Limits of visual detection for finasteride polymorphs in prepared binary mixtures: analysis by X-ray powder...

Area of Science:

• Pharmaceutical Sciences
• Materials Science
• Analytical Chemistry

Background:

• Finasteride (FNT) exists in two enantiotropic polymorph forms (I and II).
• Polymorphism significantly impacts drug properties and efficacy.
• Accurate identification and quantification of polymorphs are crucial for pharmaceutical quality control.

Purpose of the Study:

• To establish the detection limits of finasteride (FNT) polymorphs (forms I and II) in binary mixtures.
• To evaluate the influence of experimental conditions on polymorph detection using X-ray powder diffraction (XRPD).
• To determine the minimum detectable percentage of minority phases for different XRPD equipment.

Main Methods:

• Preparation of binary mixtures of anhydrous finasteride (FNT) polymorphs (forms I and II).
• Analysis of samples using four diffractometers with varying experimental conditions, representing common drug analysis resolutions.
• Application of X-ray powder diffraction (XRPD) data and Rietveld method (RM) for phase identification and quantification.

Main Results:

• The detection limit for finasteride (FNT) polymorphs varied depending on the experimental conditions and equipment used.
• Minority phases of FNT polymorphs could be detected in proportions as low as 0.5 wt% under optimal conditions.
• High-resolution equipment and specific experimental parameters enhanced the detection sensitivity.

Conclusions:

• X-ray powder diffraction (XRPD) coupled with the Rietveld method (RM) is effective for identifying and quantifying finasteride (FNT) polymorphs.
• Understanding experimental condition-dependent detection limits is essential for accurate pharmaceutical analysis.
• The study provides valuable insights for controlling polymorphic forms in finasteride drug products.