Comparison of the crystallinity of imipenem samples by X-ray diffraction of amorphous material.
The intensity of X-rays diffracted by amorphous material in samples of the beta-lactam antibiotic imipenem [(5R,6S)-3-[[2-(formimidoyl-amino)ethyl]thio]-6-[(R)-1- hydroxyethyl]-7-oxo-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylic acid] was used to compare the crystallinity of the samples. The method makes use of the intensity in the X-ray powder diffraction (XRPD) pattern at a diffraction angle of 28 degrees (2 theta), at which no crystalline peaks are observed. A linear relationship (R2 = 0.9999) exists between amorphous intensity and crystallinity for synthetic mixtures of amorphous and crystalline imipenem. Sample preparation techniques ordinarily used in XRPD experiments were utilized.
Crocker
L S
LS
Analytical Research Department, Merck Research Laboratories, Rahway, NJ 07065-0900, USA.
McCauley
J A
JA
D018360:Crystallography, X-Ray; D015378:Imipenem / Q000737:chemistry*; D011208:Powders
D011208:Powders; D015378:Imipenem