FAST CHIRAL HPLC PROCEDURE FOR THE SIMULTANEOUS DETERMINATION OF DROPROPIZINE ENANTIOMERS AND ITS NONPOLAR IMPURITY IN RAW MATERIAL AND PHARMACEUTICAL FORMULATION
Objective: Levodropropizine is a novel antitussive drug, which occurs as enantiomers. They are levodropropizine (2S) [LDP] and dextrodropropizine (impurity A) (2R) [DDP]. An isocratic chiral high performance liquid chromatographic (Normal phase HPLC) method has been developed and validated for simultaneous determination of dropropizine enantiomers along with non-polar impurity-B, (1-phenyl piperazine) [1-PP] in raw material and in dosage forms.
Methods: The compounds were separated on chiral stationary phase (CSP) Chiralpak AD-H column, with a mixture of n-hexane, anhydrous ethanol, diethyl amine (DEA) in the ratio of 55:45:0.1 v/v as mobile phase at a flow rate of 1.4 ml/min. UV detection was performed at 254 nm. The method was validated for accuracy, precision, specificity, linearity, and sensitivity. The developed and validated method was successfully used for quantitative analysis of commercially available Tablets.
Results: Total chromatographic analysis time per sample was ~5 min. with 1-PP, levodrpropizne, dextropropizine eluting with retention times of 2.5 min., 3.05 min., and 3.66 min., respectively. Validation studies revealed the method is specific, rapid, reliable and reproducible for levodropropizne and its impurity A and non chiral impurity B. Calibration plots were linear over the concentration ranges 0.5-5 µg/ml and 0.5-5 µg/ml for levodropropizine and dextrodropropizine respectively.
Conclusion: The high recovery and low relative standard deviation confirm the suitability of the method for determination of dropropizine compounds in commercial tablets
