Using Derivative Spectrophotometry for Determination of Some Drugs

Simultaneous spectrophotometric determination of olanzapine, trifluoperazine hydrochloride and carbamazepine drugs in their mixture in the ultraviolet region based on the first and second derivative spectra of absorption. The method offers an advantage of getting rid of the resulting error in the absorption values of each drug because the presence of the two other drugs can interfere in the determination of the cited drug. The results showed that no interferences from the studied excipients were found in the determination of the cited drugs. Therefore, the proposed method was applied successfully for the determination of the three cited drugs in their pharmaceutical preparations.