Hydrophilic-Lipophilic Drug Carrier Systems of Bead Cellulose and Isopropyl Myristate

Abstract

Solid carrier systems of bead cellulose (BC) and isopropyl myristate (IPM) as a lipophilic excipient showed high release rates for low prednisolone and high IPM content and decreasing rates for increasing drug and decreasing IPM content. The release of griseofulvin was decreased by increasing IPM content. The release was controlled by the solubility of the drugs in IPM and water, the crystalline state of the drugs, and the weight ratio of the components and was varied in a wide range by change of the prescriptions. The products were prepared according to a dispersion-coevaporation process and were received asflowable powders consisting of spherical porous particles. IPM with dispersed drug was incorporated into the pores of the beads and also precipitated on the bead surface. Depending on the ratio of IPM to drug, more or less crystalline drug particles were suspended in the liquid IPM film or the drug was amorphous dissolved. Investigations of wettability and water uptake gave hints to more lipophilic properties. The advantage of the coprecipitates was the combination of a hydrophilic carrier and a lipophilic excipient as aflowable system for controlled release.