Analysis of N-(4-hydroxyphenyl)retinamide polymorphic forms by X-ray powder diffraction

Area of Science:

• Analytical Chemistry
• Materials Science
• Crystallography

Background:

• N-(4-hydroxyphenyl)retinamide exists in multiple polymorphic forms.
• Accurate quantification of these polymorphs is crucial for pharmaceutical applications.
• Existing analytical methods may lack precision or require complex procedures.

Purpose of the Study:

• To develop a quantitative X-ray diffraction (XRD) method for analyzing N-(4-hydroxyphenyl)retinamide polymorphs.
• To establish a reliable and precise analytical technique for distinguishing and quantifying polymorphic forms I and II.

Main Methods:

• Quantitative X-ray diffraction (XRD) analysis.
• Utilized zinc oxide as an internal standard.
• Developed a standard curve correlating peak height ratio to the percentage of form I.

Main Results:

• A linear standard curve was established for the peak height ratio versus the percentage of form I.
• The developed quantitative XRD method demonstrated high precision.
• The method achieved an accuracy of within +/- 6% for polymorph analysis.

Conclusions:

• The developed quantitative XRD method is effective for analyzing N-(4-hydroxyphenyl)retinamide polymorphic forms.
• The use of zinc oxide as an internal standard provides a reliable basis for quantification.
• This precise and accurate method can be applied to quality control and formulation development.