US 4,539,198 AGranted

Solid pharmaceutical formulations for slow, zero order release via controlled surface erosion: expanded range

AssigneeRowell Laboratories, Inc.

InventorsDavid R. Powell, Vithal K. Patel

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Abstract

A new class of solid pharmaceutical formulations enables the attainment of slow, zero order in vivo release of a wide range of pharmaceutically active ingredients upon oral administration. A broad range of release rates can be preselected by suitable adjustments of tablet properties. The formulations are based upon control of active ingredient release from the surface of the tablet via a controlled surface erosion mechanism. These compositions comprise: (a) an effective amount in the range of 10-90 wt. % of a pharmacologically active compound having a water solubility (20.degree. C.) of 1/5-1/1000 (w/w); (b) 1-40 wt. % of a compound which is pharmaceutically acceptable in oral compositions and has a water solubility (20.degree. C.) of 1/1-1/40 (w/w); (c) 2-20 wt. % of a compound which is pharmaceutically acceptable in oral compositions and has a water solubility (20.degree. C.) of 1/1-1/10 (w/w); (d) an amount in the range of 0.05-1.0 wt. % of a disintegrating agent for pharmaceutical compositions, at which amount the compound is ineffective as a disintegrating agent; (e) 0.1-2.0 wt. % of a surfactant which is pharmaceutically acceptable in oral compositions; and, as necessary for tablet manufacturing purposes; (f) 1-20 wt. % of a binder which is pharmaceutically acceptable in oral compositions; or (g) 0.5-5.0 wt. % of a die wall lubricant which is pharmaceutically acceptable in oral compositions.

A solid, orally administrable pharmaceutical tablet composition having an enteric coating on its surface from which the active ingredient has a slow, zero order release rate attained without layers, beads or enteric materials and without relatively insoluble polymers, waxes or gums when administered orally, said tablet being compressed to a hardness of about 5-20 kg, and being either shaped as a sphere, or else having a ratio of tablet thickness to tablet diameter effective to permit tablet erosion and penetration control sufficient for controlled surface erosion thereof, comprising an essentially homogeneous, granulated mixture of:

(a) an effective amount in the range of about 10-90 wt. % of 5-aminosalicylic acid as a pharmacologically active compound having a water solubility (20.degree. C.) of less than 1/500 to 1/1000 (w/w);
(b) about 1-40 wt. % of a surface controlling compound which is pharmaceutically acceptable in oral compositions and has a water solubility (20.degree. C.) of about 1/1-1/40 (w/w);
(c) about 2-20 wt. % of an erosion controlling compound which is pharmaceutically acceptable in oral compositions and has a water solubility of about 1/1-1/10 (w/w);
(d) an amount in the range of about 0.05-1.0 wt. %, of a surface activator which is a disintegrating agent for pharmaceutical compositions at which amount the compound is ineffective as a disintegrating agent;
(e) about 0.1-2.0 wt. % of a surfactant which is pharmaceutically acceptable in oral compositions, and, as necessary for tablet manufacturing purposes;
(f) about 1-20 wt. % of a binder which is pharmaceutically acceptable in oral compositions;
or
(g) about 0.5-5.0 wt. % of a die wall lubricant which is pharmaceutically acceptable in oral compositions;
the pharmacologically active ingredient thus having a slow, zero order release rate when administered orally, and the pharmacologically active compound not being a lithium compound, and not being penny shaped or pancake shaped wherein the ratio of thickness to diameter is too small for erosion and penetration control.

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Abstract

Claims12