Recent advances in materials for extended-release antibiotic delivery system

To maintain antimicrobial activity, frequent administration of conventional formulations of many antibiotics with short half-life is necessary. Otherwise, concentration under MIC occurs frequently in the course of anti-infective treatment, which induces antibiotic resistance. By maintaining a constant plasma drug concentration over MIC for a prolonged period, extended-release dosage forms maximize the therapeutic effect of antibiotics while minimizing antibiotic resistance. Another undoubted advantage of extended-release formulation is improved patient compliance. For better release properties, many materials have been introduced into the matrix and coating extended-release system in the past few years. Materials that have been widely used in industry are hydrophilic matrix materials such as hydroxypropylmethylcellulose. The excellent biocompatibility and extensive laboratory studies provide biodegradable polymers great potential for industrial applications. In addition, it seems like the researches on tailored materials that are obtained by chemical modification of the existing materials or combination of different carriers in physical mixtures have a long way to go. Meanwhile, with the development of polymers and inorganic porous nanocarriers, nanotechnology is applied increasingly for the extended delivery of antibiotics. This review highlights the development of materials used in extended-release formulation and nanoparticles for antibiotic delivery. We also provide an overview of the antibiotic extended-release products that have provided clinical benefit or are undergoing the clinical trial. The Journal of Antibiotics (2011) 64, 625-634; doi: 10.1038/ja.2011.58; published online 3 August 2011