Membrane permeation-controlled transdermal delivery devices for the controlled delivery of methylephedrine HCl were developed using calcium alginate membrane as rate-controlling membrane. To increase the solubility of methylephedrine HCl in the systems, HPMC and agar binary gel was used as drug reservoir. In vitro drug release studies were carried out using modified Franz diffusion cells. The result shows that the step of drug penetrating through the calcium alginate membrane is rate-limiting, then the rate of drug release from the patch is considered to be membrane controlled. The release kinetics of ointment and patch may be square root time dependent and the highest regression coefficient was obtained with the Higuchi model. The surface permeability of ointment was reduced by crosslinking of the membranes and enable drug continuous release over prolonged periods. Above results will be helpful to possible development of rate-controlling membrane transdermal delivery systems for the other drugs. 本研究所發展之薄膜滲透控釋型經皮輸移系統，是使用藻酸鈣薄膜為鹽酸甲基麻黃素的速率控釋膜，為了增加鹽酸甲基麻黃素在系統中的溶解度，則選用HPMC與洋菜膠混合膠體為基質，Franz擴散槽進行體外藥物釋出試驗，結果顯示，藥物穿透藻酸鈣薄膜為速率決定步驟，因此該貼劑之藥物釋出速率可視為薄膜滲透控釋。軟膏與貼劑之藥物釋出動力學與時間開根號有關，Hiquchi模式解析能獲得最佳的迴歸係數，軟膏表面的滲透性可藉由薄膜的交鏈而降低，可造成藥物長時間的持續釋出。上述實驗結果有助於將來發展其他藥物之薄膜滲透控釋型經皮輸移系統。
