Preferential Solvation Study of Rosuvastatin in the {PEG400 (1) + Water (2)} Cosolvent Mixture and GastroPlus...

Rosuvastatin (RST) is a poorly water-soluble drug responsible for limited in vivo dissolution and subsequently low oral systemic absorption (poor bioavailability). The mole fraction solubility values of RST in various ratios of binary mixtures "{PEG400 (1) + water (2)}" at 298.15 K were employed to investigate the preferential solvation (PS) of RST (3) by the binary components. Moreover, the GastroPlus program predicted the drug dissolution/absorption rates, plasma drug concentration, and compartmental regional drug absorbed from a conventional tablet as compared to the RST-loaded (PEG400 + water) mixture (at x ₁ = 0.5) in healthy subjects (considering the fast condition). Fedors' method was adopted to estimate the values of molar volume (314.8 cm³·mol^-1) and Hildebrand solubility parameter (28.08 MPa^1/2) of RST. The results of inverse Kirkwood-Buff integrals showed the PS of RST by PEG400 as observed in all studied ratios of the binary mixture. The highest PS value (δx _1,3 = 1.65 × 10^-2) for RST by PEG400 was attained at x ₁ = 0.5. Finally, the GastroPlus program predicted the maximum dissolution rate [20 mg within 15 min as compared to pure RST (1.5 mg within 15 min)]. Moreover, the program predicted increased in vivo oral absorption (1.2 μg/mL) and enhanced regional absorption (95.3%) of RST from upper segments of the gastrointestinal tract for the RST-loaded PEG400 + water mixture in humans as compared to conventional tablets (87.5% as total regional absorption and 0.88 μg/mL as in vivo absorption). Hence, the present binary system ferrying RST can be a promising strategy to control systemic dyslipidemia after oral or subcutaneous administration.