Oral Solid Solution Formulation of a Poorly Water-Soluble Active Substance

A method of preparing an oral immediate release formulation of a poorly water-soluble biologically active substance with enhanced bio-availability, wherein said formulation is a homogeneous and thermodynamically stable solid solution comprising as a percentage of the total weight of the formulation:

• a) up to 50% by weight of a compound corresponding to formula (I):
• wherein:
• R1 is selected from the group consisting of (C1-C6)alkoxy(C1-C6)alkyl which may be substituted by a (C1-C6)alkoxy, phenyl-(C1-C6)-alkyl and phenyloxy-(C1-C6)-alkyl wherein the phenyl group may be substituted with (C1-C6)alkyl, (C1-C6)alkoxy or halogen, and naphtyl-(C1-CG)-alkyl,
• R2 and R3 are each independently hydrogen or halogen,
• R4 is a biolabile ester forming group,
• M is a metal ion,
• A is CH2, and
• n is 1, 2 or 3;
• b) from 20 to 70% by weight of a non-ionic hydrophilic surfactant which is liquid between 15 and 30° C.;
• and
• c) from 5 to 70% by weight of a pharmaceutically acceptable organic polymer or polymer mixture which is liquid above 60° C. and solid below 30° C.;
• said method comprising:
• a) mixing the non-ionic hydrophilic surfactant with the pharmaceutically acceptable organic polymer or polymer mixture at between 50-100° C.;
• b) adding the compound of formula (I) to the mixture from a) and dissolving the compound of formula (I) in the mixture from a) at said temperature;
• and
• c) solidifying the mixture from b) at room temperature.