Measurement with VT-RH chamber
H. Petrickova
Zentiva a.s., U kabelovny 130, 102 37 Praha 10 – Dolní Měcholupy, Česká Republika
Email: hana.petrickova@zentiva.cz
Keywords: XRPD, pharmaceuticals, nonambient, moisture sorption
Powder
diffraction patterns are the most fundamental, yet crucially important;
application of XRPD is in identification or “fingerprinting” of crystalline
phases in pharmaceutical industry[1]. Function of temperature and/or
relative humidity can provide a direct means of characterizing the stability of
a pharmaceutical material at defined temperature and relative humidity and the
occurrence of hydration/dehydration processes[2]. Such a non-ambient
diffraction experiments can be performed at any stage of the drug development
process (API production, stability testing, formulation, storage…) to avoid
further complications.
The object
of presented study is to demonstrate the possible utilization of variable
temperature and relative humidity XRPD to investigate hydration/dehydration
process of the pharmaceutical material.
The
behaviour of pharmaceutical hydrates has become the object of increasing
interest over last two decades, primarily due to the potential impact of
hydrates on development process and dosage form performance. Hydration of the
material also plays a role in bioavailability, influences dissolution, hardness
of tablets or even processability. Interconversion between polymorphs and
hydrates may occur as a function of temperature or of relative humidity or of
both. During and after manufacturing even air moisture from the environment may
change the hydration state of API in dosage form.
X-ray diffraction system with variable temperature and relative humidity was used. Instrumentation as well as obtained results will be discussed. The potential for interconversion during development was studied. Just different powder diffraction patterns can be used as an evidenced of change in the structure. Anyway, DSC and IR were used as complementary techniques to XRPD.
1. J.Bernstein: Polymorphism in molecular crystals, IUCr Monographs on Crystallography – 14, Oxford University Press, 2002.
2. H.G.Brittain: Polymorphism in Pharmaceutical Solids, Marcel Dekker, Inc. 1999