Stable emulsion suitable for pharmaceutical administration, the production thereof and emulsion for pharmaceutical use
AssigneeKnoll, Inc.
InventorsKarin Schaupp, Josef Polzer, Johannes Kerbl, Kurt Lanthaler, Stanley S. Davis, Clive Washington
Life of this patent
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Abstract
A stable active substance emulsion of the oil-in-water type with a phospholipid as emulsifier is described, where the active substance dissolved in the lipid phase has one or more basic groups, is hydrophobic and oil-soluble, and has a pKa of at least 7.5, the aqueous phase is set at an acid pH, and the disperse phase gives a positive zeta potential of at least +15, but preferably +30, mV after dilution of the emulsion ready for administration to a fat content of 0.08% by weight.
Claims7
A stable emulsion which is suitable for pharmaceutical administration of the oil-in-water type, which contains in the lipid phase a hydrophobic pharmaceutical active substance, comprising
- a) a dispersed lipid phase formed by a vegetable oil, which is present in the emulsion in an amount of 5-30% by weight and is stabilized by a phospholipid as emulsifier, present in an amount of 0.5-2% by weight of the emulsion,
- b) the hydrophobic pharmaceutical active substance being present in said lipid phase, which is soluble in oil, sparingly soluble in water, strongly basic having a pKa of at least 8 and is present in the lipid phase in form of the base,
- c) an aqueous phase, which contains a physiologically tolerated buffer system, setting this aqueous phase at an acid pH and due to the low solubility in water a small amount of the active substance in ionized form,
- whereby cations of said ionized form of the active substance formed in said acid aqueous phase confer a positive charge at the interface of the emulsion, giving a positive zeta potential of at least +30 mV after dilution of the emulsion ready for administration to a fat content of 0.08% by weight.
Dependencies are inferred from the claim text.