Method of producing drug-containing wax matrix particles, extruder to be used in the method and sustained-release preparation containing cilostazol

摘要

It is intended to provide a method of conveniently producing drug-containing wax matrix particles (in particular, drug-containing wax matrix particles having an average particle diameter of 1 mm or less) through melting and spraying steps without suffering from a jamming failure caused by the recrystallization of the once molten drug. Namely, drug-containing wax matrix particles containing a drug and a wax are produced via the following steps (i) and (ii): (i) the step of feeding the drug and wax as described above into an extruder wherein the temperatures of a barrel (1) and a die have been controlled to a level higher than the melting point of the wax; and (ii) the step of melt-kneading the drug with the wax in the extruder as described above and simultaneously spraying out the melt-kneaded mixture comprising the drug and the wax from a spray nozzle (5), which is attached directly to a die (3) provided at the tip of the barrel (1) in the extruder, into an atmosphere at a temperature lower than the melting point of the wax to thereby form particles.