HLPC has been an important technique in the analysis of pharmaceutical principles in pharmaceutical preparations. Sometimes, however, the use of this technique presumed to be more rapid, simple and reliable, is not the most adequate. In various cases simpler and more rapid methods can be used with clear advantages. In the present work the comparison of the quantitative results obtained with the HPLC recommended method with those resulted from the UV-Visible diffuse reflectance determination procedure and with the classical transmittance measurements of aqueous solutions was done. The experimental results of the three methods were compared through the statistical Student’s t test and agreement was observed at 95% confidence level. Among them the diffuse UV-Visible reflectance procedure is the simplest and the transmittance method offered the highest precision. The accuracy of the three methods is similar. A very interesting characteristic of the proposed reflectance method is that, despite the fact that it is quantitative, no weighing of aliquots is needed.
