SOLID DISPERSION EXTENDED-RELEASE SYSTEM: A REVIEW

Solid dispersion extended-release system involves amorphization of drug material that leads to creating an alternative pathway for poorly water-soluble drugs. The drug increases solubility due to an increase in apparent solubility of the particular drug. Crystalline lattices of the drug are disturbed during its manufacture, which minimizes the crystal packing energy for solubilization. Along with this, molecular level dispersion with the carrier increases the dissolution rate. Different challenges are involved in this type of system. Supersaturation creates the separation of solute and solution, causing it to be thermodynamically unstable. Recrystallization due thermodynamically unstable state of the system causes Intramatrix recrystallization. Agglomeration, polymer hydration and clumping of the system lead to the prevention of dissolution of non-ionic, amorphous active drugs. Various manufacturing processes such as mechanical stress, downstream processing, etc., significantly impact the performance of the drug systems. Despite these issues, approaches for SDS have been used to overcome these challenges. They are based on hydrophilic polymers, hydrophobic polymers, wax, and lipids systems. At present, the perfect SDS isn’t readily available, but with precision and proper formulation, reprecipitation of SDS can be avoided, which can improve bioavailability issues in society.