RESUMO
Controlled release dosage forms provide sustained therapeutics effects for prolonged period of time and improve patient compliance. In present study, controlled release co-precipitates of Metoprolol Tartrate and Losartan Potassium were prepared by solvent evaporation method using polymers such as Eudragit RL 100 and Carbopol 974PNF and controlled release tablets were directly compressed into tablets. In-vitro dissolution of controlled release coprecipitates were performed by USP Method-II [paddle method] and tablets were evaluated by USP Method-I [rotating basket method] in phosphate buffer [PH 6.8] using pharma test dissolution apparatus. The temperature was maintained constant at 37 +/- 1.0 0 C and the rotation speed of paddle and basket was kept constant at 100rpm. Drug release mechanisms were determined by applying Power Law kinetic model. The difference and similarity of dissolution profiles test formulations with reference standards were also determined by applying difference factor [f1] and similarity factor [f2]. The results showed that the controlled release co-precipitates with polymer Eudragit RL 100 of both the drug extended the drug release rates for 10 hours and those having polymer Carbopol 974P NF extended the drug release rates for 12 hours. The controlled release tablets prepared from controlled release co-precipitates extended the drugs release up to 24 hours with both the polymers. The drug was released by all tests anomalous non fickian mechanism except F1 and F5 do not follow Power Law. The f1 and f2 values obtained were not in acceptable limits except F15 whose values were in acceptable limits. It is concluded from the present study that polymers [Eudragit RL 100 and Carbopol 974P NF] can be efficiently used in development of controlled release dosage forms having predictable kinetics
RESUMO
The aim of the study presented is to formulate and evaluate Acarbose controlled release matrix tablets by means of different grades of polymer Ethocel and different co-excipients with the intention to see their effects on drug release profile during in vitro dissolution studies. Controlled release dosage forms is gaining rapid popularity due to its positive aspect of reduction in dosage frequency and curtailing side effects. Controlled released tablets of Acarbose were prepared by direct compression method, using Ethocel[registered sign] Standard 7 Premium and Ethocel[registered sign] Standard 7 FP premium polymer. The effect of co-excipients including hydroxypropyl methylcellulose [HPMC], Carboxymethyl cellulose [CMC] and starch on the drug placing 30% lactose were also examined. In-vitro studies were carried out with the help of phosphate buffer [PH 7.4] as dissolution medium. Drug release mechanism was assessed by applying various kinetic models. Similarly / dissimilarity factor f[2]/ f[1] were applied for determination of dissolution profile of the test and reference formulations. Physiochemical characteristics were in the USP satisfactory limits. Conventional Acarbose tablet released 97% of the drug within 2 hrs. Ethocel[registered sign] Standard 7 premium and Ethocel[registered sign] standard 7 FP released 59.9% and 47.01% of the drug within 6 and 99.9% and 97% within 24 hours, respectively. This effect possibly has been aceived owing to the smaller particle size of the Ethocel[registered sign] Standard 7 FP premium which show evidence of anomalous, nonfickian release kinetics. Co-excipients like HPMC, CMC and starch augment the drug release rates from the matrices which may be attributed to their hydrophilic nature. Ethocel[registered sign] Standard 7 Premium and Ethocel[registered sign] Standard premium 7 FP polymers show a promising response in fruitful production of controlled release tablets by direct compression method