ABSTRACT
Apart from the treatm ent of local diseases, nasal drug delivery has caught attention of formulation scientists since long for direct delivery to brain as well as systemic delivery not only of small drug molecules but also of proteins and peptides. The classical advantages of nasal drug administration, such as ease of local treatment, enhancing bioavailability of proteins and peptides, direct brain delivery, and evasion of unwanted adverse effects associated with other routes of administration, have been further augmented by nanosystems which also avail us with the possibility of providing controlled release of drugs, modifying the formulation for targeted delivery, and protecting the therapeutic agent. The choice of materials used to formulate nasal nanosystems is often influenced by toxicity, biodegradability, biocompatibility, and ease of manufacture
for ultimate application. Polyesters have shown their potential in nasal drug delivery to fit the criteria of biodegradability, nontoxicity, and ability to control drug release through co-polymerization with other polymers of same or different nature at various degrees to suit the biological needs. Several polyester polymers have evolved in drug delivery with copolymer of lactic acid and glycolic acid already approved by USFDA for drug delivery application. Therefore, further explorations of polyester nanosystems in nasal drug delivery will extend the clinical applicability and provide better treatm ent alternatives in future. In this chapter, the physicochemical diversity of polyesters and methods of preparation of polyester nanosystems have been detailed with further discussions on the drug delivery applications of these nanosystems, giving emphasis on the influence of their physicochemical properties.
