A supersaturated drug-delivery system is capable of enhancing oral bioavailability of hydrophobic drugs. Maintenance of the supersaturated system both in vitro and in vivo is one of the most challenging parts, for that it is required to keenly understand the nucleation and crystal growth behavior. Polymers are widely used to stabilize supersaturated solutions; screening of polymers is done on the basis of their interaction with drug. Nucleation and crystal growth inhibition and drug-polymer interactions can be investigated by using various spectroscopic methods. Various formulations are prepared as supersaturated systems using different drug-delivery systems utilizing different polymers, which illustrates that supersaturation is worthwhile to increase the solubility and hence oral bioavailability of poorly soluble drugs.
Keywords: crystal growth; crystallization; drug–polymer interactions; hydrogen bond formation; nucleation; oral bioavailability; poorly soluble drugs; precipitation inhibition; stabilization; supersaturation.