GB2352172A — Orally administered dose unit comprising a drug with an outer coating of an enteric polymer, which allows co-administered food to separate from the dose unit

USPTO Abstract

An orally administrable pharmaceutical dose unit, such as a tablet or capsule, has a size greater than 7 mm and comprises a drug and an outer coating, which coating comprises a polymer material that is insoluble in aqueous solutions with a pH below 4.0 (ie under the acid conditions present in the human stomach). By appropriate selection of the components and thickness of the coating, it is possible for such dose units to be retained intact within the stomach, following their co-administration with a meal, with the dose unit only breaking up to release the drug contained therein when the bulk of the food has emptied into the small intestine. The coating is thus adapted to provide a separation of the dose unit from co-administered food material and disintegration of the dose unit in the stomach, thereby reducing adverse interaction between drug and food. A fail-safe mechanism is provided when the polymer begins to dissolve at a higher pH that is typical of the small intestine (ie pH 5.0 and above). Prefered polymers are enteric polymers such as cellulose acetate trimellitate (CAT), hydroxypropylmethyl cellulose phthalate (HPMCP), polyvinyl acetate phthalate (PVAP), cellulose acetate phthalate (CAP), ethyl cellulose and enteric methacrylic acid copolymers (such as 1: 1 copolymer of methacrylic acid and ethyl acrylate). Suitable drugs for use in the dose units include amoxicillin, ampicillin, antipyrine, clodronate and other similar bisphosphonates, ACE inhibitors such as captopril, cilazipril, enalapril, fosinopril, lisinopril, mocxipril, perindopril, quinapril, ramipril and trandolapril, cephalexin, ketoconazole, oxytetracycline, tetracycline, levodopa, methyldopa, methacycline, nafcillin, penicillamine, rifamycin, theophylline, peptidomimetic thrombin inhibitors, such as sampatrilat, and the peptide inhibitor LY303496.