Spectrophotometric determination of α-tetracycline and β-phenylphrine in nitro drug compounds

In this study, concentration of α-tetracyclines and β-Phenylphrine were determined by reacting them with coupling reagent in the presence of oxidizing agent. A violet colour product was formed after reaction of α-tetracyclines with N.N.-diethylpara-phenylenediamine in the presence of N-bromosuccinimide an oxidizing agent in a basic medium of sodium bicarbonate. Similarly, β-Phenylphrine was reacted with N-dimethylparaphenylamine dihydrochloride a coupling agent and ferric potassium cyanide an oxidizing agent. The pH of the solution was maintaind at 8.4 with sodium hydroxide solution. The UV -VIS analysis of final reagent showed that, α-tetracyclines and β-Phenylphrine give maximum absorbance at 552 nm and 675 nm respectively. Moreover, the limit of detection of α-tetracyclines was observed LOD=0.329 µg.ml-1 with R2 =0.9942, and for β-Phenylphrine 0.045 µg.ml-1 with R2 =0.9991 value. The standard deviation of the methods does not exceed to 1.741%, which support that both direct method and standard method for determination of drugs in pharmaceutics are supporting to each other