| abstract |
A sustained-release preparation for oral administration containing tramadol hydrochloride suitable for administration to moderate to severe pain up to every 24 hours, wherein the preparation comprises tramadol hydrochloride in a retarding matrix, the materials selected from a) hydrophilic or hydrophobic polymers, b) digestible, long-chain substituted or unsubstituted hydrocarbons and c) polyalkylene glycols contains such that the in vitro dissolution rate of the tramadol hydrochloride preparation of the present invention is determined by the USP "Paddle" method (as described in US Pharmaceopoeia XXII, 1985) at 100 rpm in 900 ml of 0.1 N hydrochloric acid at 37 ° C and using UV Measurement at 270 nm: after 1 hour 5-50% by weight, after 2 hours 10-75% by weight, after 4 hours 20-95% by weight, after 8 hours 40-100% by weight, after 12 hours more than 50% by weight, after 18 hours more than 70% by weight, after 24 hours over 80 wt .-% is. |