Method for casting dissolvable ophthalmic shields in a mold
AssigneeChiron Ophthalmics, Inc.
InventorsCary Reich, Jean Toner-Webb
Life of this patent
Estimating the term…
Abstract
A method for making a biosoluble collagen or gelatin ophthalmic shield, which optionally contains a pharmaceutically active agent, by casting collagen or gelatin in a mold; chilling the mold with the collagen or gelatin shield until the shield is strong enough to allow the mold to be opened without deforming the shield in one half of the mold; drying the collagen or gelatin shield while it is still in the mold; and then cross-linking the collagen or gelatin shield to achieve the desired solubility. The resulting shield can be worn comfortably in the eye and leaves no observable material after complete dissolution and drug release.
Claims24
A method of casting a dissolvable ophthalmic shield, comprising the steps of:
- a. forming a viscous collagen and/or gelatin gel;
- b. placing the gel in a double-sided mold;
- c. closing the mold to cast the gel into the form of a shield;
- d. chilling the mold to a temperature sufficiently low to effect sufficient dimensional stability and to allow separation of the mold halves without deforming the shield;
- e. opening the chilled mold while leaving the shield in one portion of the mold;
- f. drying the shield;
- and
- g. partially cross-linking the shield to obtain a shield that dissolves under physiological conditions in the eye.
A method of casting a dissolvable collagen shield comprising the steps of:
- a. forming a viscous collagen gel having a collagen concentration of about 10% by weight of the gel;
- b. incorporating fillers therein to give the desired swell and properties;
- c. centrifuging the collagen gel for about 5 to 10 minutes at about 4.degree. C. to about 15.degree. C. at about 3,000 to about 13,000 rpm to form a semi-clear collagen gel free of bubbles;
- d. placing a drop of the collagen gel on the female half of a double-sided mold;
- e. casting the collagen shield by placing the complementary male half of the double-sided mold onto the female half with the collagen gel and compressing the two halves together forming a collagen shield;
- f. chilling the double-sided mold with the collagen shield in liquid nitrogen to effect dimensional stability to the collagen shield;
- g. separating the two halves of the double-sided mold while leaving the collagen shield in one portion of the mold;
- h. drying the collagen shield by air drying at from about 4.degree. C. to about room temperature followed by vacuum desiccation to allow reproducible properties;
- and
- i. partially cross-linking the collagen shield by employing a sufficient amount of UV light to obtain a collagen shield that dissolves under physiological conditions in the eye and can be placed on an eye.
Dependencies are inferred from the claim text.