Zou Hao, Jiang Xuetao, Kong Lingshan, Gao Shen
Department of Pharmaceutics, School of Pharmacy, Second Military Medical University, Shanghai, P.R. China.
Chem Pharm Bull (Tokyo). 2007 Apr;55(4):580-5. doi: 10.1248/cpb.55.580.
A blend of floating and pulsatile principles of drug delivery system seems to present the advantage that a drug can be released in the upper GI tract after a definite time period of no drug release. The objective of this study was to develop and evaluate a floating and pulsatile drug delivery system based on an impermeable cylinder. Pulsatile capsule was prepared by sealing the drug tablet and the buoyant material filler inside the impermeable capsule body with erodible plug. The drug delivery system showed typical floating and pulsatile release profile with a lag time followed by a rapid release phase. The lag time prior to the pulsatile drug release correlated well with the erosion properties of plugs and the composition of the plug could be controlled by the weight of the plug. The buoyancy of the whole system depended on the bulk density of the dosage form. Gamma-scintigraphic evaluation in humans was used to establish methodology capable of showing the subsequent in vivo performance of the floating and pulsatile release capsule. Developed formulations showed instantaneous floating with no drug release during the lag time followed by a pulse drug release. From the gamma-scintigraphic results, the pulsatile release capsule we prepared could achieve a rapid release after lag time in vivo, which was longer than that in vitro. The scintigraphic evaluation could confirm qualitatively that the system with in vitro lag time of 4.0 h provided, with relatively high reproducibility, a pulsatile release occurred around 5.0 h after administration.
在一段无药物释放的特定时间段后，药物能够在上消化道释放。本研究的目的是研发并评估一种基于不透性圆柱体的漂浮和脉冲药物递送系统。通过用可蚀塞将药片和浮力材料填充物密封在不透性胶囊体内来制备脉冲胶囊。该药物递送系统呈现出典型的漂浮和脉冲释放曲线，先是有一段滞后时间，随后是快速释放阶段。脉冲药物释放前的滞后时间与塞子的侵蚀特性密切相关，并且塞子的组成可以通过塞子的重量来控制。整个系统的浮力取决于剂型的堆积密度。在人体中进行的γ闪烁扫描评估用于建立能够展示漂浮和脉冲释放胶囊后续体内性能的方法。所研发的制剂显示出瞬间漂浮，在滞后时间内无药物释放，随后是脉冲药物释放。从γ闪烁扫描结果来看，我们制备的脉冲释放胶囊在体内滞后时间后能够实现快速释放，且体内滞后时间比体外的更长。闪烁扫描评估能够定性地确认，体外滞后时间为4.0小时的系统在给药后约5.0小时以相对较高的重现性发生了脉冲释放。
