Drug microparticles

A pharmaceutical composition comprising microparticles of risperidone that have not been micronized by a mechanical process selected from high energy milling and high pressure homogenization, from which pharmaceutical composition essentially all of the risperidone of a sample of the composition comprising 50 mg of risperidone dissolves within not more than about 60 minutes when dissolution is measured at 37° C. with an apparatus II dissolution tester as described in the United States Pharmacopoeia operating at about 100 RPM in a medium consisting essentially of 900 mL water.

A pharmaceutical composition comprising microparticles of risperidone obtained by sublimation of a sublimable carrier from a solid solution of risperidone in the sublimable carrier.

A pharmaceutical composition comprising pharmaceutical carrier particles consisting essentially of a non-hydrosoluble material and, deposited thereon, microparticles of risperidone that are obtained by sublimation of a sublimable carrier from a solid solution of risperidone in the sublimable carrier, wherein essentially all of the risperidone of a sample of the composition comprising 50 mg of risperidone dissolves from the pharmaceutical composition within no more than about 60 minutes when dissolution is measured at 37° C. with an apparatus II dissolution tester as described in the United States Pharmacopoeia operating at about 100 RPM in a medium consisting essentially of 900 mL water.

A process for preparing a risperidone delivery vehicle comprising the steps of:

• a) forming a solid solution of risperidone and a sublimable carrier on the surface of a pharmaceutical carrier particle;
• and
• b) subliming the sublimable carrier from the solid solution to deposit microparticles of risperidone on the surface of the pharmaceutical carrier particle to obtain the risperidone delivery vehicle.