Comparison of liquid chromatographic method to AOAC microbiological method for determination of L-tryptophan in tablets and capsules.

J AOAC Int

U.S. Food and Drug Administration, Division of Nutrition, Washington, DC 20204.

Published: May 1993

A reversed-phase liquid chromatographic (LC) method coupled with precolumn derivatization of L-tryptophan with phenylisothiocyanate was compared to the AOAC microbiological method for determining L-tryptophan in tablets and capsules. For the microbiological method, the concentrations of L-tryptophan were 4-8% lower in autoclaved test samples (hot method) than in test samples that were not autoclaved (cold method). When L-tryptophan values obtained by the LC method were compared to those obtained by the cold microbiological method, no significant differences were observed (P > 0.05). The mean relative standard deviations were 2.9% for the LC method and 1.6% for the cold microbiological method. The mean recoveries of standard L-tryptophan added before analysis were 99% for the LC method and 101% for the cold microbiological method. These results demonstrate that both methods are reliable for determining free L-tryptophan contained in tablets and capsules. However, the LC method has the advantages of using a smaller test portion and having a shorter analysis time.

Download full-text PDF

Source

Publication Analysis

Top Keywords

microbiological method
24
method
14
tablets capsules
12
cold microbiological
12
liquid chromatographic
8
chromatographic method
8
aoac microbiological
8
l-tryptophan tablets
8
test samples
8
l-tryptophan
7

Similar Publications

Introduction: Recurrent uveitis (RU), an autoimmune disease, is a leading cause of ocular detriment in humans and horses. Equine and human RU share many similarities including spontaneous disease and aberrant cytokine signaling. Reduced levels of SOCS1, a critical regulator of cytokine signaling, is associated with several autoimmune diseases.

View Article and Find Full Text PDF

Highly sensitized (HS) patients in need of kidney transplantation (KTx) typically spend a longer time waiting for compatible kidneys, are unlikely to receive an organ offer, and are at increased risk of antibody-mediated rejection (AMR). Desensitization using imlifidase, which is more rapid and removes total body immunoglobulin G (IgG) to a greater extent than other methods, enables transplantation to occur between HLA-incompatible (HLAi) donor-recipient pairs and allows patients to have greater access to KTx. However, when the project was launched there was limited data and clinical experience with desensitization in general and with imlifidase specifically.

View Article and Find Full Text PDF

Objective: To determine the prevalence of antimicrobial resistance (AMR) in isolated from urine cultures of patients with uncomplicated cystitis in Pakistan. Another objective was to analyze and compare the resistance rates of to specific antibiotics, conducting a year-by-year evaluation of these rates to identify trends and changes over the past seven years.

Methods: Retrospective analysis of susceptibility data of isolated from midstream urine culture samples of patients presenting in outpatient department with uncomplicated cystitis, from January 2016 to December 2022 in the section of Microbiology, Liaquat University of Medical and Health Sciences was done.

View Article and Find Full Text PDF

Background & Objective: Chronic suppurative otitis media is a fatal condition owing to its propensity for intracranial extension. The inadvertent use of antibiotics has led to resistance among causative organisms. The objectives of this study were to determine causative bacteria, their antibiotic resistance and susceptibility patterns, and their response to antibiotics after a one-month follow-up.

View Article and Find Full Text PDF

Introduction: Surveillance of antibiotic use is crucial for identifying targets for antibiotic stewardship programs (ASPs), particularly in pediatric populations within countries like Pakistan, where antimicrobial resistance (AMR) is escalating. This point prevalence survey (PPS) seeks to assess the patterns of antibiotic use in pediatric patients across Punjab, Pakistan, employing the WHO AWaRe classification to pinpoint targets for intervention and encourage rational antibiotic usage.

Methods: A PPS was conducted across 23 pediatric wards of 14 hospitals in the Punjab Province of Pakistan using the standardized Global-PPS methodology developed by the University of Antwerp.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!