Study On The Preparation Technology Of Water-in-Oil Microemulsion For Hydrophilic Drugs

The objective of this paper is to study the novel preparation technology of microemulsion for hydrophilic drugs using metformin and guaiphenesin as model drugs.Firstly, On the basis of improved pseudo-ternary phase diagrams, the effects of surfactants, co-surfactants and oils on the microemulsions were studied, and the surfactant, co-surfactant and oil used in formulation were selected. Secondly, some physical chemical parameters of a series of formulations were tested including viscosity, conductance, diameter, conductance, pH, refractive index and active energy. One the basis of these parameters and mass ratio of water loaded in microemulsion, the formulations were optimized. Thirdly, water-in-oil microemulsions for hydrophilic drugs were prepared using a novel apparatus named emulsifier. The aims of increasing the weighet percent of drugs in formulations and decreasing the mass ratio of surfactant and co-surfactant were obtained. The drug-loaded microemulsions were destroyed using NaCl saturation solution. The concentrations of drugs were tested using UV method after organic component extracted using chloroform and centrifugated with 10000rpm. The method was proved reliable and acute buy methodological average recovery.On the obtained pseudo-ternary phase diagrams of system containing tea oil/lecithin/aliphatic alcohol/water, the artifical neural network (ANN) was constructed, which can predict the phase behavior.There are some innovations in this project: the stable microemulsions were prepared using vegetable oils;the formulations were optimized buy physical chemical parameters;stability of microemulsion was quantitative described using active energy;the high drug concentration microemulsions were prepared using emulsifier; the artifical neural network of the pseudo-ternary phase diagrams.