Pharmaceutical particles

Recent developments in the discovery of new medicines have improved satisfaction as well as life expectancy of the patients suffering from diseases. Nevertheless, the physiochemical properties such as bio-availability and water solubility as well as rapid drug metabolism and clearance from blood systemic circulation have confined the optimal prescriptions of drugs at effective pharmacological dosage. Although the plasma concentration of drugs may be maintained at an appropriate level over a short period through sequential administrations, it may result in higher overall cytotoxicity and severe adverse side effects at healthy organs. Therefore, drug delivery systems (DDS) were proposed as an innovative route for the sustained and controlled delivery of drugs at pharmacological concentrations to target tissues. The DDS are micro-/nanoparticulate structures made of biodegradable and biocompatible materials, especially biodegradable polymers, which encapsulate pharmaceutical agents and release them through diffusion, degradation and erosion phenomena.