Application of π acceptors to the spectrophotometric and spectrofluorimetric determination of vincamine and naftidrofuryl oxalate in their pharmaceutical preparations.

Three different spectrophotometric and two spectrofluorimetric methods have been developed and validated for the determination of vincamine (VN) and naftidrofuryl oxalate (NF) in tablets. The spectrophotometric methods depend on charge transfer complex formation between each of VN and NF with 7,7,8,8-tetracyano-quinodimethane (TCNQ), 2,6-dichloroquinone-4-chloroimide (DCQ) and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) at 843, 580 and 588 nm, respectively. The spectrofluorimetric methods are based on the formation of charge transfer complex between each of the two drugs and TCNQ, with measurement of the fluorophore formed at 312/375 and 284/612 nm, respectively, or with DDQ at 400/475 and 284/396 nm, respectively.