Claims for Patent: 5,198,226

Summary for Patent: 5,198,226

Title:	Long acting nicardipine hydrochloride formulation
Abstract:	A long acting sustained release pharmaceutical composition for dihydropyridine calcium channel blockers wherein the calcium channel blocker and a pH-dependent binder are intimately admixed in essentially spherically shaped non-rugose particles of up to 1.2 mm in diameter.
Inventor(s):	MacFarlane; Calum B. (Linlitchgow, GB6), Selkirk; Alastair B. (Edinburgh, GB6), Dey; Michael J. (East Calder, GB6)
Assignee:	Syntex (U.S.A.) Inc. (Palo Alto, CA)
Application Number:	07/794,356
Patent Claims:	1. A long acting sustained release pharmaceutical composition for administration of a therapeutically effective amount of non-amorphous nicardipine hydrochloride, which comprises essentially spherical, non-coated, non-rugose particles having diameters of about 0.5 millimeters to 1.2 millimeters, comprised of about 10 to 25 weight percent of said non-amorphous nicardipine hydrochloride in intimate admixture with about 5 to 25 weight percent of a pH-dependent binder which is less soluble at lower pH and more soluble at higher pH. 2. A pharmaceutical composition according to claim 1 in which the spherical particles have an area radius to circumference radius ratio of 0.85 to 1.0. 3. A pharmaceutical composition according to claim 1 in which at least 70 weight percent of the spherical particles have diameters which are within upper and lower limits which differ by not more than a factor of the square root of two from each other. 4. A pharmaceutical composition according to claim 1 which provides therapeutic plasma concentrations suitable for twice daily administration of the pharmaceutical composition. 5. A pharmaceutical composition according to claim in which the pH-dependent binder is a single material, or a mixture of materials selected from either of the groups a and b consisting of: (a) phthalic acid derivatives of vinyl polymers and copolymers, hydroxyalkylcelluloses, alkylcelluloses, cellulose acetates, hydroxylakylcellulose acetates, cellulose ethers, alkylcellulose acetates, and the partial esters thereof; and (b) polymers and copolymers of lower alkyl acrylic acids and lower alkyl acrylates, and the partial esters thereof. 6. A long acting sustained release pharmaceutical dosage form for administration of a therapeutically effective amount of non amorphous Nicardipine hydrochloride, which dosage form consists essentially of an inert pharmaceutical carrier in which is contained: (a) a long acting pharmaceutical composition according to claim 1 for prolonged administration of non amorphous Nicardipine hydrochloride in combination with (b) a fast release pharmaceutical composition for administration of a loading dose of non amorphous Nicardipine hydrochloride, wherein the relative proportions of long acting pharmaceutical composition and fast release pharmaceutical composition are in the range of 50:50 to 100:0. 7. The pharmaceutical dosage form of claim 6 in which the inert pharmaceutical carrier is a hard gelatin capsule. 8. The pharmaceutical dosage form of claim 6 in which the pH-dependent binder is a copolymer of methacrylic acid and methacrylic or acrylic acid ethyl ester. 9. A method of treating cardiovascular disease in a mammal, which method comprises administering to a mammal in need of such treatment a therapeutically effective amount of a pharmaceutical composition of claim 1. 10. A long acting sustained released pharmaceutical composition suitable for twice daily administration of a therapeutically effective amount of nicardipine hydrochloride, which comprises essentially spherical non-coated, non-rugose particles having an area radius to circumference radius ratio of 0.85 to 1.0 and diameters of about 0.7-1.0 mm and comprising about 10-25 weight percent nicardipine hydrochloride and about 5-25 weight percent of a polymethacrylate which is substantially insoluble below 4.5, wherein at least 70 weight percent of the spherical particles have diameters which are within upper and lower limits differing by not more than the square root of two from each other.