Solid Dispersion - a Novel Approach for Enhancement of Bioavailability of Poorly Soluble Drugs in Oral Drug Delivery System

It has been estimated that nearly 35-40 % of drugs suffer from poor aqueous solubility and it affects the absorption of drug from gastrointestinal tract that leads to high inter and intra subject variability, poor oral bioavailability, increase in dose, reduction in therapeutic efficiency and finally failure in formulation development. Various formulation strategies like micronization, solubilization, complexation, dendrimers for drug solubilization, formation of solid solutions/dispersions with hydrophilic carriers, self-micro emulsifying drug delivery systems (SMEDDS). Nanoparticulate approaches, spray drying, pro-drug approaches and salt synthesis had been attempted for solubility enhancement. An attractive possibility would be represented by implementing a simple solid dispersion technique by utilizing several hydrophilic carriers. Such technique impart a means of reducing particle size to a nearly molecular level, presenting a variety of processing and excipients options which allow for flaccidity when formulating oral delivery systems of low water soluble drugs with cost effectiveness and denoting dose reduction [1].