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Praziquantel (Praziquantel, PZQ) is a hydrophobic drug solubility in water of about 400ug/ml, primarily for the treatment of schistosomiasis and echinococcosis. Currently, PZQ common dosage forms are tablets, the need for frequent administration, it is necessary to develop long-term controlled release formulations PZQ implant. Five fluorouracil (5-fluorouracil ,5-Fu) belongs to antimetabolite anticancer drugs, drugs for the treatment of solid tumors has been 40 years of history, is a hydrophilic drug solubility in water up to about 17mg/ml, short half-life, systemic toxicity. Thus, the 5-Fu drugs for sustained release dosage form drug delivery implant is more appropriate. Polycaprolactone (poly (ε-caprolactone), PCL) as a biodegradable polymer, harmless to human body, for many drugs have good permeability, widely used in various pharmaceutical formulations. This experiment was prepared containing 5-Fu PZQ or two cylindrical PCL release implants, then by all means characterization study the drug loading, implant diameter, capping conditions on the release behavior of and further investigated after the release of the implant changes, including changes in the morphology of the implant, the crystallinity changes and changes in the amount of drug-containing carrier degradation of PCL changes. In this study, the hydrophobic PCL as a drug carrier, PZQ ,5-Fu as a model drug, mixed with Huck rheometer drugs were obtained by extrusion melt method containing PZQ ,5-Fu cylindrical implant. Implant length is 10mm, a diameter of three cases, respectively, 3mm, 4mm and 8mm. Experiments established PZQ HPLC analysis methods and 5-Fu UV analysis. This paper examines the implant diameter, drug loading, and capping situation on the drug release behavior, and using SEM, XRD and GPC implants and other methods to characterize the growth of micro-release time with changes in the structure and crystallization resistance and material degradation changes. In addition, the release of the release data obtained model fit to clarify the mechanism of release. The results showed that the smaller the diameter, the faster drug release (3mm implant releasing the fastest, 8mm implants release the slowest); higher drug loading, drug release faster (50% drug loading of implants than 25% of the amount of drug release implant fast); implant capped than non-endcapped slightly slower release implant (8mm implant capped cumulative release rates than 8mm implants are not cumulative endcapped release rate). In addition, drug loading on the release behavior of the implant with the implant diameter increases. Implant releases the data most Ritger-Peppas equation, therefore, Fick diffusion is the main mechanism of drug release. Change before and after release implant implants in PZQ verified and 5-Fu release of the drug is released from the outer to inner layer by layer.
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