ABSTRACT
The field of SMEDDS is designed to enhance bioavailability of poorly-water soluble compounds. Yet, these systems have the capacity to solubilize aqueous-based materials within its lipid matrix as L2 phase (W/O microemulsion). This characteristic is utilized in this investigation to incorporate aqueous flavors within oil vehicle as an approach to mask bitter taste of drugs. Miscibility profiles and self-micro-emulsifying regions for various lipid composites were screened by constructing ternary phase diagrams using different types of oil, cosurfactant and surfactant. Solubility of bitter taste model drug was measured in various optimized vehicles. Dynamic equilibrium phase studies were performed and phase boundaries were determined for the lipid-aqueous flavors-water systems. Self-micro-emulsifying system comprising Crodamol GTCC/ Glycerox 767HC /Croduret 40 ss at ratios of {0/80/20}, {6/54/40} or {10/40/50} have shown capacity to solubilize, aqueous-based materials including; strawberry flavor, sucrose and citric acid as L2 phase. Phase behavior study has revealed that clear dispersions can be obtained at all dilutions with water. Potential flavored self-microemulsifying lipid formulations representing type III lipid class system were developed. Aqueous flavors loaded into these vehicles can be used to mask bitter tastes in oral pharmaceuticals.
ABSTRACT
OBJECTIVE:To establish an HPLC method for the determination of the contents of Ligustrazine in rat's plasma,brain and liver.METHODS:Ligustrazine was separated on Hypersil ODS-C18 column with aspirin as internal standard.The mobile phase consisted of methanol-1.5% glacial acetic acid solution(45∶55,V/V)at a flow rate of 1.0 mL?min-1.The UV detection wavelength was 279 nm.RESULTS:The linear range of ligustrazine in rat's plasma,brain and liver was 0.006 25～7.813 ?g?mL-1,The lowest detectable limits were 0.5 ng?mL-1,1.55 ng?mL-1,and 1.55 ng?mL-1 and the average recoveries were 97.26%,96.44%,and 95.43% respectively with RSD at 3.40%,4.19% and 4.94%,respectively.CONCLUSION:With good linearity,precision and recovery,the method is sensitive and simple,and suitable for pharmacokinetic study and the research of Ligustrazine preparation.
ABSTRACT
Objective To prepare the supersaturation self-emulsifying drug delivery system(S-SEDDS) containing silymarin and to evaluate its basic properties.Methods With the time of self-emulsifying,the consequence of color visual examination and particle size as parameters,the optimum formulations of silymarin SSEDDS were screened by solubility test,compatibility tests and pseudo ternary phase diagrams.The silymarin concentration was determined by HPLC.The in vitro dissolution characteristics of silymarin S-SEDDS were investigated with silymarin SEDDS as control.Results The optimum silymarin S-SEDDS was composed of medium chain triglycerides(MCT) 40%,Cremophor RH40(ethoxylated hydrogenatedcastor oil) 48%,Labrasol 12%.The time of self-emulsifying was less than 3 min,the average particle diameter was 49.6 nm,the adding amount of hydroxypropyl methylcellulose(HPMC) was 50 mg/g,and the average content of silymarin was 39.3 mg/g.The in vitro dissolution test of silymarin S-SEDDS showed that the presence of a small amount of cellulosic polymer effectively sustained a metastable supersaturated state by retarding precipitation kinetics.Conclusion The designed formulation of silymarin S-SEDDS is reasonable and provides a strong foundation for further development of new preparations.