The present invention relates to solid oral formulations comprising a compound of formula (3Z,5S)-5-(hydroxymethyl)-1-[(2′-methyl-1,1′-biphenyl-4-yl)carbonyl]pyrrolidin-3-one-O-methyloxime, and/or an active metabolite thereof, and the use of said formulations in the treatment and/or prevention of preterm labor, premature birth, dysmenorrhea and embryo implantation failure due to uterine contractions. The present invention is furthermore related to processes for their preparation.