Kinetics of the Esterification of Active Pharmaceutical Ingredients Containing Carboxylic Acid Functionality in Polyethylene Glycol: Formulation Implications

2014 ◽  
Vol 103 (8) ◽  
pp. 2424-2433 ◽  
Author(s):  
Anne Marie V. Schou-Pedersen ◽  
Steen Honoré Hansen ◽  
Birthe Moesgaard ◽  
Jesper Østergaard
Keyword(s):  
Polyethylene Glycol ◽  
Carboxylic Acid ◽  
Active Pharmaceutical Ingredients ◽  
Pharmaceutical Ingredients ◽  
Kinetics Of

Reversed-Phase High Performance Liquid Chromatographic Analysis of Three First Line Anti-Tuberculosis Drugs

2019 ◽  
Vol 69 (12) ◽  
pp. 3590-3592
Author(s):  
Nela Bibire ◽  
Romeo Iulian Olariu ◽  
Luminita Agoroaei ◽  
Madalina Vieriu ◽  
Alina Diana Panainte ◽  
...  
Keyword(s):  
High Performance ◽  
Biological Fluids ◽  
Gradient Elution ◽  
High Performance Liquid Chromatographic ◽  
Reversed Phase ◽  
Assay Method ◽  
Active Pharmaceutical Ingredients ◽  
First Line ◽  
Pharmaceutical Ingredients ◽  
Liquid Chromatographic

Active pharmaceutical ingredients such as isoniazid, pyrazinamide and rifampicin are among the most important first-line anti-tuberculosis drugs. A simple, rapid and sensitive reversed phase-high performance liquid chromatographic assay method for the simultaneous determination of isoniazid, pyrazinamide and rifampicin has been developed. Separation of the interest compounds was achieved in a 10 min chromatographic run in gradient elution mode on a Zorbax SB-C18 stainless steel column (150 � 4 mm, 5 mm) using a guard column containing the same stationary phase. The gradient elution was carried out with a mobile phase of 10% CH3CN aqueous solution for channel A and 50% CH3CN in pH = 6.8 phosphate buffer (20 mM), to which 1.5 mL triethylamine were added for channel B. Quantification of the analyzed substances was carried out spectrophotometrically at 269 nm. Detection limits of 0.48 mg/L for isoniazid, 0.52 mg/L for pyrazinamide and 0.48 mg/L for rifampicin were established for the developed assay method. The present work showed that the proposed analysis method was advantageous for simple and rapid analysis of the active pharmaceutical ingredients in pharmaceuticals and biological fluids.

Kinetics of Substitution of 4-Methoxyphenylazo Groups of 2,6-Dioxo-5(3)-(4-methoxyphenylazo)-3(5)-(4-methoxyphenylhydrazono)-1,2,3,6-tetrahydropyridine-4-carboxylic Acid by Reaction with 4-Nitrobenzenediazonium Cation

1994 ◽  
Vol 59 (7) ◽  
pp. 1665-1672 ◽  
Author(s):  
Jaroslava Horáčková ◽  
Vojeslav Štěrba
Keyword(s):  
Carboxylic Acid ◽  
Rate Constant ◽  
Kinetics Of

Kinetics have been studied of gradual replacement of 4-methoxyphenylazo groups in 2,6-dioxo-5(3)-(4-methoxyphenylazo)-3(5)-(4-methoxyphenylhydrazono)-1,2,3,6-tetrahydropyridine-4-carboxylic acid (IIIa) by 4-nitrophenylazo groups using the reaction with 4-nitrobenzenediazonium cation (IIc) in acetate and phosphate buffers. The rate constant of replacement of the second methoxyphenylazo group is lower by a factor of ca 60. From the experimentally found pKa values of the corresponding azohydrazone compounds with methoxy, chloro, or nitro substituent at 4-position (IIIa - IIIf) it has been concluded that the 5(3)-(4-methoxyphenylazo)-3(5)-(4-nitrophenylhydrazono) derivative is formed in the first step.

scholarly journals Numaswitch: an efficient high-titer expression platform to produce peptides and small proteins

AMB Express ◽  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Bach-Ngan Nguyen ◽  
Florian Tieves ◽  
Thomas Rohr ◽  
Hilke Wobst ◽  
Felix S. Schöpf ◽  
...  
Keyword(s):  
Fermentation Broth ◽  
High Titer ◽  
New Technology ◽  
Active Pharmaceutical Ingredients ◽  
Pharmaceutical Ingredients ◽  
Expression Platform ◽  
Small Proteins ◽  
Production Platform ◽  
Β Amyloid ◽  
Cost Efficient

AbstractThe production of peptides as active pharmaceutical ingredients (APIs) by recombinant technologies is of emerging interest. A reliable production platform, however, is still missing due the inherent characteristics of peptides such as proteolytic sensitivity, aggregation and cytotoxicity. We have developed a new technology named Numaswitch solving present limitations. Numaswitch was successfully employed for the production of diverse peptides and small proteins varying in length, physicochemical and functional characteristics, including Teriparatide, Linaclotide, human β-amyloid and Serum amyloid A3. Additionally, the potential of Numaswitch for a cost-efficient commercial production is demonstrated yielding > 2 g Teriparatide per liter fermentation broth in a quality meeting API standard.

scholarly journals Diagnosis of Agglomeration and Crystallinity of Active Pharmaceutical Ingredients in Over the Counter Headache Medication by Electrospray Laser Desorption Ionization Mass Spectrometry Imaging

Molecules ◽  
2021 ◽  
Vol 26 (3) ◽  
pp. 610
Author(s):  
Mariann Inga Van Meter ◽  
Salah M. Khan ◽  
Brynne V. Taulbee-Cotton ◽  
Nathan H. Dimmitt ◽  
Nathan D. Hubbard ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Mass Spectrometry Imaging ◽  
Laser Desorption ◽  
Ionization Mass Spectrometry ◽  
Ionization Mass ◽  
Active Pharmaceutical Ingredients ◽  
Laser Desorption Ionization ◽  
Over The Counter ◽  
Pharmaceutical Ingredients ◽  
Desorption Ionization

Agglomeration of active pharmaceutical ingredients (API) in tablets can lead to decreased bioavailability in some enabling formulations. In a previous study, we determined that crystalline APIs can be detected as agglomeration in tablets formulated with amorphous acetaminophen tablets. Multiple method advancements are presented to better resolve agglomeration caused by crystallinity in standard tablets. In this study, we also evaluate three “budget” over-the-counter headache medications (subsequently labeled as brands A, B, and C) for agglomeration of the three APIs in the formulation: Acetaminophen, aspirin, and caffeine. Electrospray laser desorption ionization mass spectrometry imaging (ELDI-MSI) was used to diagnose agglomeration in the tablets by creating molecular images and observing the spatial distributions of the APIs. Brand A had virtually no agglomeration or clustering of the active ingredients. Brand B had extensive clustering of aspirin and caffeine, but acetaminophen was observed in near equal abundance across the tablet. Brand C also had extensive clustering of aspirin and caffeine, and minor clustering of acetaminophen. These results show that agglomeration with active ingredients in over-the-counter tablets can be simultaneously detected using ELDI-MS imaging.

Sign in / Sign up

Export Citation Format

Share Document