RP-HPLC Method for Simultaneous Estimation of Ciprofloxacin, Tinidazole and Dicyclomine in Bulk and Tablet Dosage Form

Background: Ciprofloxacin Hydrochloride (CPX) is a fluoroquinolone antibacterial. Tinidazole (TNZ) is a nitroimidazole anti protozoal while dicyclomine hydrochloride (DIC) is an anticholinergic antispasmodic agent. The three drugs in their fixed dose combination are frequently administered in typhoid fever and infections of mixed origin. Purpose: The aim of the present research was to develop a reversed-phase high-performance liquid chromatography method for simultaneous estimation of CPX, TNZ and DIC in bulk and combined tablet formulation. Methodology: HPLC system used was Thermo Finnigan coupled to a variable wavelength UV detector and was operated in isocratic mode. The data acquisition was carried out using Chrome Quist software. The separation was achieved using HiQ Sil C₁₈ column having dimensions 250 x 4.6 mm i.d. with a particle size of 5 μm. The mobile phase consisted of buffer pH 4.0 and methanol combined in ratio of 60:40 v/v. The flow rate and UV detector was set at 1 ml/min and 218 nm respectively. Findings: The order of elution of all three drugs was found to be TNZ (5.42 min), DIC (6.96 min) and CPX (8.04 min). The linearity was established in the range of 5-30 μg/ml (CPX and TNZ) and 250-650 μg/ml (DIC). The method was validated in accordance with ICH guidelines. Conclusion: From this study it was concluded that the proposed RP-HPLC method is accurate, reproducible and precise. Application: The developed method was then successfully applied for simultaneous estimation of these drugs in marketed tablet dosage form.