Goracinova K, Kllsarova Lj, Simov A
Faculty of Pharmacy, 91 000 Skopje, Vodnjanska 17, Republic of Macedonia P.O.B. 162, 91 000, Skopje, Republic of Macedonia.
Faculty of Science, Institute of Chemistry, P.O.B. 162, 91 000, Skopje, Republic of Macedonia.
Drug Dev Ind Pharm. 1995;21(3):383-391. doi: 10.3109/03639049509048119.
Verapamil hydrochloride coprecipitates were prepared using solvent-evaporation technique. Ethylcellulose, hydroxypropyl cellulose, hydroxypropyl methylcellulose phtalate HP 55 were used as polymers. The solid dispersions obtained were grounded and sieved to prepare solid dispersion granules. The dissolution behavior of solid dispersion granules was studied using buffer solutions with pH 1.5; 6.8 and half-change method during 24 hours. The drug release rate was found to be dependent on the ratio of the polymers in coprecipitates. In order to understand the drug release mechanism better, the release data were tested assuming common kinetic models. The best fit kinetic model was diffusion model and the dissolution rate constants calculated using Higuchi equation, demonstrated that dissolution rate increased with increasing the ratio of HPMCP HP 55 in coprecipitates. Physical characterization was made using X-ray diffractometry, IR spectrophotometry and DTA studies. Prepared coprecipitates were X-ray amorphous. Also, after nine months real time studies they remain amorphous, with no changes in their IR spectra and DTA curves. The dissolution rate of the test dispersions showed no significant changes during the stability studies, reflecting the stability of X-ray amorphous drug phase.
采用溶剂蒸发技术制备盐酸维拉帕米共沉淀物。使用乙基纤维素、羟丙基纤维素、邻苯二甲酸羟丙基甲基纤维素HP 55作为聚合物。将得到的固体分散体研磨并筛分以制备固体分散体颗粒。使用pH值为1.5、6.8的缓冲溶液和半变方法在24小时内研究固体分散体颗粒的溶出行为。发现药物释放速率取决于共沉淀物中聚合物的比例。为了更好地理解药物释放机制，假设常见动力学模型对释放数据进行测试。最佳拟合动力学模型为扩散模型，使用Higuchi方程计算的溶出速率常数表明，溶出速率随着共沉淀物中HPMCP HP 55比例的增加而增加。使用X射线衍射法、红外分光光度法和差示热分析进行物理表征。制备的共沉淀物为X射线非晶态。此外，经过九个月的实时研究，它们仍保持非晶态，红外光谱和差示热分析曲线没有变化。在稳定性研究期间，测试分散体的溶出速率没有显著变化，反映了X射线非晶态药物相的稳定性。
