مطالعه پليمرها در ايجاد فرمولاسيون هان با آزادسازي كنترل شده كاپيتوپريل

Evaluation of polymers produced controlled release formulations of captopril

Captopril is an angiotension-converting enzyme inhibitor used in the treatment of hypertension. It is freellly water soluble and has an elimination half-life after oral dose of 1.7 h. Various methods are available to formulate water soluble drugs into sustained release dosage forms by retarding the dissolution rate. One of the methods used to control drug release and hence, prologn therapeutic activity is to use hydrophilic and lipophilic polymers. In this study the effects of various polymers (hydroxyprpylemethylcellulose,) ethylcellulose and sodium carboxymethylcellulose) and surfactants (sodium lauryl sulphate, ceytltriammonium bromide and arlacel 60) on the release rate of captopril were investigated. The results showed that an increase in the amount of HPMC K15M resulted in a reduction in the release rate of captopril from matrices. When the HPMC was partly replaced by NaCMC (the ratio of HPMC: NaCMC was 5:1) the release rate of the drug significantly decreased. However, there was no significant difference in release rate of captopril from matrices produced with the ratios of 5:1 and 2:1 of HPMCiNaCMC. The presence of lactose in matrices containing HPMC and NaCMC increased the release rate of captopril. It was intresting that although partial replacement of HPMC by EC reduced the release rate of the drug (ratio of HPMC: EC was 2:1), when the ratio of HPMC:EC was reduced to 1:1 the release rate was increased. The effects of various surfactants on the release rate of captopril from HPMC:EC (1:1) matrices was also investigated. The results showed that the surfactants did not significantly change the release rate of the drug. Release rate of the drug. Release data were examined kinetically and the ideal kinetic models were estimated for the drug release.