Application of13C NMR cross-polarization inversion recovery experiments for the analysis of solid dosage forms.
Solid-state nuclear magnetic resonance (ssNMR) is a powerful and unique method for analyzing solid forms of the active pharmaceutical ingredients (APIs) directly in their original formulations. Unfortunately, despite their wide range of application, the ssNMR experiments often suffer from low sensitivity and peaks overlapping between API and excipients. To overcome these limitations, the crosspolarization inversion recovery method was successfully used. The differences in the spin-lattice relaxation time constants for hydrogen atoms T1(H) between API and excipients were employed in order to separate and discriminate their peaks in ssNMR spectra as well as to increase the intensity of API signals in low-dose formulations. The versatility of this method was demonstrated by different examples, including the excipients mixture and commercial solid dosage forms (e.g. granules and tablets).
Faculty of Pharmacy, Medical University of Warsaw, Department of Physical Chemistry, Banacha 1, 02-093 Warsaw, Poland. Electronic address: dpisklak@wum.edu.pl.
Dariusz Maciej
DM
Pisklak
Faculty of Pharmacy, Medical University of Warsaw, Department of Inorganic and Analytical Chemistry, Banacha 1, 02-093 Warsaw, Poland.
Monika
M
Zielińska-Pisklak
Faculty of Pharmacy, Medical University of Warsaw, Department of Physical Chemistry, Banacha 1, 02-093 Warsaw, Poland.
Łukasz
Ł
Szeleszczuk
D000082:Acetaminophen / Q000032:analysis; D002227:Carbazoles / Q000032:analysis; D066241:Carbon-13 Magnetic Resonance Spectroscopy / Q000379:methods*; D000077261:Carvedilol; D002482:Cellulose / Q000031:analogs & derivatives / Q000032:analysis; D004304:Dosage Forms; D005079:Excipients / Q000032:analysis; D011412:Propanolamines / Q000032:analysis; D013012:Sorbitol / Q000032:analysis
D002227:Carbazoles; D004304:Dosage Forms; D005079:Excipients; D011412:Propanolamines; D000077261:Carvedilol; D000082:Acetaminophen; D013012:Sorbitol; C013517:ethyl cellulose; D002482:Cellulose
Cross-polarization; Inversion recovery; Solid dosage forms; Solid-state NMR