Summary.

Technological and biopharmaceutical studies were performed to determine the influence of the type of the hydrogel matrix and the polymer molecular weight and concentration on the processes of trimetazidine hydrochloride release from HPMC hydrogel matrices. It was established that both the tablets preparation techniques and the viscosity grade of the hydrophilic HPMC polymer did not influence the process of trimetazidine release in the viscosity range between 4000 cps and 100 000 cps. The incorporation of fillers with different hydrophilicity like lactose monohydrate, Starch 1500 or calcium hydrogen phosphate in a concentration range from 30 to 50% significantly changed the degree and rate of drug release. Both the classical Higuchi equitation and the Peppas kinetic model proved that the process of drug release from the model hydrogel matrices was diffusion-controlled. The values of the diffusion exponent n for the hydrogels with calcium hydrogen phosphate were lower compared to the systems containing lactose or Starch 1500 since the kinetics of the release process was influenced by the different degrees of hydration, relaxation and swelling of these hydrogel matrices. Comparing the release profiles of the model hydrogel matrices with the drug product Preductal MR the experimental conditions of the in vitro dissolution test were specified and the values of the similarity factor f2 were calculated.