Study On The Preparation Technique And Quality Of Losartan Potassium Capsules

Losartan (LST) is the first orally active nonpeptide angiotensin-II receptor antagonist with an improved safety and tolerability profile.Losartan, a highly effective blood pressure-lowering agent, has been widely used for the treatment of hypertension. To improve the dissolution rate and bioavailability of losartan potassium,the prescription,preparation technique,quality control,stability and bioavailability of losartan potassium capsules were studied for replace foreign and expand the use.The effects of diluents, disintegrants and bonding agents on the dissolution profile of the losartan potassium capsules were studied. To screen the formulae of losartan potassium capsules using uniform design and orthogonal design . The total score of each formula was regressed by computer. The capsules prepared according to the selected formulation had a good appearance and rapid dissolution rate, the quality conformed to the standard. The preparation process of losartan potassium capsules is simple, maturity and the quality of capsules is controllable.Study on the quality control and stability of losartan potassium capsules. A HPLC method was established for determination of losartan potassium capsules and it,s related substances. The standard curve was linear in the range of 100～500μg·ml - 1 and the correlation coefficient was 1.0000. The proposed method is simple , rapid , accurate and reliable.The dissolution parameters of T50,Td and m were obtained according to Weibull distribution. Through varied testing condition , the appearance of this capsules appeared to be very well.All the specifications examined including dissolution rate ,assay and related substances were not changed in comparison with those in preexposure.To compare the pharmacokinetic parameters and relative bioavailability of domestic and imported losartan potassium formulations in 20 healthy volunteers. A RP - HPLC method was used for the determination of serum levels of losartan potassium . The pharmacokinetics parameters after a single oral dose of 50mg domestic and imported formulations were as follows .The relative bioavailabilityof domestic table was (104.32±10.18) %.Analysis of variance revealed that there was no significant difference between the two preparations of losartan potassium formulations ( P > 0.05). The domestic and imported losartan potassium formulations were bioequivalent .The domestic losartan potassium formulations can completely take the place of the imported losartan potassium formulations.