Oral absorption of atorvastatin solid dispersion based on cellulose or pyrrolidone derivative polymers

The objectives of this study were to investigate the effects of hydrophilic polymer on the supersaturation and oral absorption of amorphous atorvastatin calcium. Solid dispersions of atorvastatin calcium were prepared by a supercritical antisolvent (SAS) process. The solid dispersion with polyvinylpyrrolidone vinyl acetate (PVP VA64) achieved a higher degree and extent of supersaturation than the dispersions prepared with water-soluble polymers such as hydroxypropylmethyl cellulose (HPMC) and polyvinylpyrrolidone (PVP K30). The absorption of atorvastatin in rats was markedly increased when atorvastatin was orally administered in a PVP VA64 solid dispersion due to enhanced supersaturation and dissolution properties. Therefore, the oral absorption of atorvastatin calcium increased with the degree of supersaturation of solid dispersions prepared using an SAS process.