Study of factors influencing mixing of powders and homogeneity of the blend.

Charles University, Faculty of Pharmacy in Hradci Králové Department of: Department of Pharmaceutical Technology Consultant: Doc. PharmDr. Zdeňka Šklubalová, Ph. D. Student: Klára Morávková Title of Thesis: Study of factors influencing mixing of powders and homogeneity of the blend. In pharmacy, the proper mixing process is an important aspect in achieving of the final dosage form homogeneity. The influence of the rotational speed of the mixing cube and the amount of the blended mixture on the homogeneity of the blend of a model active substance, acetylsalicylic acid, and an excipient, microcrystalline cellulose, was studied in this thesis. The drug content in the samples taken at time intervals was estimated using in the near infrared spectroscopy. The homogeneity was assessed by variations in the area under spectra for the powder mixture or after compression into the tablets. For the studied mixtures, the best homogeneity results were achieved when mixing 400 g of mixture at a speed of 34 rpm and the mixing time 80 s