Determination and Validation of Piracetam in Pharmaceuticals Using Quantitative Nuclear Magnetic Resonance Spectroscopy

El-Adl, Sobhy M.; El-Sadek, Mohamed; Hasan, Marwa H.

doi:10.1080/22297928.2017.1320227

Cited by 3 publications

(1 citation statement)

References 25 publications

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“…The quantity of cis-DHQ was lower (9.5 %), and trans/cis-isomers ratio was 8 : 1. Several studies noted that validation parameters values for the quantitative analysis performed via NMR spectroscopy and HPLC are comparable [33][34][35][36]. Taking into account the fact that diastereomers may be characterized by different values of molar extinction coefficients at the same wavelengths [37][38][39], it can be considered that without a reference sample of cis-DHQ, NMR spectroscopy is a more specific and preferable method for quantitative analysis of DHQ diastereomers.…”

Section: Discussioinmentioning

confidence: 99%

Analysis of <i>cis</i>-isomer-enriched dihydroquercetin sample by 1D and 2D NMR spectroscopy

Terekhov,

Taldaev,

Bocharov

et al. 2024

Razrabotka i registraciâ lekarstvennyh sredstv

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Introduction. The structure of dihydroquercetin (DHQ) is characterized by two chiral centers at positions 2 and 3 of the benzopyran cycle, resulting in possible diastereomers: trans- and cis-isomers. Therefore, the development of methods for qualitative and quantitative control of DHQ diastereomers in analyzed samples is essential for patient safety management. Nuclear magnetic resonance (NMR) spectroscopy is one of the physicochemical methods that can be used for this purpose.Aim. The study objective was to accumulate the analytical and structural characteristics of cis-DHQ by NMR spectroscopy of the spheroidal form of this flavonoid (DHQs).Materials and Methods. 1D 1H, 1H,1H-COSY, 1H,1H-NOESY, and 1H,13C-HSQC NMR spectra were acquired at 298 K on an 800 MHz NMR spectrometer equipped with a TXI triple resonance probe. The number of scans was 32. The mixing time in the NOESY experiment was 400 ms. The 1H and 13C were analyzed using CcpNmr software. The dihedral angles were calculated by applying the Karplus equation.Results and discussion. In trans-DHQ, the chemical shift values for H2 and H3 are 4.93 ppm and 4.52 ppm, respectively, and in cis-DHQ they are 5.31 ppm and 4.20 ppm, respectively. The spin-spin coupling constants between H2 and H3 of trans- and cis-DHQ are 12.00 Hz and 2.40 Hz, respectively. Thus, the dihedral angles for the trans- and cis-isomers are 154° and 64°, respectively. We found that DHQs contains 12.5 % of the cis-isomer.Conclusion. Our experiments confirmed that NMR spectroscopy can discriminate between trans- and cis-DHQ based on the chemical shift values for the cross-peaks of H2 and H3. The second major finding was that this method can be considered as a more selective quantitative analysis than HPLC with UV detection without reference. One of the most important results of this study for drug development is the updated information on the structural parameters of DHQ diastereomers in the liquid phase.

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Section: Discussioinmentioning

confidence: 99%

Analysis of <i>cis</i>-isomer-enriched dihydroquercetin sample by 1D and 2D NMR spectroscopy

Terekhov,

Taldaev,

Bocharov

et al. 2024

Razrabotka i registraciâ lekarstvennyh sredstv

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Quantitative 1HNMR Spectroscopy: Analysis of Zinc Gluconate in Utozinc® Tablets, a Mixture of Zinc Gluconate and Vitamin C

Hassan

2022

Journal of AOAC INTERNATIONAL

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Background Zinc is an essential metal for humans and plays key roles in several biological events such as immunity, allergy, growth, and inflammation. The deficiency in zinc causes an increased infection rate with pathogens. Organo-zincates such as zinc gluconate are known for better absorption compared with their inorganic zinc salts. Its role in enhancing the immune system has driven a huge demand for organo-zinc supplements and in the treatment protocol of coronavirus disease, the causative agent of the COVID-19 pandemic. Objective Herein, we report on a quantitative analysis of zinc gluconate in the authentic form in presence of vitamin C and the method was applied to their dosage form (UtozincR tablets). The method is simple, accurate, and validated according to ICH guidelines. Methods Quantification of zinc gluconate formulated with vitamin C (UtozincR tablets) using Q-1HNMR. Maleic acid and deuterium oxide were used as internal standards and solvents, respectively. Results The linearity range, the limit of detection and quantification, stability, precision, and accuracy, were validated. The validation of the method within five concentration levels (from 10 to 50 mg/0.5 mL D2O) afforded a limit of detection of 4.58 mg/mL, a quantification limit of 15.27 mg/mL, and excellent linearity. Conclusion The method proposed in the present study is simple, fast, non-destructive, and accurate. Zinc gluconate quantification values obtained by the Q-1HNMR method were found to show an acceptable correlation with those obtained by the thin-layer chromatographic technique. Highlights The method was successfully applied on UtozincR tablets, and the results were compared with the reported reference pharmacopeial method. The salt exchange between maleic acid (IS) and zinc gluconate was tested by noticing the change in the chemical shift of IS and zinc gluconate.

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Rapid Quantitation of Non-chromophoric Vigabatrin and Gabapentin by a Validated qNMR Method in Bulk Drug and Marketed Formulations

Bedage,

Sahu,

Singh

2024

CPA

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Background:: Vigabatrin and gabapentin, commonly used antiepileptic drugs in clinics, lack a UV active chromophore and, therefore, require cumbersome derivatization methods for analysis by HPLC using fluorescence detection. This study demonstrated the use of NMR for their quantitative determination in pure form and their pharmaceutical formulations. Objective:: To develop a validated qNMR method for non-chromophoric drugs Vigabatrin and Gabapentin. Methods:: The signal of methine proton of vigabatrin at 3.67 ppm relative to the signal of maleic acid at 6.17 ppm and the methylene signal of gabapentin at 2.88 ppm relative to the signal of caffeine at 7.75 ppm was used for qNMR. The developed method was validated with respect to linearity, limits of detection and quantitation, accuracy, precision, specificity and solution state stability. Results:: Linearity range and r2 were found to be from 2.66 to 42.11 mg/mL and 0.9999. The limit of detection and quantification were 0.0129 mg/mL and 0.0391 mg/mL, respectively, for vigabatrin. This method was found to be linear (0.9998) and specific within the gabapentin concentration range from 1.07 to 34.24 mg/mL of D2O. The limits of detection and quantification were 0.0248 mg/mL and 0.0751 mg/mL, respectively. Conclusion:: Both methods were highly precise, with a calculated RSD of 0.60 % and 0.76 %, respectively. The robustness of the methods was revealed by changing pre and post-processing NMR parameters. The developed methods provide a simple and straight approach for the absolute determination of gabapentin and vigabatrin in bulk drugs and their marketed formulations without any pre-procedures.

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Determination and Validation of Piracetam in Pharmaceuticals Using Quantitative Nuclear Magnetic Resonance Spectroscopy

Cited by 3 publications

References 25 publications

Analysis of <i>cis</i>-isomer-enriched dihydroquercetin sample by 1D and 2D NMR spectroscopy

Analysis of <i>cis</i>-isomer-enriched dihydroquercetin sample by 1D and 2D NMR spectroscopy

Quantitative 1HNMR Spectroscopy: Analysis of Zinc Gluconate in Utozinc® Tablets, a Mixture of Zinc Gluconate and Vitamin C

Rapid Quantitation of Non-chromophoric Vigabatrin and Gabapentin by a Validated qNMR Method in Bulk Drug and Marketed Formulations

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