Preparation and in vitro characterization of berberine hydrochloride — self-emulsifying microsphere by membrane emulsification technology

This paper reports a new solid self-emulsifying drug delivery system — self-emulsifying microsphere prepared by membrane emulsification technology with the hydrophobic berberine hydrochloride as a model drug.  Solubility test and pseudo-ternary phase diagram were employed to select the optimal prescription of liquid self-emulsifying drug delivery system.  The self-emulsifying microsphere was prepared by membrane emulsification technology with the solid carrier in a gel formed by sodium alginate and calcium chloride.  The results showed that the optimal prescription of liquid self-emulsifying drug delivery system was Capmul MCM/Cremophor RH40/Labrasol/1-2propanediol = 20∶32∶32∶16.  The solid self-emulsifying microsphere had average diameter of 10.92 μm, encapsulation efficiency of 32.57% and the droplet size of reconstituted micromulsion of 156.5 nm.  Berberine hydrochloride was dispersed in microsphere in non-crystalline form.  In vitro release of the self-emulsifying microsphere showed pH response characteristics.  These results indicated that the self-emulsifying microsphere prepared by membrane emulsification technology might become a new dosage form for poorly water soluble drugs.