Inclusion of Lipid in the Polymeric Solid Dispersion of Lovastatin for Increased Solubility and Dissolution

Poor aqueous solubility and the subsequent bioavailability issues of orally administered drugs are getting considerable interest by formulation scientists in order to dispense hydrophobic drugs in a presentable form. Lovastatin, a model BCS class II drug, was formulated into a solid dispersion by using combination of Eudragit E100 (a hydrophilic polymer) and oleic acid (a dietary lipid). Different ratios of drug with the polymer lipid combinations were tested to probe the suitability of the dispersion. Higher oleic acid content was not suitable for the dispersions. However, presence of lipid increased the yield, and drug content. Solubility of lovasatatin significantly increased in dispersions and was dependent on the E100 concentration. Increased interaction of the drug within the lipid polymer dispersion was observed than the binary dispersions as decreased drug crystallinity, lowered drug melting point with diffused endothermic peak, and higher magnitude of structural interplay were noted when assessed by powdered X-ray diffraction (PXRD), differential scanning calorimetry (DSC), and Fourier transform infrared spectroscopy (FTIR), respectively. Dissolution studies showed that presence of lipid also prevented the recrystallization of drug but with a somewhat slower release behavior. These evaluations indicate the suitability of the inclusion of lipids in the solid dispersions for dealing with the lipophilic drug candidates.