這一個研究主要比較不同的控釋系統對Tramadol的釋放機轉。Tramadol為一種水溶性好且使用在治療急性疼痛的narcotic的藥物。此篇提到的不同系統包括了以水不溶性基質和水溶性基質當間質型材料與間質型膜衣包覆系統。我們用濕式造粒法和熔合造粒法來評估藥物從水不溶性基質之間質劑型的釋放情況。由結果可以看出不管是用水不溶性系統或是水溶性系統都可以達到延長Tramadol釋放。然而藥物從這些系統釋放出來都遵循著Higuchi的模式，像是擴散(diffusional)機制。藥物的釋放速率亦可在錠劑上面進行膜衣的加工所降低，由結果看來使用膜衣來控制藥物釋放式可行的。無論如何，熔合製粒法比濕式造粒法提供較好的持續釋放藥物的機制。以上的研究都說明了，不同的製造過程和不同膜衣的比率，都可以讓Tramadol體外試驗達到持續釋放24小時。 The major purpose of this study was to compare the release kinetics of tramadol from various controlled release systems. Tramadol, a narcotics often used in treatment of chronic pain, was used as a water soluble model drug. The various systems studied including hydrophobic matrix, hydrophilic matrix and matrix-film coating systems. The drug release from hydrophobic matrix using various manufacture processes, including wet granulation method and fusion-granulation method, was also evaluated. The results indicate that prolonged tramadol release can be observed by incorporation of drug into both hydrophobic and hydrophilic matrix systems. Drug release from those systems followed a Higuchi release model, suggesting a diffusional release mechanism. The release rate of tramadol was further decreased by coating a rate controlling membrane on top of matrix and the results suggest both matrix as well as coating membrane controlled the release rate. Moreover, the fusion-granulation method provided a better sustaining effect compared to the wet granulation method. Those studies indicate that, by changing the manufacture process and adding rate controlling membrane, an in vitro prolonged release of tramadol up to 24 hours can be obtained.
