Therapeutic polyanhydride compounds for drug delivery

Abstract

Polyanhydrides which link low molecular weight drugs containing a carboxylic acid group and an amine, thiol, alcohol or phenol group within their structure into polymeric drug delivery systems are provided. Also provided are methods of producing polymeric drug delivery systems via these polyanhydride linkers as well as methods of administering low molecular weight drugs to a host via the polymeric drug delivery systems.

Description

BACKGROUND OF THE INVENTION Polymers comprising aromatic or aliphatic anhydrides have been studied extensively over the years for a variety of uses. For example, in the 1930s fibers comprising aliphatic polyanhydrides were prepared for use in the textile industry. In the mid 1950s, aromatic polyanhydrides were prepared with improved film and fiber forming properties. More recently, attempts have been made to synthesize polyanhydrides with greater thermal and hydrolytic stability and sustained drug release properties. U.S. Pat. Nos. 4,757,128 and 4,997,904 disclose the preparation of polyanhydrides with improved sustained drug release properties from pure, isolated prepolymers of diacids and acetic acid. However, these biocompatible and biodegradable aromatic polyanhydrides have radical or aliphatic bonds resulting in compounds with slow degradation times as well as relatively insoluble degradation products unless incorporated into a copolymer containing a more hydrophilic monomer,...

AI Technical Summary

Benefits of technology

The present invention provides biocompatible and biodegradable polyanhydrides which serve as the polymeric backbone linking drug molecules into polymeric drug delivery systems. The polyanhydride polymers of the invention demonstrate enhanced solubility and processability, as well as degradation properties due to the use of hydrolyzable bonds such as esters, amides, urethanes, carbamates and carbonates as opposed to radical or aliphatic bonds. The polyanhydride backbone has one or more groups that will provide a therapeutically active compound upon hydrolysis. The polymers of the invention comprise one or more units of formula (I) in the backbone:

Problems solved by technology

However, these biocompatible and biodegradable aromatic polyanhydrides have radical or aliphatic bonds resulting in compounds with slow degradation times as well as relatively insoluble degradation products unless incorporated into a copolymer containing a more hydrophilic monomer, such as sebacic acid.

However, these compounds exhibit high melt and glass transition temperatures and decreased solubility, thus making them difficult to process.

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