Preparation of prolonged release matrix tablets of verapamil and comparaison with coated ones

The purpose of this study was to prepare prolonged release tablets of verapamil: matrix and coated tablets, because of the importance of these systems in drug delivery and improving the patient compliance and therapeutic efficacy .Different formulations were prepared by using different release-modifiers polymers (EURL100 and EURS100). Direct compression technique was used to prepare coated tablets while matrix tablets were prepared by wet granulation and direct compression methods. The prepared formulations were evaluated in terms of their precompression parameters, physical characteristics, dissolution test and in vitro drug release kinetic studies. The results showed that matrix tablets containing 7.5or10% of EuRS100 and EuRL100 respectively and that coated tablets prepared by using coating solution (15%) which was applied about 120(in case of EuRS100) or 280 (in case of EuRL100) times were the best. These tablets released about 90-95% of verapamil within 24h

Formulation of methyldopa sustained release matrix tablets using hydrophilic polymers

The present study aims to develop sustained release (SR) matrix tablets of methyldopa using hydrophilic hydroxypropyl methylcellulose (HPMC), and to study the effect of some formulation variables (HPMC concentration and viscosity grade, combination with hydrophobic Ethylcellulose (EC) in different ratio, binder and lubricants concentrations) on the properties of prepared tablets. Matrix tablets were prepared by wet granulation method, and prepared granules and tablets were subjected to suitable physiochemical studies. Drug release kinetics showed that drug release mechanism for about all formulations was found to fit best to Higuchi model and drug release mechanism was anomalous diffusion based on release exponent value. The in-vitro dissolution studies showed that formulation F6 containing 15% of HPMC K100M and formulation F11 containing EC:HPMC K4M (5%:10%) were able to sustain the release of methyldopa up to 24 hours so these two formulations were selected as suitable formulations.

Formulation and evaluation of methyldopa sustained release matrix tablets

The objective of the present study was to formulate methyldopa sustained release matrix tablets using hydrophilic hydroxypropyl methylcellulose (HPMC) alone or in combination with hydrophobic ethyl cellulose polymer(EC). Matrix tablets were prepared by wet granulation method, and subjected to physiochemical studies. All formulations showed physiochemical properties which appear to be in compliance with pharmacopeial standards. The in-vitro dissolution studies showed that increase in concentration or viscosity of HPMC polymer led to decrease in the rate of drug release decreased. The results also revealed that Combination of HPMC K4M and EC slower drug release more than using HPMC K4M alone. Drug release kinetics of about all formulations correspond best to Korsemeyer-Peppas model and drug release mechanism was anomalous diffusion based on release exponent value.

The Influence of Type and Concentration of Polymer on Furosemide Release from Extended Hard Capsules

The aim of the present study is to prepare extended hard capsules of furosemide using Eudragit RL, Eudragit RS and Ethyl cellulose individually and in different ratios (6,8,12 and 15%). The granules were prepared by wet granulation using isopropyl alcohol as a granulating agent and then filled into capsules. The influence of different concentrations and type of polymer was studied. The prepared capsules assessed for their physicochemical properties and in-vitro drug release studies. In vitro release data show that Ethyl cellulose has more retardation than Eudragits, and Eudragit RS retards drug more than Eudragit RL does. Furthermore, higher concentration of polymer tends to more retardation than lower concentration.