COMPARISON OF THE QUALITY AND IN VITRO DISSOLUTION PROFILES OF COMMERCIAL LOSARTAN POTASSIUM FILM TABLETS

The aim of the present study is to compare and evaluate in vitro dissolution profiles and some quality control test parameters of commercial products containing 50 mg losartan potassium that are available on drug market. Furthermore, difference (f1) and similarity (f2) factors were calculated from the dissolution data for these tablets so as to evaluate the differences and similarities of their dissolution profiles. Four brands of commercial conventional losartan potassium film tablets containing 50 mg of losartan potassium were used and coded as LP1 (original, innovative and reference product), LP2, LP3 and LP4. Some quality control tests such as diameter/thickness, crushing strength, uniformity of mass and drug assay were evaluated for losartan potassium film tablets. All commercial losartan film tablets met the criteria specified by quality control test parameters. In vitro dissolution profiles of LP2 and LP4 were similar to the in vitro dissolution profile of the reference, whereas f2 values for LP3 was found less than 50 and therefore release profile for LP3 was different than the reference profile. Dissolution data of commercial conventional losartan potassium film tablets were applied to zero order, first order, Higuchi, Hixson-Crowell and RRSBW (Weibull) kinetics. The evaluation of determination coefficient (r2) and residual mean square (RMS) indicated that the drug release from all commercial losartan potassium film tablets for distilled water and pH 6.8 phosphate buffer solution media seems to comply with RRSBW kinetic mode