Merchant Hamid A, Shoaib Harris M, Tazeen Jaweria, Yousuf Rabia
Department of Pharmaceutics, Faculty of Pharmacy, University of Karachi, Karachi-75270, Pakistan.
AAPS PharmSciTech. 2006 Sep 22;7(3):78. doi: 10.1208/pt070378.
Decreasing the dose frequency of cefpodoxime proxetil increases patient compliance; patients prefer to take the drug once daily. It also improves the rate of bacterial killing and hastens the cure from the indications, and therefore increases compliance. The hydrophilic matrix of HPMC controlled the cefpodoxime proxetil release effectively for 24 hours; hence, the formulation can be considered as a once-daily sustained-release tablet of cefpodoxime proxetil. The formulation showed acceptable pharmacotechnical properties and assay requirements. In vitro dissolution studies indicated a sustained-release pattern throughout 24 hours of the study that was comparable to the theoretical release profile. Drug release kinetics indicated that drug release was best explained by Higuchi’s equation, as these plots showed the highest linearity (=0.9734), but a close relationship was also noted with zero-order kinetics (=0.9708). Korsmeyer’s plots indicated an value of 0.57, which was indicative of an anomalous diffusion mechanism or diffusion coupled with erosion; hence, the drug release was controlled by more than one process. Hixson-Crowell plots indicated a change in surface area and diameter of the tablets with the progressive dissolution of the matrix as a function of time.
降低头孢泊肟酯的给药频率可提高患者的依从性;患者更倾向于每日服用一次该药。这也提高了细菌杀灭率并加速了适应证的治愈,从而提高了依从性。羟丙甲纤维素的亲水性基质有效地控制了头孢泊肟酯24小时的释放;因此,该制剂可被视为头孢泊肟酯的每日一次缓释片。该制剂显示出可接受的药学技术性质和含量测定要求。体外溶出度研究表明,在整个24小时的研究过程中呈现出缓释模式,与理论释放曲线相当。药物释放动力学表明,药物释放最好用Higuchi方程来解释,因为这些图显示出最高的线性度(=0.9734),但也注意到与零级动力学有密切关系(=0.9708)。Korsmeyer图表明n值为0.57,这表明存在异常扩散机制或扩散与侵蚀相结合的情况;因此,药物释放受不止一个过程的控制。Hixson-Crowell图表明,随着基质随时间逐渐溶解,片剂的表面积和直径发生变化。