Microspheres are an optimal drug delivery system due to their ability to encapsulate various drugs, biocompatibility, high bioavailability, and sustained drug release characteristics. They have been used in pharmaceuticals for decades, specifically in the fields of cancer therapy and tissue engineering. Intensive research and development has yielded enormous dividends in microsphere production, enabling more precise control over critical characteristics, including size, shape, drug release, and targeting capabilities. This has led to continued innovation in microsphere-based drug delivery systems, offering greater therapeutic efficacy and improved patient outcomes.
Advancements in In Vitro Release-Testing Methods
In vitro release-testing methods are crucial for microsphere development. Several methods, including sample and separate, dialysis membrane sacs, and USP apparatus IV, have been used for in vitro release-testing. Currently, USP apparatus IV is the method of choice. Accelerated in vitro release tests have been developed to shorten the testing time for quality control purposes. In vitro-in vivo correlations using real-time and accelerated release data have been developed to minimise the need for in vivo performance evaluation.
Developments in Testing and Storage Stability of Microspheres Containing Large Molecules
Microsphere storage stability studies have been conducted to investigate the influence of various environmental factors on microsphere quality throughout the product shelf life. New tests, including the floating test and the in vitro wash-off test, have been developed, along with advancements in characterisation techniques for other physico-chemical parameters such as particle size, drug content, and thermal properties. However, there is still a lack of guidance in the area of microsphere release testing. Microsphere storage stability studies should be extended to include microspheres containing large molecules.
Prolonged Release and Targeting of Anticancer Drugs to Tumours
Microspheres have received much consideration in the field of oncology due to their ability to target anticancer drugs to tumours. Microspheres are typically free-flowing powders consisting of synthetic, biodegradable polymers. They are spherical microparticles and are used where reliable and expected particle surface area is vital. The microsponge drug delivery system (MDS) is an innovative and unique way of delivering drugs in a structured manner. Using microsponge drug delivery, regulated drug delivery may now be achieved quickly and easily.
Breakthroughs in Microsponge Technology
Microsponge drug delivery systems have revolutionised drug delivery by providing a structured approach to regulated drug delivery, ranging in size from 5 to 300 microns, with a large porous structure and a very tiny spherical shape, MDS comprises porous microspheres. Although MDS is primarily used to deliver drugs via topical channels, they have recently shown potential for drug delivery via oral, ophthalmic, and parenteral routes. By modifying the pharmaceutical release contour and improving formulation stability while minimising the negative impact of the drug, MDS can greatly benefit drug delivery. Additionally, the most important attribute of MDS is its capacity to self-sterilize.
Interested in Microsphere Developments?
Microspheres have emerged as promising drug delivery systems due to their unique characteristics, biocompatibility, high bioavailability, and sustained drug release. Recent advancements in in vitro release-testing methods, testing and storage stability of microspheres containing large molecules, prolonged release and targeting of anticancer drugs to tumours, and breakthroughs in microsponge technology have helped improve the efficiency and efficacy of microspheres. With continuous advancements in this field, microspheres are expected to find a central place in novel drug delivery, particularly in diseased cell sorting, diagnostics, gene and genetic materials, safe, targeted and effective in vivo delivery, and supplements as miniature versions of diseased organs and tissues in the body.
Powder Systems Limited is committed to designing and engineering advanced technology to support the process development of microspheres, providing fit-for-purpose solutions for our clients and partners. We are proud to be at the forefront of the latest breakthroughs in pharmaceutical microspheres, and we look forward to continuing to support the development of these innovative drug delivery systems.