ISBN : 978-93-85073-24-3 As new polymers with innovative properties became available, selection of the right polymers for certain application became critically important. This led to strong demands on more efficient and more functional drug delivery vehicles. As polymers with new properties were developed, more needs were founds to develop polymers with even more intricate properties. It is most desirable if the polymers with advanced properties are synthesized with specific functions designed for drug delivery, such as drug solubilization and drug targeting, and for solving emerging problems. For this reason, it is beneficial to understand the current drug delivery technologies and the unique roles of polymers [12]. The various forms of natural and synthetic polymers are used for drug encapsulation and to deliver compound. The chitosan, a natural and antioxidative polymer obtained from crustacean shell [13] and the synthetic polymers L-D-, and D,L- polylactic acid (PLA), polyglycolic acid (PGA), and polycaprolactic acid (PCL), polyvinyl alcohol, polyethylene glycol (PEG), poly-Nvinylpyrrolidone, etc. have been used for controlled release of drug thereby reducing unwanted side effects and improving therapy [14-17]. The formulation of nano-sized particles can be implemented to all drug compounds belonging to biopharmaceutical classification system (BCS) classes II and IV to increase their solubility and hence partition into gastrointestinal barrier [18]. Micronization is used for class II drugs of (BCS), i.e. drugs having a good permeability and poor solubility [19-21]. There are many conventional methods for increasing the solubility of poorly soluble drugs, which include micronization [22], solubilisation using co-solvents [23], salt form [24], surfactant dispersions [25], precipitation technique [26-27] and oily solution. Other techniques are like liposomes [28], emulsions [29-30], microemulsion [31-32], solid dispersion [33-34], and inclusion complexation using cyclodextrins [35-37] show sensible achiever, but they lack in universal applicability to all drugs. These techniques are not applicable for those drugs which are not soluble in aqueous and organic solvents. Nanotechnology can be used to solve the problems associated with these conventional approaches for solubility and bioavailability enhancement. Nanotechnology is a multidisciplinary scientific field undergoing explosive development. One of the greatest values/promises of nanotechnology is in the development of new and effective medical treatments, such as nanomedicine [38-39]. The early concept of nanomedicine was inspired from the idea of fabrication of nano2
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