Spectrophotomeric Determination of Vigabatrin and Gabapentin in Bulk, Dosage Forms and Urine After Derivatization with P-Dimethyl Amiocinam Aldehyde

ABSTRACT

A selective and sensitive analytical method was developed for the determination of the Anticonvulsants, [Vigabatrin [I] and gabapentin [H]] in bulk, dosage forms and urine. The method is based on the reaction of both substances I, II through their aliphatic amino groups with p-dimethyl amino cinamaldehyde in non-aqueous medium to give orange color derivatives. The orange color was measured spectrophotometrically at 473 and 470 nm as lamda cmax for I and 11, respectively. The absorbance concentration plots were rectilinear over the range 20-140 micro g/mL The method applied to determine of I and II in their tablets, the percentage recoveries +/- SD [n = 10] were 100.7 +/- 0.32 and 101.2 +/- 0.41, respectively. The proposed method was successfully applied to the determination of I and II in spiked urine. The percent Recoveries +/- SD [n = 10] were 98.78 +/- 0.39 and 98.92 +/- 0.46 from spiked urine samples. The optimum conditions for the reaction were carefully investigated and incorporated into the procedure. No interference was encountered from the co administrated drugs Valporic acid, dipheny phenobarbital, carbamazepine, clonazepam, clopazam or cimetidine. A proposal of the reaction pathway was suggested the advantages of the proposed method over existing method was discussed