Adsorption Thermodynamics and Kinetics of Enramycin on XAD-16 Macroporous Resin / 中国药学杂志

OBJECTIVE: To investigate the adsorption thermodynamics and kinetics of enramycin on XAD-16 macroporous resin. METHODS: Series of static adsorption experiments were carried out. The adsorption equilibrium data were fitted to Langmuir and Freundlich isotherm equations, which could describe the adsorption behavior of enramycin on XAD-16 macroporous resin. The thermodynamic properties were described by thermodynamic parameters. Then, pseudo-first-order model and pseudo-second-order model were applied to describe the kinetics of adsorption process. RESULTS: The adsorption equilibrium data were agreed with Langmuir isotherm well. Thermodynamic analysis suggested ΔH<0, and ΔG<0, which indicated the adsortion procedure was a spontaneously exothermic reaction with entropy decrease. The adsorption of enramycin on XAD-16 macroporous resin could be described well by Pseudo-second-order model. CONCLUSION: The adsorption thermodynamics and kinetics of enramycin on XAD-16 macroporous resin can supply the theory for the separation and purification of enramycin on XAD-16 macroporous resin.

Preparation and quality evaluation of enramycin self-microemulsifying drug delivery system / 中国药学杂志

OBJECTIVE: To prepare enramycin self-microemulsifying drug delivery system (SMEDDS) and evaluate its quality. METHODS: The formulations of enramycin SMEDDS were screened by solubility experiment and self-emulsifying grading test. The formulation was optimized using Design Expert Software, taking particle size as dependent variable and the usage amoumts of oil, surfactant, and cosurfactant as independent variables. RESULTS: The optimized formulation of enramycin SMEDDS consisted of 20% ethyl oleate, 40% RH40, and 40% 1,2-propylene glycol. 1.0 g mixture contained 20 mg enramycin, which dispersed rapidly into water and the particle size of the formed emulsion was (27.81±0.79)nm. The enramycin SMEDDS dissolved by more than 90% within 10 min, much faster than that of enramycin API. The particle size and concentration of SMEDDS were stable at alternative temperature cycles (4 and 40℃) for 48 h, and the SMEDDS formulation had no effect on the bacteriostasis of enramycin. CONCLUSION: The quality of enramycin SMEDDS is stable. The system increases the dissolution of enramycin significantly and could be advantageous to improve the oral bioavailability of enramycin.