Publications by authors named "John J Salisbury"

L-pidolic acid is being used as a coformer for ertugliflozin, a sodium-glucose cotransport 2 inhibitor. A sensitive and rapid two-step achiral derivatization combined with gas chromatography with flame ionization detection or gas chromatography with mass spectroscopic detection was developed and validated for the enantiomeric purity determination of L-pidolic acid in the drug substance and drug product, respectively. The method was used to analyze ertugliflozin drug substance forced degradation samples and showed no racemization of pidolic acid in any of the solid or solution stress samples.

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A sensitive and rapid analytical method has been validated for the enantiomeric purity determination of l-pidolic acid, a biological lactam and metabolite of glutamic acid commonly found in urine, skin, bones, brain and is available commercially as a food supplement. An efficient, two-step achiral derivatization was implemented which consisted of an alkylation step (using HCl-IPA) followed by an acylation step (using TFAA) of the carboxy and amide functional groups. This allowed detection with high sensitivity using gas chromatography with flame ionization detection.

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This paper describes the development and validation of a high temperature gas chromatography flame ionization detection (HTGC-FID) method for the purity evaluation of arene substituted regioisomers in a key starting material of a pharmaceutical candidate in Phase 3 studies. The chromatographic conditions of the method employ a (5%-phenyl)-methylpolysiloxane packed column (30m×0.25mm) at a constant flow of 1.

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Quantitative NMR spectrometry (qNMR) is an attractive, viable alternative to traditional chromatographic techniques. It is a fast, easy, accurate, and nondestructive technique which allows an analyst to gain quantitative information about a component mixture without the necessity of authentic reference materials, as is the case with most other analytical techniques. This is ideal for the synthesis of active pharmaceutical ingredients (API) that are in the early stages of development where authentic standards of the analytes may not be available.

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The benefits of sub-2 micron particle size columns have been widely researched and published. The use of these columns on ultrahigh-pressure liquid chromatography (UHPLC) instrumentation may lead to increased efficiencies and higher throughput. However, these instruments may not be readily available to the pharmaceutical chemist.

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Pharmaceutical separations can be divided into three categories: high throughput, high productivity, and high resolution. These categories contain specific pharmaceutical applications, each of which has distinct separation goals. Traditionally, these goals have been achieved utilizing conventional HPLC with typical column dimensions and particle sizes.

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