TITLE:
Quantifying Isotibolone in Raw Materials of Tibolone
AUTHORS:
Selma Gutierrez Antonio, Ariel Gomes, Fábio Furlan Ferreira, Gabriel L. B. Araujo, Carlos O. Paiva-Santos
KEYWORDS:
Hormones; Rietveld Method; X-Ray Powder Diffractometry; Synchrotron Radiation; Quantitative Phase Analysis
JOURNAL NAME:
Pharmacology & Pharmacy,
Vol.4 No.3,
May
31,
2013
ABSTRACT: Tibolone, a synthetic steroid, is used in the
treatment of natural or surgical menopause disturbs resultant of estrogenic
deficiency. Isotibolone (Δ4-tibolone) is one of the three active
metabolic degradation products of tibolone that displays progestagenic effects
on carcinoma cell growth and gene regulation. Isotibolone can be present in raw
material of tibolone due to some
inadequate synthesis or storage. Its presence is necessary to be identified and
quantified in active pharmaceutical ingredients (API), before its use in the
manufacturing of medicines. After a recent study on the crystal structure
determination of isotibolone, quantitative phase analyses of both tibolone and
isotibolone in raw materials and tablets became possible to be conducted. X-ray
powder diffraction is one recommended tool for this purpose, but it can be
highly frustrating due to the extreme peak overlap when conventional laboratory
equipments are used. In this work we show that the use of Brazilian Synchrotron
Light Source X-ray powder diffraction data and the Rietveld method can be
successfully applied to identify and quantify the isotibolone in two samples of
tibolone raw materials.