Polymers for the preparation of drug nanocrystals

Abstract

The particle size of active pharmaceutical ingredients is the primary variable controlling the bioavailability of a drug. Recently, the lower limit of processable particle size has been reduced to nanometers. Water insoluble drugs benefit from this development of nanoformulation techniques. Herein, comminution processes using various polymers whose properties span a wide range were investigated. The mean particle size of dispersion was found to depend primarily on the stabilization effect of polymeric stabilizers. For a proper combination of drug and its stabilizer, the specific interactions through functional groups and surface energy aspects need to be considered together. The polymers used in the preparation of nanocrystals should adsorb onto the surfaces of drug nanocrystals and provide steric stabilization effect. For establishing successful stabilization within a reasonable processing time, strong and fast adsorption at full coverage and a long time scale for desorption seem to be necessary in addition to steric repulsion.