Aim To prepare the prolonged-released microspheres of mefformin hydrochloride. Methods Ion-exchange resin-drug mefformin hydrochloride complexes were prepared as core materials, and followed by coating using ethylcell...Aim To prepare the prolonged-released microspheres of mefformin hydrochloride. Methods Ion-exchange resin-drug mefformin hydrochloride complexes were prepared as core materials, and followed by coating using ethylcellulose （EC） by the emulsion solvent diffusion technique. The release rate of mefformin from the microcapsules was highly dependent on the encapsulating formulation, thus being used as an index for formulation screening. Orthogonal experiments were performed to optimize the coating formulation. Results The final chosen formulation for coating of mefformin microcapsules were as follows： （ 1 ） the ratio of EC （20cps） to EC （45cps） was 50：50; （2） the ratio of plasticizer to coating materials was 20% ;and （3） the ratio of resin-mefformin complexes to coating materials was 5 ： 1. Conclusion The prolonged release microspheres of mefformin hydrochloride were successfully prepared.展开更多
The film diffusion mass-transfer process of adsorption of phenol on macroporous polystyrene resin was investigated in detail In order to revise the Boyd film diffusion kinetics equation, the out-surface structure of t...The film diffusion mass-transfer process of adsorption of phenol on macroporous polystyrene resin was investigated in detail In order to revise the Boyd film diffusion kinetics equation, the out-surface structure of the macroporous resin and that of gel-type ion-exchange resin was compared and the new film diffusion equation was also suggested. These results showed that the film diffusion was influenced by porosity of the macroporous resin greatly, which differed from the film diffusion behavior of ion-exchange resin obviously.展开更多
The having-been-used-for-50-year Boyd membrane diffusion Equation-In(1 - F) = R t can be deduced into F = kt through using Maclanrin expansion equation and the Lagerange remainders. The latter is a simple membrane dif...The having-been-used-for-50-year Boyd membrane diffusion Equation-In(1 - F) = R t can be deduced into F = kt through using Maclanrin expansion equation and the Lagerange remainders. The latter is a simple membrane diffusion equation, which is available to judge if the exchanging course of the resin obeys the rules of membrane-diffusion mechanism more conveniently.展开更多
文摘Aim To prepare the prolonged-released microspheres of mefformin hydrochloride. Methods Ion-exchange resin-drug mefformin hydrochloride complexes were prepared as core materials, and followed by coating using ethylcellulose （EC） by the emulsion solvent diffusion technique. The release rate of mefformin from the microcapsules was highly dependent on the encapsulating formulation, thus being used as an index for formulation screening. Orthogonal experiments were performed to optimize the coating formulation. Results The final chosen formulation for coating of mefformin microcapsules were as follows： （ 1 ） the ratio of EC （20cps） to EC （45cps） was 50：50; （2） the ratio of plasticizer to coating materials was 20% ;and （3） the ratio of resin-mefformin complexes to coating materials was 5 ： 1. Conclusion The prolonged release microspheres of mefformin hydrochloride were successfully prepared.
文摘The film diffusion mass-transfer process of adsorption of phenol on macroporous polystyrene resin was investigated in detail In order to revise the Boyd film diffusion kinetics equation, the out-surface structure of the macroporous resin and that of gel-type ion-exchange resin was compared and the new film diffusion equation was also suggested. These results showed that the film diffusion was influenced by porosity of the macroporous resin greatly, which differed from the film diffusion behavior of ion-exchange resin obviously.
文摘The having-been-used-for-50-year Boyd membrane diffusion Equation-In(1 - F) = R t can be deduced into F = kt through using Maclanrin expansion equation and the Lagerange remainders. The latter is a simple membrane diffusion equation, which is available to judge if the exchanging course of the resin obeys the rules of membrane-diffusion mechanism more conveniently.
