US Patent 7569557 Compositions of estrogen-cyclodextrin complexes

Pharmaceutical compositions comprising low doses of sensitive complexes between an estrogen and a cyclodextrin are provided with improved stability. In specific embodiments the composition comprises a complex between ethinyl estradiol and β-cyclodextrin in a granulate preparation and in yet another embodiment the composition comprises a limited amount of polyvinylpyrrolidone since this excipient was found to degrade ethinyl estradiol. Furthermore, a method for improving the stability of an estrogen in a composition and for manufacturing such a stable composition is provided. Essentially, the granulate preparation are manufactured under careful control of the relative humidity.