2 mu g band(-1), 0.4-2 mu g band(-1) and 0.2-1.2 mu g band(-1) for method (A) and 5-40 mu g mL(-1), 5-40 mu g mL(-1) and 2-16 mu g mL(-1) for method (B) for AMP, DX and APA, respectively. The proposed methods were successfully used for assay of AMP and DX in pure form and in pharmaceutical formulation where no interference from the excipients was detected.