Microparticles drug carriers

Polymeric microparticles have been studied and developed for several years. Their contribution in the pharmacy field is of utmost importance in order to improve the efficiency of oral delivery of drugs. As drug carriers, polymer-based microparticles may avoid the early degradation of active molecules in undesirable sites of the gastrointestinal tract, mask unpleasant taste of drugs, reduce doses and side effects and improve bioavailability. Also, they allow the production of site-specific drug targeting, which consists of a suitable approach for the delivery of active molecules into desired tissues or cells in order to increase their efficiency. 

The aim of this chapter is to summarize some of the research findings on xylan, a natural polymer extracted from corn cobs, which presents a promising application in the development of colon-specific drug carriers. Physicochemical characterization of the polymer regarding particle size and morphology, composition, rheology, thermal behavior, and crystallinity will be provided. Additionally, research data on its extraction and the development of microparticles based on xylan and prepared by different methods will also be presented and discussed. 

Reithmeier, H., Herrmann, J. and Gopferich, A., Development and characterization of lipid microparticles as a drug carrier for somatostatin, International Journal of Pharmaceutics, 2001, 218, 133-143. 

Z. Cui and R. J. Mumper, Microparticles and nanoparticles as delivery systems for DNA vaccines, Critical Rev. Ther. Drug Carrier Syst. 

Boisdron-Celle M, Menei P, Benoit JP. Preparation and characterization of 5-fluorouracil-loaded microparticles as biodegradable anticancer drug carriers. J Pharm Pharmacol 1995 47 108-114. 

Egito and colleagues have been working for over a decade on the extraction of xylan from corn cobs and its use for the development of microparticles as drug carriers for colon-specific delivery of anti-inflammatory and toxic drugs, such as sodium diclofenac (SD], 5-aminosalycilic acid [5-ASA], and usnic acid (UA). Xylan-coated microparticles have also been developed by Egito and co-workers in order to deliver magnetite particles [44]. Different microencapsulation techniques have been used for... 

Artursson, P., Edman, P., Laakso, T., and Sjoholm, I., 1984, Characterization of polyacryl starch microparticles as carriers for proteins and drugs, J. Pharm. Sci. 73 1507-1513. 

---