The present invention relates to a
solid, oral pharmaceutical composition comprising naloxone, or a pharmaceutically acceptable salt thereof as the
active ingredient, the composition having a delayed release of said
active ingredient. The composition can comprise a matrix containing
glycerol di-
behenic acid esters as matrix formers, with a
mass ratio of naloxone to matrix former(s) of between 1:1 and 1:10, whereby the
active ingredient naloxone has a delayed release. According to the invention, in order to provide a composition suitable for a dosage covering at least twelve hours for treating
opioid-induced obstipation, the composition has an in-vitro release rate of the active ingredient, measured using a vane stirrer method according to Eur. Ph. at 75 U / min in 500 ml of 0.1 N
hydrochloric acid at 37 DEG C, of 0 % to 75 % in 2 h, 3 % to 95 % in 4 h, 20 % to 100 % in 10 h, 30 % to 100 % in 16 h, 50 % to 100 % in 24 h and more than 80 % in 36 h, said composition having an IC50 / Cmax value of at least 40. Preferably, the composition comprises a value for tmax (naloxone) / tmax (naloxone-3-glucuronoid) of at least 5. In an alternative embodiment, the composition can take the form of a multi-layer tablet.