Wilding I R, Hardy J G, Davis S S, Melia C D, Evans D F, Short A H, Sparrow R A, Yeh K C
Pharmaceutical Profiles Limited, Nottingham, England.
Clin Neuropharmacol. 1991 Aug;14(4):305-21. doi: 10.1097/00002826-199108000-00003.
The gastrointestinal transit and systemic absorption of Sinemet CR (50-200) controlled-release tablets and standard Sinemet (25-100) immediate-release (IR) tablets have been studied in fasted and fed healthy human subjects. Both formulations were labelled with a gamma-emitting radionuclide and their gastric emptying, colon arrival and in vivo disintegration profiles monitored using gamma scintigraphy. The IR dosage forms were found to disperse soon after administration and to empty rapidly from both fasted and fed stomachs. Erosion of the CR system was independent of food or stomach pH. The CR tablet was observed to disintegrate fully in the gastrointestinal (GI) tract, resulting in complete release of levodopa over a 3-4 h time period. Considerable intersubject variation was found to exist for levodopa absorption. Absorption was more protracted with Sinemet CR than with standard Sinemet, due to the controlled release characteristics of the tablet matrix. There was no rapid initial absorption phase and instead, a gradual build-up in the absorption profile occurred.
已在禁食和进食的健康人体受试者中研究了息宁控释片（50-200）和标准息宁速释片（25-100）的胃肠道转运及全身吸收情况。两种制剂均用发射γ射线的放射性核素标记，并使用γ闪烁显像法监测其胃排空、结肠到达及体内崩解情况。发现速释剂型给药后很快分散，并从禁食和进食的胃中迅速排空。控释系统的侵蚀与食物或胃内pH值无关。观察到控释片在胃肠道完全崩解，导致左旋多巴在3-4小时内完全释放。发现左旋多巴吸收存在相当大的个体间差异。由于片剂基质的控释特性，息宁控释片的吸收比标准息宁更为持久。没有快速的初始吸收阶段，相反，吸收曲线呈逐渐上升趋势。
