Christensen F N, Hansen F Y, Bechgaard H
J Pharm Sci. 1982 Jun;71(6):694-9. doi: 10.1002/jps.2600710622.
The in vitro release of drugs from controlled-release dosage forms has been studied in terms of a diffusion model. The model has been applied to a pellet formulation containing propoxyphene hydrochloride. It is demonstrated that the model may be used to predict the drug release profile adequately, when the pellet size is changed and when the thickness of the coating is varied. The size distribution of pellets in an experiment may be too broad to justify a simulation with just one average pellet size. Therefore, the results for pellets of the same size are generalized to any size distribution of pellets in an experiment. This is only trivial if sink condition exists in the extraction medium, since under that condition, the release from each pellet type is independent of the releases from other pellet types. In that case, the total release may therefore be found as the sum of the individual releases. In the general case considered here, the releases are coupled.
已根据扩散模型研究了控释剂型中药物的体外释放。该模型已应用于含盐酸丙氧芬的微丸制剂。结果表明，当微丸大小改变以及包衣厚度变化时，该模型可用于充分预测药物释放曲线。实验中微丸的尺寸分布可能过宽，以至于仅用一个平均微丸大小进行模拟并不合理。因此，将相同大小微丸的结果推广到实验中任何微丸尺寸分布情况。如果萃取介质中存在漏槽条件，这只是个小问题，因为在该条件下，每种微丸类型的释放与其他微丸类型的释放无关。在这种情况下，总释放量可通过各个释放量之和得出。在此处考虑的一般情况下，释放是相互关联的。
