New Method for Spectrophotometric Estimation of New Anti Epileptic Drugs in Solid Dosage Form

The present paper describes a simple, sensitive, accurate and reproducible method for spectrophotometric estimation of some new antiepileptic drugs like Oxcarbazepine and Lamotrigine in bulk and solid dosage forms. Oxcarbazepine and Lamotrigine are antiepileptic and mood stabilizing drugs used primarily in the treatment of epilepsy and bipolar disorder. Oxcarbazepine is a structural derivative of Carbamazepine, adding extra oxygen to the dibenzepine ring whereas Lamotrigine is a diamine with dichlorodiphenyl groups. A visible double beam spectrophotometer with a matched pair of 1 centimeter quartz cell was used for experimental purposes and analytical reagent grade acetonitrile in distilled water was used as a solvent. Oxcarbazepine showed maximum absorbance at a wavelength of 257 nm and obeyed Beer’s law in the concentration range of 2-50 mcg/ml. Previously reported spectrophotometric method as observed in literature survey gives a method based on the formation of a coloured complex. The present communication, a simple spectrophotometric method is developed for the estimation of Oxcarbazepine in its solid dosage form using distilled water as a solvent.
Lamotrigine showed maximum absorbance at a wavelength of 304 nm and obeyed Beer’s law in the concentration range of 10-50 mcg/ml. Previously reported spectrophotometric method as observed in literature survey gives a method which uses methanol as a solvent which might not be suitable for oral dosage form. The present communication using distilled water as a solvent is therefore more convenient, accurate and reproducible.
The results of the analysis were validated statistically and by recovery studies.