抄録
The Pharmaceutical Department of Tokyo Teishin Hospital frequently encountered cases where insoluble matter formed during the preparation of paclitaxel injections. To deal with this situation, we discussed the mechanism of formation of the insoluble matter and countermeasures with the manufacturer of the drug product. Insoluble matter was observed with all paclitaxel injections examined, irrespective of the suppliers. Examination of the mechanism showed that frequent pushing-in- and- out (vertical) motions of the injection needle caused its silicone oil coating to be released and turn from white to black due to friction against the rubber stopper for the vial of the injection. The resulting matter then became inflated by the ethanol and polyoxyethylene castor oil in the injection liquid. Significant differences in the frequency of formation of insoluble matter were noted among the two manufacturers of injection needles compared, the lowest frequency being obtained from plastic injection needles. With this in mind, we selected a type of injection needle that is unlikely to produce insoluble matter, and minimized the number of vertical motions of the needle while preparing the injection. As a result, no insoluble matter formed in any of the 665 actually prepared vials. A trial assembly including an injection needle with a built-in filter also proved effective as a preventive measure against insoluble matter. In preparing an injectable drug, possible interactions with silicone oil that may be used in injection needles and syringes can lead to the formation of insoluble matter. Hence, special precautions should be exercised in the case of non-aqueous injections containing ethanol and/or polyoxyethylene castor oil.
