Microbial Polyhydroxyalkanoates as Biodegradable Drug Release Materials

Abstract

The advantages of the use of controlled release systems for the delivery of bioactive species are numerous. To name a few of these, increased effectiveness of the delivery, achievement of high local concentrations of drug, increased stability of especially labile drugs, the resultant cost effectiveness of the therapy can be stated. As a result of the realisation of these advantages and the substantial increase in the number and kind of materials from which these can be constructed, the applications of Controlled Drug Delivery Systems became the hottest topic of Biomaterials and Pharmaceutical Technology fields. The delivery system almost always consists of a carrier and the bioactive species the relation of which with respect to each other determines the release behaviour. The earlier drug release systems employed synthetic polymers as the carrier and upon depletion of their drug contents there remained an empty shell or a casing which had to be disposed of, a problem if the release system employed was implanted. Development of biodegradable polymers of biological and synthetic origin led to a new wave of research. both due to new mechanisms of release which now became possible and also due to avoidance of the retrieval problem.