Abstract

MICROSPHERES FOR SUSTAINED RELEASE FORMULATIONS: AN EXTENSIVE REVIEW

Aditya Naik*, Dr. Arun Patel, Shailendra Patel

Abstract

The continuous advancement in pharmaceutical technology has led to the development of novel drug delivery systems aimed at overcoming the limitations associated with conventional dosage forms, such as frequent dosing, fluctuating plasma drug concentrations, poor bioavailability, and reduced patient compliance. Sustained-release drug delivery systems (SRDDS) are designed to release drugs at a controlled rate over an extended period, thereby maintaining therapeutic drug levels for prolonged durations. Among various controlled drug delivery carriers, microspheres have gained considerable importance due to their ability to provide sustained, predictable, and controlled drug release. Microspheres are solid, spherical particulate systems generally ranging from 1 to 1000 μm in size and are formulated using biodegradable or non-biodegradable polymers. The drug may be uniformly dispersed within the polymeric matrix or encapsulated within a core-shell structure, allowing modulation of drug release kinetics. Microsphere-based formulations offer several advantages, including reduced dosing frequency, improved bioavailability, enhanced drug stability, minimized adverse effects, and improved patient compliance. Their multiarticulate nature also reduces the risk of dose dumping and ensures uniform distribution within the gastrointestinal tract. This review provides an extensive overview of microspheres used in sustained-release drug delivery, covering their classification, polymers employed, methods of preparation, drug release mechanisms, characterization techniques, therapeutic applications, recent advancements, limitations, and future prospects, highlighting their growing significance in modern pharmaceutical development.

Keywords: Microspheres; Sustained-release drug delivery; Controlled drug delivery systems; Polymeric microspheres; Biodegradable polymers; Drug release kinetics; Multiarticulate systems.