Content uniformity and dissolution tests of triplicate mixtures by a double divisor-ratio spectra derivative method.

The use of a UV double divisor-ratio spectra derivative calibration for the simultaneous analysis of synthetic samples and commercial tablet preparations without prior separation is proposed. The method was successfully applied to quantify three ternary mixtures, chlorpheniramine maleate and caffeine combined with paracetamol or acetylsalicylic acid and a mixture of acetylsalicylic acid combined with paracetamol and caffeine, using the information in the absorption spectra of appropriate solutions. Beer's law was obeyed in the concentration range of 0.84-4.21 microg/ml for chlorpheniramine maleate, 1.60-15.96 microg/ml for caffeine, 2.0-20.0 microg/ml for acetylsalicylic acid and 1.58-15.93 microg/ml for paracetamol. The whole procedure was applied to synthetic mixtures of pure drugs as well as to commercial preparations (Algon) by using content uniformity and dissolution tests (USP 24) and was found to be precise and reproducible. According to the dissolution profile test more than 84% of paracetamol and caffeine were dissolved within 20 min. Acetylsalicylic acid dissolved more slowly, taking about 45-60 min to dissolve completely. A chemometric method partial least squares (PLS) and a HPLC method were also employed to evaluate the same mixtures. The results of the proposed method were in excellent agreement with those obtained from PLS and HPLC methods and can be satisfactorily used for routine analysis of multicomponent dosage forms.