Substantially pure fluorescein
AssigneeAlcon Manufacturing, Ltd.
InventorsGregory Bydlinski, Robert Gregg Harris, Britt S. Scott
Life of this patent
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Abstract
The present invention is directed to an improved process for producing substantially pure fluorescein, as well as to substantially pure fluorescein compositions prepared by the process. The invention is particularly directed to the provision of pharmaceutical compositions for use in angiography. The substantially pure fluorescein produced by the process of the present invention is low in color, low in sodium chloride content, and substantially free of pyridine.
Claims23
A composition comprising substantially pure fluorescein.
A process for preparing substantially pure fluorescein which comprises:
- (a) hydrolyzing diacetylfluorescein to form fluorescein;
- (b) adding charcoal to the fluorescein in solution to form a fluorescein/charcoal mixture;
- (c) filtering the fluorescein/charcoal mixture;
- (d) adding ethanol to the filtrate;
- (e) adjusting the pH using an acidic solution to form a precipitate;
- (f) filtering;
- and (g) washing.
A method of determining the purity of a fluorescein composition which comprises:
- (a) obtaining a high-pressure liquid chromatogram of the composition;
- (b) identifying peaks in the chromatogram corresponding to related-substance impurities;
- and (c) taking area measurements of the peaks to determine a relative concentration thereof.
A pharmaceutical composition for use in angiography, comprising substantially pure fluorescein and a vehicle for injection.
A composition comprising substantially pure fluorescein prepared by deacetylation of diacetylfluorescein.
Dependencies are inferred from the claim text.