STABILITY-INDICATING HPLC METHOD FOR DETERMINATION OF OFLOXACIN IN BULK DRUG AND TABLETS USING TRIFLUOROACETATE AS COUNTER ANIONS

Abstract

A stability-indicating reversed-phase HPLC method for the quantitative determination of ofloxacin in bulk samples and tablet formulation has been developed and validated. The separation was performed on a C18 column (4.6 × 250 mm, 5 µm) using an isocratic mobile phase comprising of acetonitrile and buffer pH 3.3 (16: 84, v/v) with a diode array UV/Vis detection at 294 nm. The buffer was composed of ammonium acetate (50 mM) and ion-pairing reagent, trifluoroacetic acid (20 mM). Forced degradation studies were performed on bulk sample as per ICH prescribed stress conditions using acid hydrolysis, alkaline hydrolysis, neutral hydrolysis, oxidative, thermal stress, and photolytic degradation to show the stability indicating power of the method. The proposed method provided linear responses (r²=0.9999) over the concentration range of 10–30 μg mL⁻¹. LOD and LOQ values for the active substance were 0.13 and 0.45 μg mL⁻¹, respectively. The method validation showed good results for specificity, linearity, precision, accuracy, limit of detection, limit of quantitation, and robustness. The proposed method was successfully employed for quantification of ofloxacin in tablets.

Keywords:

• counter anion
• HPLC
• ofloxacin
• stability-indicating
• trifluoroacetic acid
• validation

ACKNOWLEDGMENT

The authors gratefully acknowledge the financial support of the Faculty of Pharmacy, Silpakorn University, Thailand. We would also like to thank T.O. Laboratories, Co., Ltd., Thailand for supporting this work.

Notes

RT = room temperature.