Anhydrous crystalline form II of 17α-acetoxy-21-methoxy-11β- [4-N, N-dimethylaminophenyl] -19-norpregna-4,9-diene-3,20-dione characterized by providing one or more of: a) have characteristic powder X-ray diffraction peaks at approximately 6.8, 11.0, 11.6, 14.9, 19.1 ± 0.2 [°] 2Θ； b) have characteristic Raman TF absorption bands at approximately 3054, 2963, 2850, 1604； 1195, 1159 ± 4 cm -1； c) have a solid state 13C NMR spectrum comprising characteristic resonances at approximately 196.7, 172.4, 169.3, 20.7, 20.1, 17.7 ± 0.1 ppm.Forma cristalina II anhidra de la 17&alpha；-acetoxi-21-metoxi-11&beta；-[4-N,N-dimetilaminofenil]-19-norpregna-4,9- dieno-3,20-diona caracterizada por que proporciona una o más de: a) tener picos de difracción de rayos X de polvo característicos a aproximadamente 6,8, 11,0, 11,6, 14,9, 19,1 ± 0,2 [°] 2&Theta；； b) tener bandas de absorción Raman TF características a aproximadamente 3054, 2963, 2850, 1604； 1195, 1159 ± 4 cm-1； c) tener un espectro RMN de 13C en estado sólido que comprende resonancias características a aproximadamente 196,7, 172,4, 169,3, 20,7, 20,1, 17,7 ± 0,1 ppm.
