The use of the DSC method in quantification of active pharmaceutical ingredients in commercially available one component tablets

Beside many known applications of the differential scanning calorimetry method in the study of solid phase substances, there is a possibility to use it in quantitative analysis. For this purpose, a relationship between the signal value of analyte (enthalpy change ΔH) and its concentration in the matrix is used. This paper shows how the choice of a matrix (used excipients) and the method of its preparation (as a non-micronized or micronized mixture) affect the final result of such determinations. The problem has been shown by measuring different, commercially available tablets of paracetamol. The calculated results obtained from micronized, respectively, cellulose and starch, mixtures were ranging from 456.83 mg to 491.42 mg and 465.58 mg to 486.68 mg while for non-micronized, physical mixtures were distinctly different, and were ranging, respectively, from 433.27 mg to 455.12 mg and 449.04 to 473.36 mg. The DSC method was validated and as a reference, a validated TLC method with densitometric detection was used