Microparticles are spherical particles between 0.1μm and 100μm in diameter. They fall into two broad groups. Microspheres are homogenous mixtures of polymers and active ingredients, and microcapsules have a core of one substance surrounded by a shell of a different material.
Microparticles are suitable for a broad range of drug delivery applications, and they offer many advantages.
- Their small particle size offers improved reproducibility in the drug release mechanism.
- They offer improved control over the release rate of the drug.
- They present a range of options for immediate, modified, delayed, pulsed, sustained and extended release.
- They allow the preparation of dosage forms for targeted delivery through the use of coatings designed, for example, for enteric protection or colonic delivery.
- They can be easily filled into capsules.
- They can be used to manufacture high-dose suspensions suitable for preclinical toxicology programmes.
- They do not require expensive processing equipment, and so allow quick, cost effective development studies to be carried out.
- Their reduced particle size gives them the potential to improve solubility and bioavailability.
Microcapsules are particularly valuable for modified release drug delivery, and we have massed considerable expertise in their development and use. They can be formed using a range of chemical, physical-chemical and mechanical processes including coacervation, the formation of complex emulsions, meltable dispersion, pan coating, spray drying, spray congealing, centrifugal extrusion and granulation, and we are highly experienced in using these techniques and others as a basis for our formulations. Like all our services, microcapsules formulations are supplied to our clients on a royalty-free, fee-for-service basis.