In vivo evaluation of newly developed losartan potassium sustained release dosage form using healthy male Indian volunteers

Sustained release (SR) matrix tablets of losartan potassium were prepared by wet granulation using xanthene as the polymer. The studies indicated that the drug release can be modulated by varying the concentration of the polymer and the fillers. The estimation of losartan potassium from human plasma method involves simple protein precipitation techniques using nifedipine as internal standard. Chromatographic separation was carried out on a reversed phase C18 column using mixture of 0.5% triethyl amine (pH 3.5) and acetonitrile (60:40, v/v) at a flow rate of 1.0 mL/min with UV detection at 225 nm. The method was validated and found to be linear in the range of 20-300 ng/ml. An open, randomized, two-treatment, two period, single dose crossover, bioavailability study in 24 fasting, healthy, male, volunteers was conducted. Various pharmacokinetic parameters including AUC0–t, AUC0–∞, Cmax, Tmax, T1/2, and elimination rate constant (Kel) were determined from plasma concentration of both formulations. These results indicated that the analytical method was linear, precise and accurate. The sustained and efficient drug delivery system developed in the present study will maintain plasma losartan potassium levels better, which will overcome the drawbacks associated with the conventional therapy