Preparation and Evaluation of Novel Supersaturated Solid Dispersion of Magnolol : Theme: Advancements in Amorphous Solid Dispersions to Improve Bioavailability.

This article aimed to design a new type of supersaturated solid dispersion (NS-SD) loaded with Magnolol (Mag) to raise the oral bioavailability in rats. In the light of the solubility parameters, phase solubility experiments, inhibition precipitation experiment, and in vitro release experiment, Plasdone-630 (PS-630) was selected as the optimum carrier. In addition, Mag-NS-SD was prepared by adding Monoglyceride (MG) and Lecithin High Potency (LHP) into the Mag-S-SD (Mag:PS-630 = 1:3), so as to reduce the dosage of carrier and improve the release rate. Using central composite design of response surface method, the prescription was further optimized. As the optimized condition was Mag:PS-630: MG: LHP = 1:3:0.8:0.266, the drug release rate was the fastest. Besides, after 45 min, the release rate was nearly 100%. The constructed Mag-S-SD and Mag-NS-SD were characterized by powder X-ray diffraction and infrared absorption spectrum. The XRD patterns of Mag-S-SD and Mag-NS-SD indicated that all APIs were amorphous. The IR spectra of Mag-S-SD and Mag-NS-SD demonstrated the existence of hydrogen bonding in the systems. Furthermore, in vivo pharmacokinetic study in rats revealed that compared with Mag and Mag-S-SD, Mag-NS-SD significantly increased the bioavailability (the relative bioavailability was 213.69% and 142.37%, separately). In this study, Mag-NS-SD was successfully prepared, which could improve the oral bioavailability and may increase the clinical application.

Preparation and Evaluation of Self-emulsifying Drug Delivery System (SEDDS) of Cepharanthine.

The aim of this article was to design a self-emulsifying drug delivery system (SEDDS) of loaded cepharanthine (CEP) to improve the oral bioavailability in rats. Based on the solubility determination and pseudo-ternary phase diagram, isopropyl palmitate (IPP) was chosen as the oil phase. Meanwhile, Cremophor RH40 and Macrogol 200 (PEG 200) were chosen as the emulsifier and co-emulsifier, respectively. This prescription was further optimized by using central composite design of response surface methodology. The optimized condition was CEP:IPP:Cremophor RH40:PEG 200=3.6:30.0:55.3:11.1 in mass ratio with maximum drug loading (36.21 mg/mL) and the minimum particle size (36.70 nm). The constructed CEP-SEDDS was characterized by dynamic light scattering, transmission electron microscopy, in vitro release and stability studies. The dissolution level of CEP-SEDDS was nearly 100% after 30 min in phosphate-buffered saline (PBS, pH 6.8) which was higher than that of the pure CEP (approximately 20%). In addition, in vivo pharmacokinetic study in rats showed that CEP-SEDDS dramatically improved bioavailability compared with active pharmaceutical ingredient (API) (the relative bioavailability was 203.46%). In this study, CEP-SEDDS was successfully prepared to enhance the oral bioavailability which might facilitate to increase its better clinical application. Graphical abstract.