Quantitation of memantine hydrochloride bulk drug and its tablet formulation using proton nuclear magnetic resonance spectrometry

Abstract

The use of quantitative nuclear magnetic resonance spectrometry for the determination of non-UV active memantine hydrochloride with relative simplicity and precision has been demonstrated in this study. The method was developed on a 500 MHz NMR instrument and was applied to determination of the drug in a tablet formulation. The analysis was performed by taking caffeine as an internal standard and D2 O as the NMR solvent. The signal of methyl protons of memantine hydrochloride appeared at 0.75 ppm (singlet) relative to the signal of caffeine (internal standard) at 3.13 ppm (singlet). The method was found to be linear (r(2) = 0.9989) in the drug concentration range of 0.025 to 0.80 mg/ml. The maximum relative standard deviation for accuracy and precision was <2. The limits of detection and quantification were 0.04 and 0.11 mg/ml, respectively. The robustness of the method was revealed by changing nine different parameters. The deviation for each parameter was also within the acceptable limits. The study highlighted possibility of direct determination of memantine hydrochloride in pure form and in its marketed tablet formulation by the use of quantitative NMR, without the need of derivatization, as is the requirement in HPLC studies. Copyright © 2016 John Wiley & Sons, Ltd.

Isolation and identification of the antibacterial compounds in Coptis chinensis for the preservation of wood

“…Substance A was described as yellow needle-like crystals, with the following results: 1 H NMR (500.13 MHz, MeOD) peak was attributed to δ ppm: 9.77 (1H, s, 14-H), 8.71 (1H, s, 11-H ), 8.12 (1H, d, J = 9.5 Hz, 15-H), 8.00 (1H, d, J = 9.0 Hz, 16-H), 7.66 (1H, s, 3-H), 6.96 (1H, s, 6-H), 6.11 (2H, s, 20-OCH2O-), 4.92 (2H, t, J = 6.5Hz, 9-H), 4.20 (3H, s, 22-OCH3-), 4.11(3H, s, 23-OCH3-), 3.25 (2H, t , J = 6.0Hz, 10-H) (Bayar et al 2019); 13 C NMR (125.77 MHz, MeOD) peak was attributed to δ ppm: 152.2, 152.1, 150.0, 146.5, 145.8, 139.8, 135.2, 131.9, 128.1, 124.6, 123.4, 121.9, 121.6, 109.4, 106.6, 103.7, 62.6, 57.7, 57.2, and 28.2. The data from the 1 H NMR and 13 C NMR were consistent with the data reported by Sahu et al (2016). The purity was 91%, as determined via high performance liquid chromatography.…”

The Application of Quantitative 1H-NMR for the Determination of Orlistat in Tablets

“…As has been reported in the literature, the fundamental principle of qNMR is that the NMR signals intensity ( I ) has a direct ratio relation with the number of nuclei ( n ) [ 8 , 9 ], as the following Equation (5) describes: …”

“…First used to determine compound purity and drug content in 1963 [ 1 , 2 ], NMR has since gradually developed into a precise quantitative analysis method. Though it has a lower sensitivity relative to HPLC and mass spectrometry (MS) [ 3 ], the quantitative NMR (qNMR) method possesses distinctive advantages: (1) it can be conducted without analyte reference materials; (2) it can provide structural information and does not destroy the samples; (3) it can undertake multicomponent analysis in a mixture without pre-isolation; and (4) it requires a comparatively short time [ 4 , 5 , 6 , 7 , 8 , 9 ]. Nowadays, qNMR is mainly applied to identify and quantify drugs, biological metabolites, and natural products [ 10 , 11 , 12 , 13 , 14 , 15 , 16 ].…”

Magnetic nanoemulsions as candidates for Alzheimer’s disease dual imaging theranostics

“…The characteristic peaks of Amide I (1700-1550 cm -1 ), Amide II (1550-1450 cm -1 ) and Amide IΙΙ (1400-1200 cm -1 ) were all present in the FTIR spectrum (Figure 3A). [50] Both Memantine (2.2-0.8 ppm) and fluorescein (8-6.5 ppm) protons appeared in 1 H-NMR spectrum [51,52] along with a peak for the amide proton at 8.1 ppm (Figure 3B). In detail, observed peaks are matched to a (0.8 ppm, 6H, Mem), b (1.2 ppm, 2H, Mem), c (1.35 ppm, 4H, Mem), d (1.7 ppm, 4H, Mem), e (1.9 ppm, 2H, Mem), f (2.2 ppm, 1H, Mem), a΄ (6.5 ppm, 4H, Flu), b΄ (8 ppm, 1H, Flu), c΄ (7.8 ppm, 1H, Flu), d΄ (7.7 ppm, 1H, Flu), e΄ (7.25 ppm, 1H, Flu) and f΄ (6.6 ppm, 2H, Flu) protons of the inset of Figure 3B.…”