Patent ID: 11918590
Assignee: INTAS PHARMACEUTICALS LTD.
Field: Pharmaceuticals (Chemistry)
Classification: CPC A | IPC A

Claim 2:
3. A stable extended release pharmaceutical composition of Clozapine with one or more pharmaceutically acceptable excipients, comprising: a) granules, pellets, beads or spheroids comprising Clozapine with pharmaceutically acceptable excipients, b) a first seal coat layer comprising a hydrophilic polymer, c) an acidic coating comprising an acidic substance, d) a second seal coat layer comprising a hydrophilic polymer, (e) an extended release coating with a water insoluble polymer and a water soluble polymer, and (f) a third seal coat layer comprising a hydrophilic polymer;
wherein, the amount of the seal coating in the composition is from 2-20%; the amount of the acidic coating in the composition is from 20-40%; the amount of extended release coating in the composition is from 2-20%;
wherein, the hydrophilic polymer comprises hydroxypropyl methylcellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxyethyl methylcellulose, carboyxmethylcellulose, polyethylene glycol, polyethylene oxides, or polyalcohols; the water insoluble polymer comprises Chitosan, polyurethanes, ethyl cellulose, cellulose acetate or waxes; the water soluble polymer comprises hydroxypropyl methylcellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxyethyl methylcellulose, carboxymethylcellulose, polyethylene glycol, polyethylene oxides, or polyalcohols,
wherein the total impurities in the said pharmaceutical composition is not more than 2% w/w of Clozapine and wherein an assay of the quantity of Clozapine in the said pharmaceutical composition is from 95% to 105% upon storage at 25±2° C. and 60±5% RH for 6 months, relative to the quantity of Clozapine in the pharmaceutical composition prior to storage; and
wherein the said composition comprises Clozapine having an effective particle size (D90) of less than about 10 micron that provides solubility of Clozapine of at least 20 mg/ml in 0.1N hydrochloric acid.