Analysis of Harmful Substances in Dietary Supplements – Extended AppNote

Dietary Supplements have had, in notable cases, ingredients added to them that have been implicated in serious health issues and even death. Two such pernicious compounds are Aegeline and 1,3-Dimethylamylamine. These two can be readily separated from the dietary supplement matrix using the Cogent Bidentate C18 2.o™   and Cogent Diamond Hydride™ Columns by LCMS […]

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Bisphenol A, BPA Analyzed with HPLC – AppNote

Toxic Substance Found in Consumer Products Analyzed with HPLC Bisphenol A (BPA) is a challenging compound for analysis with HPLC. Monitoring of this environmental and health toxicant is a necessary process for surveillance as well as risk assessment. As shown in the 5 Chromatograms overlaid below, this Method produces Peak Shapes that are Symmetrical and […]

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Chlorpheniramine Maleate Organic Impurities Analyzed with HPLC – AppNote

Separation demonstrated in real commercial formulation extracts Use of the Cogent Bidentate C8™ Column allows for high resolution baseline separation of six specified impurities of Chlorpheniramine Maleate (Fig. A). Fig. B shows how the method can be applied to a real-world formulation, spiked with the N-oxide impurity to demonstrate resolution from the API peak. Currently, […]

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Clindamycin Antibiotic Tablet Analyzed with HPLC – AppNote

Separation of API from Excipients  The Stability and Robustness of this Method makes it an excellent choice for QC of this semi-synthetic antibiotic which is structurally related to Lincomycin. The Chromatogram shown below of Clindamycin is from a complex Pharmaceutical Formulation but note the excellent Peak Shape for it and the Separation from the Excipients. […]

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Dehydroepiandrosterone (DHEA) Capsule Separation with HPLC – AppNote

Excellent separation from matrix excipients Pharmaceutical formulations may contain a number of excipients that can potentially interfere with a chromatographic analysis. However, using the Cogent Bidentate C8 Column, the DHEA peak is well-resolved from the others, the latter of which all elute as a large peak in the solvent front portion of the run. The […]

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Diazepam Tablet Analyzed with HPLC – AppNote

Excellent Peak Shape and Precision for a Benzodiazepine Compound Valium® This Isocratic Method shows how using 0.1% Trifluoroacetic Acid (TFA) in the Mobile Phase can produce a Peak with excellent Efficiency and Symmetry. In the USP Assay Method, System Suitability requires that a tailing factor of not more than 2.0 be obtained for the API, […]

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Furazolidone Analyzed with HPLC – AppNote

Improved Specificity Compared to USP Assay Method The USP Assay Method for Furazolidone is performed by UV Spectrophotometry. This HPLC Method provides more Robustness and Specificity for the analysis. Separation of Furazolidone from the structurally similar compound Nitrofurantoin is shown in the figure. Nitrofurantoin can be used as an internal standard to obtain more robust […]

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Guanfacine HCL and Degradants Analyzed with HPLC – AppNote

USP Method with an SDS Resistant Column The US Pharmacopeia (USP) lists several known degradation products for Guanfacine. The Figure below shows a Separation of a degraded Guanfacine Drug Substance. This Method produces very Efficient results but what is important to note is that the Column used is extremely stable under the very aggressive Mobile […]

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Hormone Replacement HPLC Methods – Extended AppNote

Ethinylestradiol, Norethisterone Acetate, Estriol, Estradiol, Progesterone, Separation in Hormone Replacement Formulations. Often, these formulations have multiple active ingredients present, therefore HPLC is an appropriate technique in obtaining the necessary specificity for a Quantitative Assay. This Method can retain the Hormones by conventional Reversed Phase HPLC and can also differentiate among the compounds by shape. The […]

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Hormone Replacement Tablet Analyzed with HPLC – AppNote

Isocratic Separation of Ethinylestradiol and Norethisterone Acetate In this simple HPLC Method, two hormones from a tablet extract are separated. Both analytes are adequately retained while keeping the run time to 10 minutes. The USP Monograph Method for Assay of the two compounds is lengthy and complex, while this Method is rapid and easy to […]

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Hydrophobic Compounds Analyzed With HPLC – AppNote

Shorter Analysis Time For separations requiring a less hydrophobic Stationary Phase, Cogent C8 can be used successfully as demonstrated in the Chromatograms. The Retention on the C8 Column is lower when compared with a C18 Column under the same Mobile Phase conditions, but since the Efficiency is excellent the separation goals can be achieved in […]

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Mometasone Furoate in Topical Cream Analyzed with HPLC – AppNote

Separation of Prodrug from Acid Hydrolysis Products This Method shows the Separation of an ester Prodrug, Mometasone Furoate, from another compound formed during acid hydrolysis. This Peak is quite possibly the active form, Mometasone. The two Chromatograms show the non-degraded extract (Figure A) and an acid hydrolysis extract (Figure B). Hydrolysis of the ester group […]

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Prednisone Analyzed with HPLC – AppNote

Isocratic Method for Prednisone Tablets  This Method uses the Mobile Phase specified in the USP Method for Assay of Prednisone tablets. The resolution between the API and the Acetanilide Internal Standard meets the system suitability. Resolution was found to be superior compared to standard C18 HPLC Columns. In addition, this Method also produces excellent precision […]

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Sulfisoxazole Acetyl Analyzed with HPLC – AppNote

Separation of two Common Preservatives from the API in a Pharmaceutical Suspension Orally administered suspensions with Sulfisoxazole Acetyl often contain the preservatives Methyl and Propyl Paraben. As such, it is important to separate these compounds from the API in an HPLC Assay Method to properly analyze the suspension. With this Method, excellent Separation is obtained […]

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Tramadol Tablet Analyzed with HPLC – AppNote

An API with a Tertiary Amine – Easy & Efficient Method for Analysis This Method for the Analysis of Tramadol Tablets, produces an Efficient Peak Shape for the API. The Peak is highly Symmetrical, which is often difficult to obtain for compounds with a tertiary amine. Tramadol has chiral centers but this Method does not […]

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