The characteristics and mechanism of co-administration of lovastatin solid dispersion with kaempferol to increase oral bioavailability

Design and Development of Solid SMEDDS and Liquisolid Formulations of Lovastatin, for Improved Drug Dissolution and In vivo Effects-a Pharmacokinetic and Pharmacodynamic Assessment

Lovastatin (Lov) is a lipid-lowering agent, with 5% bioavailability (BA) due to extensive first pass metabolism and poor solubility. To enhance dissolution and in vivo effects, Lov solid self microemulsifying drug delivery system (SMEDDS) and liquisolid systems were developed and evaluated to select superior one. Solubilities were determined in oils, surfactants, and cosurfactants. Ternary phase diagrams were constructed and selected the one which showed maximum emulsion zone. In vitro dissolution, DSC, SEM and PXRD studies were used to characterize the developed formulations. In vivo studies were conducted on optimal formulations in wistar rats. Based on solubilities, Capmul PG8 and Capmul MCM were preferred as oils, Labrasol and Transcutol P as surfactant and cosurfactant. Here, Syloid XDP carrier showed better adsorption capacity among others, hence was used in optimal solid SMEDDS (SX) and liquisolid (LS) formulations. Dissolution study results showed significant improvement in release when compared to pure drug. DSC, SEM, and PXRD results indicated the loss of drug crystallinity in optimal formulations. In pharmacokinetic (PK) study, SX and LS showed 2.57 and 1.43 fold improvements in AUC, when compared to that of coarse suspension (CS). In pharmacodynamic (PD) study, hyperlipidemia was induced by Triton X-100. CS and LS treatments showed a decline in hyperlipidemic levels at 4 h. But, SX-treated group showed early onset of decline at 2 h. Further, the duration of anti-hyperlipidemia was at least 12 h extra when compared to CS and LS. This study confirmed the superiority of SX over LS in PK and PD effects.

Solubility and Bioavailability Enhancement of Oridonin: A Review

Oridonin (ORI), an ent-kaurene tetracyclic diterpenoid compound, is isolated from Chinese herb Rabdosia rubescens with various biological and pharmacological activities including anti-tumor, anti-microbial and anti-inflammatory effects. However, the clinical application of ORI is limited due to its low solubility and poor bioavailability. In order to overcome these shortcomings, many strategies have been explored such as structural modification, new dosage form, etc. This review provides a detailed discussion on the research progress to increase the solubility and bioavailability of ORI.