Patent ID: 8748447
Filing Date: 2014-06-10
Classification: A61K,A61P,C07D

Abstract:
1. A process for the preparation of rifaximin powder having an X-ray diffraction spectrum corresponding to an amorphous form, having a particle size between 40 and 120 micrometers in a percentage of 90% of the total particles as determined by using a Beckman-Coulter LS 100 Q particle size analyzer equipped with a micro-volume cell, and a bulk density between 0.1 and 0.5 g/ml as determined by using a 10 ml volumetric flask, characterized by the steps of: a) Solubilisation of crystalline or amorphous rifaximin, or their mixture, in organic solvents or their mixtures; b) Spraying of said solution in fluid bed apparatus at a pressure comprised between 0.5 and 2.5 bar under a flow of warm air; c) Drying the solid rifaximin until constant weight at temperature comprised between 20° C. and 120° C.