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

Abstract

A quantitative nuclear magnetic resonance (qNMR) method to measure the content of Orlistat in tablets was studied and found to be efficient, accurate, reliable, and simple. In this paper, phloroglucinolanhydrous and dimethylsulfoxide-d6 (DMSO-d6) served as the internal standard and solvent, respectively. The qNMR methodology, including the linearity, range, the limit of detection (LOD) and quantification (LOQ), stability, precision, and accuracy, was validated seriatim, and the results were very favorable. The content determination results of three batches of Orlistat in tablets were almost identical upon comparing the qNMR method and the high-performance liquid chromatography (HPLC) method. The recommended method authentically compensated the deficiencies of the current HPLC method for determining Orlistat content, and proved to be a method complementary to traditional analysis for the purity measurement of Orlistat in some pharmaceutical preparations.

Benchtop NMR for Online Reaction Monitoring of the Biocatalytic Synthesis of Aromatic Amino Alcohols

“…To ensure correct quantification of NMR signals, the longitudinal relaxation time (T 1 ) is one of the most important values . Relaxation describes the process of dynamic return of the spins to the initial equilibrium state after a pulse experiment and T 1 is the time that this process takes .…”

“…For correct quantification, the time between two pulse experiments (spectrum scans) should be at least 5‐ to 7‐times the value of the relaxation time to ensure that all spins (99.9 % in the case of 7×T 1 ) have returned to the initial state before starting the next pulse sequence. If the time between the scans is less than 5‐ to 7‐times T 1 , the signal intensity will successively decrease and is then no longer directly correlated with the concentration of the component.…”

“…The limit of quantification (LOQ) was determined using a concentration series of substrate (3OH‐BA), intermediate (3OH‐PAC) and final product (3OH‐AHP) in the range of 2.5 mM–25 mM, and determining the signal‐to‐noise ratio (SNR) depending on the number of scans used for spectra acquisition. The LOQ was defined as the concentration value where the SNR was ten, which is an appropriate value according to literature, and was calculated from linear regression. It should be noted that the SNR is additionally dependent on the shim status of the spectrometer.…”

Assessment of the triacylglycerol fraction of olive oil by 1D-NMR spectroscopy: exploring the usefulness of DEPT tool on the peak assignments of 13C NMR spectra

“…Indeed, NMR seems to be a very promising analytical technique for the analysis of olive oils. Some remarkable aspects could be ascribed such as, it not requires the use of reference compounds, does not destroy the samples being possible to recover them, and it analyses simultaneously various components without pre-isolation of the target compounds [13]. Moreover, the process is more sustainable, particularly from an economic point of view.…”

“…Moreover, compounds that play a crucial role on the stability of olive oils can also assessed which is particularly relevant for some OO's topics, such as storage and shell-life of olive oils [5,18,[22][23][24][25][26]. However, 1 H NMR is not useful to assign the positional distribution of the fatty acids in the glycerol backbone [2] while 13 C NMR spectroscopy provides information at this level since the main resonances observed in the 13 C NMR spectrum belong to triacylglycerides (Fig. 1).…”