The effect of controlled osmotic stress on release and swelling properties of a water-in-oil emulsion.
The purpose of this study was to investigate the effect of osmotic gradients in a water-in-oil (w/o) emulsion on release properties in order to control the release of hydrophilic drugs. The magnitude and direction of the osmotic gradient was shown to have a pronounced effect on the apparent permeability of the hydrophilic marker, [3H]glucose. The apparent permeability coefficient of glucose could be varied between 1.0x10(-5) and 5.0x10(-8) cm s-1 using osmotic gradients. The release rate of glucose was related to the swelling properties. The larger the degree of swelling, the lower the release rate. Furthermore the present w/o emulsion has a low viscosity and a long-term physical stability. This makes the emulsion a promising parenteral drug delivery system in which the release of hydrophilic drugs such as peptides, can be controlled.
Bjerregaard
S
S
Department of Pharmaceutics, The Royal Danish School of Pharmacy, Universitetsparken 2, DK-2100, Copenhagen O, Denmark.
Söderberg
I
I
Vermehren
C
C
Froekjaer
S
S
D004655:Emulsions; D005947:Glucose / Q000378:metabolism; D009997:Osmotic Pressure
D004655:Emulsions; D005947:Glucose