Abstract: One aspect is a method for improved preparation of molecular imprinted polymer (MIP) particles, where initial compositions comprising insoluble MIP particles are enriched for those MIP particles that bind a particular target molecule, thus excluding non-binding and weakly binding particles from the final composition. Enrichment is typically accomplished via use of chromatographic methods capable of separating particulate material or by means of agglutination. Another aspect is preparation of improved insoluble MIPs by use of extended micronization of raw MIP particles with a view to expose a large number of binding sites per mass unit of MIP particles. In preferred embodiments the two aspects are combined. The resulting improved MIPs may be used for diagnostic, analytical and therapeutic purposes, notably as orally administered drugs which can bind substances such as cholesterol and bile acids and bile acid salts in the gastrointestinal tract.