Process for preparing crystalline ciclesonide with defined particle size

摘要

Disclosed is a process for preparing a compound of the formula I in crystalline form, a particle diameter for 50% of the total volume of all particles (X50) being in the range of from 1.8 to 2.0 micrometres, comprising the steps of a) preparation of a solution of the compound of the formula I in a suitable water-miscible organic solvent; b) adding the solution obtained as in a) to water and c) isolating the precipitate of the compound of the formula I which is formed. Also disclosed is a compound of the formula I in crystalline form having a particle diameter for 50% of the total volume of all particles (X50) in the range of from 1.8 to 2.0 micrometres. The crystalline ciclesonide forms are useful for topical application and for inhalable or nasally administered pharmaceutical preparations.