Assessment of Quality of Azithromycin, a Macrolide Antibiotic by NMR Spectroscopy

A total of forty-five pharmaceutical tablets containing 500 mg azithromycin from 9 (nine) different companies were collected from local pharmacies and evaluated the quality of the antibiotics with standard azithromycin by physical, chromatographic (HPLC), Fourier Transform Infrared (FT-IR), and 1H & 13C Nuclear Magnetic Resonance (NMR) spectroscopic studies. Weight variation of all tested tablets were within 0.1-1.8% which is in the allowed variation of 5%. Two prominent absorption bands were observed at 1723 and 1187 cm−1 in the FT-IR spectrum of all samples and standard for the presence of >C=O and -C-O groups, respectively due to the macrocyclic lactone ring. HPLC coupled with PDA detector (at 210 and 215 nm) gave reproducible results at retention time of 10.5 min for standard and samples. The 1H and 13C NMR spectral data of the standard azithromycin and test samples were found to be identical which led to the conclusion that 1H- and 13C-NMR experiments are feasible tools for qualitative determination of azithromycin in tablets. All the described methods determined the quality of analyzed tablets well. Bangladesh Pharmaceutical Journal 24(1): 37-44, 2021

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A Comparison of FT-IR/PA and FT-IR/PBD Spectra of Powders

Applied Spectroscopy ◽

10.1366/0003702864508539 ◽

1986 ◽

Vol 40 (5) ◽

pp. 636-641 ◽

Cited By ~ 5

Author(s):

P. G. Varlashkin ◽

M. J. D. Low ◽

G. A. Parodi ◽

C. Morterra

Keyword(s):

Probe Beam ◽

Beam Deflection ◽

Signal To Noise ◽

Absorption Bands ◽

Ir Radiation ◽

Laser Probe ◽

Ft Ir ◽

Better Than

FT-IR photoacoustic (PA) and also photothermal beam deflection (PBD) spectra were recorded with the same particulate samples (graphite, charcoal, aspirin, and silica) under the same conditions in order to compare the quality of the spectra obtainable with the two techniques. A PA cell fitted with windows for the PBD laser probe beam was used, and PA and PBD spectra of each sample were recorded at 8 cm−1 resolution at each of the four different interferometer scan velocities. Although the overall aspects of FT-IR/PA and FT-IR/PBD spectra are the same, the signal-to-noise ratios of PA spectra are appreciably better than those of PBD spectra because PBD detection is more prone to disturbance by vibration than is PA detection. Absorption bands appear at the same wavenumbers in PA and PBD spectra. However, the relative intensities of bands of PBD spectra depend on the absorptive properties of the powdered solids; with weak absorbers, some bands may not be detected at all. PAS can be used with all powders. PBDS is of little or no use for the examination of weakly absorbing powders unless they scatter IR radiation extensively.

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Spectroscopic (FT-IR, FT-Raman, UV, 1H and 13C NMR) profiling and computational studies on methyl 5-methoxy-1H-indole-2-carboxylate: A potential precursor to biologically active molecules

Journal of Molecular Structure ◽

10.1016/j.molstruc.2016.12.004 ◽

2017 ◽

Vol 1133 ◽

pp. 199-210 ◽

Cited By ~ 15

Author(s):

Maha S. Almutairi ◽

S. Xavier ◽

M. Sathish ◽

Hazem A. Ghabbour ◽

S. Sebastian ◽

...

Keyword(s):

13C Nmr ◽

Biologically Active ◽

Computational Studies ◽

1H And 13C Nmr ◽

Ft Ir ◽

Potential Precursor ◽

Ft Raman

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Synthesis, crystal structure, spectroscopic (FT-IR, 1H and 13C NMR) and nonlinear optical properties of a novel potential HIV-1 protease inhibitor

Chemical Physics Letters ◽

10.1016/j.cplett.2020.137171 ◽

2020 ◽

Vol 742 ◽

pp. 137171

Author(s):

A. Pekparlak ◽

Ö. Tamer ◽

S.D. Kanmazalp ◽

N. Berber ◽

M. Arslan ◽

...

Keyword(s):

Crystal Structure ◽

Optical Properties ◽

Protease Inhibitor ◽

13C Nmr ◽

Nonlinear Optical ◽

Nonlinear Optical Properties ◽

1H And 13C Nmr ◽

Ft Ir ◽

Hiv 1

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Study on Soy-Based Adhesives Enhanced by Phenol Formaldehyde Cross-Linker

Polymers ◽

10.3390/polym11020365 ◽

2019 ◽

Vol 11 (2) ◽

pp. 365 ◽

Cited By ~ 7

Author(s):

Zhigang Wu ◽

Xuedong Xi ◽

Hong Lei ◽

Jiankun Liang ◽

Jingjing Liao ◽

...

Keyword(s):

13C Nmr ◽

Soy Protein ◽

Water Resistance ◽

Phenol Formaldehyde ◽

Ionization Mass ◽

Model Compounds ◽

Esi Ms ◽

13C Nuclear Magnetic Resonance ◽

Ft Ir ◽

Cross Linker

To find the effects of cross-linker phenol-formaldehyde (PF) resin on the performance of soy-based adhesives, the reaction between model compounds hydroxymethyl phenol (HPF) and glutamic acid were studied in this paper. HPF prepared in laboratory conditions showed higher content of hydroxymethyl groups than normal PF resin, which was proved by the results of Electrospray Ionization Mass Spectrometry (ESI-MS) and 13C Nuclear Magnetic Resonance (13C-NMR). The results of ESI-MS, Fourier transform infrared spectroscopy (FT-IR), and 13C-NMR based on resultant products obtained from model compounds showed better water resistance of the soy protein-based adhesive modified by PF-based resin, which indicated the reaction between PF resin and soy protein. However, it seemed that the soy-based adhesive cross-linked by HPF with the maximum content of hydroxymethyl groups did not show the best water resistance.

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