Abstract
In modern medicine technologies the oral administration of solid forms is the preferred route for drug delivery. Thus, in pharmaceutical applications, size, shape and morphology of the solid particles are important because they can affect the solubility as well as bioavailability of the drug particles. Since the bioavailability of orally applied drugs depends on the rates of dissolution and absorption, methods to increase such rates are often essential to reach significant levels (concentrations) in the blood. A very suitable way to increase the rate of dissolution is the reduction of the particle size. Particle design, in particular the design of micron, submicron, or nanoparticles, is thus critical. There are several methods for the production of drug particles of decreased sizes such as pulverization of large particles using a ball or jet mill, solidification of emulsions by in-water drying methods, spray freezing, spray drying and supercritical antisolvent technique (SAS), etc. These methods are reviewed here with a focus on the production of micro/nano-sized drug particles with or without water soluble materials. Such particles are used in oral, pulmonary and transdermal drug delivery of water insoluble or poorly water soluble drugs. Especially, our review concentrates on spray drying methods for the synthesis of drug particles with or without water soluble materials that show a faster rate and higher extent of dissolution and enhanced bioavailability in comparison with commercial preparations containing the normal form of the drug. This review provides an update and insights on recent and relevant studies in this area, highlights our work in this field and attempts to provide a future outlook on this research.
Keywords: Bioavailability, drug delivery, dissolution, microparticles, nanoparticles, poorly soluble drugs, preparation technologies
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