Vol. 7, Issue 8 (2018)

Author(s):
Alka N Choudhary, Ajay Chaudhary and Kamlesh K Dutta

Abstract:
Objective: The present study was designed to develop a RP-HPLC method which is capable of estimating the content and release of Levodopa, Carbidopa and Entacapone simultaneously in combined dosage form. Methods: Selection of diluents for a clean sample was based on the solubility to provide sink condition for the target analytes in common. C18 column was selected as the stationary phase. Gradient Scouting Technique was opted to screen whether isocratic or gradient method is the possibility with different mobile phases. Detection wavelength was selected with help of PDA detector screening over the wavelength 200 – 400 nm. Strength & pH of buffer, column temperature, flow rate and injection volume were optimized by performing trials at different buffer strengths & pHs, column temperatures, flow rates and injection volumes respectively. Results: Simultaneous separation of Levodopa, Carbidopa and Entacapone was achieved on a Sunshell, Fused Core C18 column (150 mm x 4.6 mm x 2.6 µm) as stationary phase with combination of mobile phases; Phosphate Buffer, pH 3.0 and Methanol in gradient mode at flow rate of 1.0 ml/min, column temperature kept at 35ºC, PDA/UV detector at 280 nm and injection volume 5 µL. The diluents used for sample preparation was Phosphate Buffer, pH 5.5. The retention time of Levodopa, Carbidopa and Entacapone were found to be 2.27, 3.43 and 11.77 minutes respectively with tailing factor ≤ 1.5, resolution > 2 and NTP > 2000 for each analyte peak. Conclusion: Simple, economical and rapid method was developed and further validated successfully as per ICH: Q2 (R1).