RP-HPLC Analytical Method for the Determination and Validation of Rifapentine in Bulk and Pharmaceutical Formulations

Abstract

A simple, accurate, precise, and highly sensitive reverse-phase high-performance liquid chromatography (RP-HPLC) method was developed and validated for the estimation of Rifapentine in bulk drug and pharmaceutical dosage forms. The chromatographic separation was achieved using a C18 column (250 mm × 4.6 mm i.d., 5 μm particle size) in isocratic mode. The mobile phase consisted of a mixture of acetonitrile and 0.02 M potassium dihydrogen phosphate (KH₂PO₄) buffer (pH adjusted to 5.5 with dilute orthophosphoric acid) in the ratio 70:30 v/v, at a flow rate of 1.0 mL/min with a 10 μL injection volume. Detection was performed at 475 nm using a UV detector. The drug exhibited a well-defined peak at a retention time of 6.42 ± 0.2 minutes. The method was extensively validated as per ICH Q2(R1) guidelines covering specificity, linearity, accuracy, precision, robustness, and system suitability. Linearity was observed over the concentration range of 10-60 μg/mL with a correlation coefficient (r²) of 0.9992. Percentage recovery studies ranged from 99.20-100.65%, confiring accuracy. Intra-day and inter-day precision showed %RSD values below 2.0%. The LOD and LOQ were determined to be 0.12 μg/mL and 0.36 μg/mL, respectively. The validated method is suitable for routine quality control analysis of Rifapentine in bulk and pharmaceutical dosage forms.