4TH-DERIVATIVE SPECTROPHOTOMETRIC DETERMINATION OF SOME PHARMACEUTICAL SUBSTANCES

In this paper the fourth-derivative spectrophotometric method for the assaying of some pharmaceutical combinations was described. It was analysed the conditions for the determination of certain nan-narcotic analgoantipiretics(acetylsalicylic acid, paracetamol and salicylamide), analeptics (caffeine), vitamins (L-ascorbic acid), antioxidants (butylated hydroxyanisole), sedatives and hypnotics (phenobarbital and secobarbital) and antihistaminics (promethazine). For the determination of numbers of mentioned substances ''zero-crossing'' technique was applied, but for some of them the caracteristic peak amplitude had to be corrected. The investigated criterias were applied for the assaying of these substances in different pharmaceutical combinations. This method is simple, rapid, precize and accurate and could be applied for the quantitative analysis of pharmaceutical preparations.