Utility of certain pi-acceptors for the spectrophotometric determination of perindopril.

Simple, rapid, accurate and sensitive spectrophotometric methods are described for the determination of perindopril. The methods are based on the reaction of this drug as n-electron donor with 2,3-dichloro-5,6-dicyano-p-benzoquinone(DDQ)-7,7,8,8- tetracyanoquinodimethane (TCNQ), tetracyanoethylene (TCNE), chloranil (CL) and p-chloranilic acid (p-CA) as pi-acceptors to give highly coloured complex species. The coloured products are measured spectrophotometrically at 588, 843, 419, 550 and 520 nm for DDQ, TCNQ, TCNE, CL and p-CA, respectively, optimization of different experimental conditions is described. Beer's law is obeyed in the range of 20-200 micrograms ml-1 and colours were produced in non-aqueous media and were stable for at least 1 h. Application of the suggested methods to perindopril tablets are presented.