Simultaneous RP-HPLC estimation and validation of metronidazole, furazolidone, and dicyclomine in capsule

For the first time, a new, simple, precise reversed-phase high-performance liquid chromatography method was developed for the simultaneous estimation of metronidazole, furazolidone, and dicyclomine hydrochloride in capsule dosage form. The method was performed with Thermo, C8 (150 mm×4.6) column. The best separation was achieved by gradient elution with mobile phase of acetonitrile, water (40:60), and 20 mm phosphate buffer with 10% w/v sodium hydroxide (pH 7.5) with a detection wavelength of 215 nm. The separation was completed within 15 min of runtime. The retention time of metronidazole, furazolidone, and dicyclomine hydrochloride was found to be 1.79, 2.45, and 11.50 min, respectively. The proposed method was found to be linear. The method was statistically validated as per the ICH guidelines and shown to be simple, accurate, precise, linear, and reproducible in the range of 40.2–60, 40.2–60.4, and 3–5 µg/mL for metronidazole, furazolidone, and dicyclomine, respectively. For the first time, the developed method foretells the suitability of the method for the simultaneous estimation of three drugs in the commercially available dosage forms.