X-Ray Diffraction (XRD)

X-Ray Diffraction (XRD) is the definitive technique for determining the crystalline structure of solid materials, providing unambiguous identification of polymorphic forms, amorphous content, and phase composition in pharmaceutical substances. When a crystalline material is exposed to X-rays, the ordered atomic lattice diffracts the radiation at angles characteristic of the crystal structure. The resulting diffraction pattern is unique to each crystalline form, much like a molecular fingerprint.

Polymorphism is a critical quality attribute in pharmaceutical drug development. Different polymorphic forms of the same API can have dramatically different physical properties including solubility, dissolution rate, melting point, and bioavailability — potentially affecting therapeutic performance. XRD is the pharmacopoeial and regulatory gold standard for polymorph identification and quantification, referenced in USP <941>, EP 2.9.33, and JP methods.

Auriga Research uses powder XRD (PXRD) for pharmaceutical polymorph screening and identification, quantitative phase analysis in API/excipient mixtures, amorphous content determination, and asbestos detection in cosmetic-grade talc. Our XRD database includes reference patterns for common pharmaceutical APIs and their known polymorphic forms.