Controlled Delivery of Gentamicin Using Poly(3-hydroxybutyrate) Microspheres

Lydia Francis,Tajalli Keshavarz,Ipsita Roy,Jonathan Knowles,Decheng Meng,Aldo R Boccaccini

doi:10.3390/ijms12074294

Abstract

Poly(3-hydroxybutyrate), P(3HB), produced from Bacillus cereus SPV using a simple glucose feeding strategy was used to fabricate P(3HB) microspheres using a solid-in-oil-water (s/o/w) technique. For this study, several parameters such as polymer concentration, surfactant and stirring rates were varied in order to determine their effect on microsphere characteristics. The average size of the microspheres was in the range of 2 μm to 1.54 μm with specific surface areas varying between 9.60 m2/g and 6.05 m2/g. Low stirring speed of 300 rpm produced slightly larger microspheres when compared to the smaller microspheres produced when the stirring velocity was increased to 800 rpm. The surface morphology of the microspheres after solvent evaporation appeared smooth when observed under SEM. Gentamicin was encapsulated within these P(3HB) microspheres and the release kinetics from the microspheres exhibiting the highest encapsulation efficiency, which was 48%, was investigated. The in vitro release of gentamicin was bimodal, an initial burst release was observed followed by a diffusion mediated sustained release. Biodegradable P(3HB) microspheres developed in this research has shown high potential to be used in various biomedical applications.

Highlights

Polymeric drug delivery systems are designed to deliver drugs to the local site of action for extended periods of time, so that the therapeutic levels of drugs with short in vivo half-lives can be maintained [1]
The effect of several parameters such as polymer concentration, surfactant concentration and stirring rate were investigated regarding their influence on microsphere properties, shape and dimensions
The average size of the microspheres varied from 2 μm to 1.54 μm with specific surface areas from 9.60 m2/g to 6.05 m2/g

Summary

Introduction

Polymeric drug delivery systems are designed to deliver drugs to the local site of action for extended periods of time, so that the therapeutic levels of drugs with short in vivo half-lives can be maintained [1]. Different forms of drug delivery devices are used to reduce the fluctuations in plasma drug levels, so a slower and controlled drug release rate can be achieved, which can provide an effective pharmacological response [1,2]. Microencapsulation of a drug within a polymeric device, e.g., microspheres is considered as one of the most common methods of drug delivery [3]. Drug encapsulated microspheres require less frequent drug administration when compared to the conventional dosage forms. Often the site of administration influences the performance of drug delivery due to differences in the local tissue environment such as pH and enzyme activity [3]

Methods

Results

Conclusion