Abstract: Compositions containing particles of biologically active agents with sizes in the micron and submicron range and methods for making and using such particles are described herein. In the preferred embodiment the biologically active agents are peptides, proteins, nucleic acid molecules, or hydrophilic synthetic molecules. The particles have a size ranging from an average diameter of about 100 nm to about 2000 nm, preferably about 200 nm to 600 nm. Optionally the biologically active agents contain a polymeric coating. The particles are formed by adding a biologically active agent to an aqueous solution, mixing a nonsolvent that is miscible with water with the aqueous solution, and precipitating particles of the biologically active agents out of the nonsolvent: aqueous solution combination. The nonsolvent is typically a C1 to C6 alcohol, preferably a C2 to a C5 alcohol. In the preferred embodiment, the nonsolvent is tert-butyl alcohol.

Abstract: Methods and compositions are provided for enhancing the bioadhesive properties of polymers used in drug delivery systems. The bioadhesive properties of a base polymer are enhanced by incorporating a short chain polymer with one or more free carboxylic groups into the base polymer to enhance the ability of the base polymer to adhere to a tissue surface such as a mucosal membrane. The short chain polymers can be incorporated within a wide range of base polymers including proteins, polysaccharides and synthetic biocompatible polymers. In one embodiment, short chain polymers can be incorporated within base polymers used to form or coat drug delivery systems, such as microspheres, which contain a drug or diagnostic agent. The short chain polymers can either be solubilized and blended with the base polymer before manufacture or else used as a coating with base polymers over existing systems.