Fosinopril sodium

As mentioned before, fosinopril sodium is known to be capable of existing in two polymorphic forms, and the diffuse reflectance IR spectra of the two forms indicated that the two structures differed in the conformation of one sidechain. The solid state 13C NMR spectra obtained on both forms were found to confirm this hypothesis [19]. As may be seen in Fig. 3, the significant spectral differences were all associated with nuclei contained within the acetal sidechain. 

Fig. 3 Solid state 13C NMR spectra obtained on the A-phase and B-phase polymorphs of fosinopril sodium, illustrating the differences observed in the CH aliphatic and CC aliphatic regions of the spectrum. (Data adapted from Ref. 19.)...

Photomicrographs of the two polymorphs of fosinopril sodium are shown in Fig. 4. The A-phase has been found to be the most stable, and it is normally... 

Analogous to the DuP 747 study, complete crystallographic information was not possible on the fosinopril sodium polymorphic system [25], Two known polymorphs (A and B) were studied via a multidisciplinary approach (XRD, IR, NMR, and thermal analysis). Complementary spectral data from IR and solid state 13C NMR revealed that the environment of the acetal sidechain of fosinopril sodium differed in the two forms. In addition, possible cis-trans isomerization about the CgN peptide bond may exist. These conformational differences are postulated as the origin of the observed polymorphism in fosinopril sodium in the absence of the crystallographic data for form B (single crystals not available). 

Fig. 3 Solid state 31P NMR spectra of fosinopril sodium acquired under single pulse, high-power proton decoupling and various conditions of magic-angle spinning (A) static, (B) 2.5 kHz, (C) 4.0 kHz, (D) 5.0 kHz, and (E) 6.0 kHz. The isotropic chemical shift is designated by an asterisk. (From Ref. 15.)...

Fig. 9 Examples of simplifying solid state NMR spectra by the TOSS and delayed decoupling pulse sequences. Shown is a comparison of the 31P CP/MAS NMR spectrum of fosinopril sodium utilizing the standard pulse sequence (A) and the TOSS routine (B). Also shown is the full 13C CP/MAS NMR spectrum of fosinopril sodium (C) and the nonprotonated carbon spectrum (D) obtained from the delayed decoupling pulse sequence utilizing a 80 /us delay time. Signals due to the methyl carbon resonances (0-30 ppm) are not completely eliminated due to the rapid methyl group rotation, which reduces the carbon-proton dipolar couplings.

Fig. 13 Determination of 31P Tx values for fosinopril sodium using the inversion-recovery method. The spectra represent approximately a 50/50% w/w mixture of polymorphic forms A (8 = 52 ppm) and B (8 = 55 ppm). Spinning sidebands are represented by asterisks. 

Fosinopril sodium, molecular formula and structure, 5 150t... 

Lozano, R., Warren, F. V., Perlman, S., and Joseph, J. M. (1995). Quantitative analysis of fosinopril sodium by capillary zone electrophoresis and liquid chromatography. /. Pharm. Biomed. Anal. 13, 139-148. 

USAN Fosinopril sodium Trade name Monopril ... 

Angiotensin converting ENZYME (ACE) inhibitors captopril cilazapril enalapril maleate fosinopril sodium lisinopril... 

Desmet W, Vrolix M, De Scheerder I, Van Lierde J, Willems JL, Piessens J. Angiotensin-converting enzyme inhibition with fosinopril sodium in the prevention of restenosis after coronary angioplasty. Circulation 1994 89( I ) 385—392. 

Common Name Fosenopril sodium Fosfenopril sodium Fosinopril sodium Chemical Abstracts Registry No. 88889-14-9 98048-97-6 (Base)... 

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