Validation of derivative spectrophotometry method for determination of active ingredients from neuroleptics in pharmaceutical preparations.

First (DI) and second (D2) order derivative spectrophotometric method with an application of base line to peak technique was used for determination of active pharmaceutical ingredients (API) at two wavelengths: fluphenazine (D1 at lambda = 251 nm and lambda = 265 nm, D2 at lambda = 246 nm and lambda = 269 nm), pernazine (D1 at lambda = 246 nm and lambda = 258 nm, D2 at lambda = 254 nm and lambda = 262 nm), haloperidol (DI at = 235 nm and lambda = 253 nm, D2 at lambda = 230 nm and lambda = 246 nm), and promazine (D1 at lambda = 246 nm and lambda = 251 nm, D2 at lambda = 255 nm and lambda = 262 nm). Linear dependence of derivative values on analyte concentration is maintained in a range 3.12 microg x mL(-1) - 44.80 microg x mL(-1). Detection and determination limits are in the range 0.51 - 3.23 microg x mL(-1) and 1.27 microg x mL(-1) - 9.80 microg x mL(-1), respectively. Determination results of drug constituents are very accurate. Recovery percentage is in a range 95.50% - 103.60%.