COMPATIBILITY OF MORPHINE, BACLOFEN, FLOXURIDINE AND FLUOROURACIL IN AN IMPLANTABLE MEDICATION PUMP

Studies were performed with a pump designed as a flow regulated implan table pump with a reservoir of 30 ml (VIP 30) for the continuous long term drug application in out-patients. The device consists of a gas dr iven two-chamber system containing the drug solution in one chamber an d the propellant in the other. At body temperature the propellant unde rlies an isobaric expansion, thus creating pressure towards the imperm eable, flexible membrane that separates the two chambers. Subsequently the pharmaceutical preparation is transported via a catheter to the t arget organ. With regard to its use as an implantable medication pump, four such devices were filled with solutions of morphine, baclofen, f loxuridine, and fluorouracil, while one blank was filled with sterile water. The stability of the solutions and their compatibility with the pump materials was then examined. With a delivery rate of 1 ml/24 h, the pump is completely emptied after 30 days. Storage was at 37 degree s C and a number of values were obtained during the twice-normal perio d of 8 weeks; the content of active substances as well as any other pr oducts that had developed was determined with an optimized HPLC method . The chromatographic separations were done with two different eluents per substance. For each substance, individual samples from different periods of time were also chromatographed for up to 1 h and scanned at different wavelengths. All four pharmaceutical solutions were found s table after 30 days, only floxuridine showed a decomposition product a fter 7 weeks' storage. A capillary regulates the rate of release by it s geometrical parameters. In a stress test, in which the substance sol ution was in contact with the capillary longer than under vivo conditi ons, there were no signs of decomposition. The study shows that the ap plication of morphine, baclofen, floxuridine and fluorouracil solution s with the medication pump VIP 30 can be recommended without reservati ons.