Investigation of tryptophan-related yellowing in parenteral amino acid solution: Development of a stability-indicating method and assessment of degradation products in pharmaceutical formulations

Stability of Protein Pharmaceuticals: Recent Advances

There have been significant advances in the formulation and stabilization of proteins in the liquid state over the past years since our previous review. Our mechanistic understanding of protein-excipient interactions has increased, allowing one to develop formulations in a more rational fashion. The field has moved towards more complex and challenging formulations, such as high concentration formulations to allow for subcutaneous administration and co-formulation. While much of the published work has focused on mAbs, the principles appear to apply to any therapeutic protein, although mAbs clearly have some distinctive features. In this review, we first discuss chemical degradation reactions. This is followed by a section on physical instability issues. Then, more specific topics are addressed: instability induced by interactions with interfaces, predictive methods for physical stability and interplay between chemical and physical instability. The final parts are devoted to discussions how all the above impacts (co-)formulation strategies, in particular for high protein concentration solutions.'

A Review of Sensors and Biosensors Modified with Conducting Polymers and Molecularly Imprinted Polymers Used in Electrochemical Detection of Amino Acids: Phenylalanine, Tyrosine, and Tryptophan

Recently, the studies on developing sensors and biosensors-with an obvious interdisciplinary character-have drawn the attention of many researchers specializing in various fundamental, but also complex domains such as chemistry, biochemistry, physics, biophysics, biology, bio-pharma-medicine, and bioengineering. Along these lines, the present paper is structured into three parts, and is aimed at synthesizing the most relevant studies on the construction and functioning of versatile devices, of electrochemical sensors and biosensors, respectively. The first part presents examples of the most representative scientific research focusing on the role and the importance of the phenylalanine, tyrosine, and tryptophan amino acids, selected depending on their chemical structure and their impact on the central nervous system. The second part is dedicated to presenting and exemplifying conductor polymers and molecularly imprinted polymers used as sensitive materials in achieving electrochemical sensors and biosensors. The last part of the review analyzes the sensors and biosensors developed so far to detect amino acids with the aid of conductor polymers and molecularly imprinted polymers from the point of view of the performances obtained, with emphasis on the detection methods, on the electrochemical reactions that take place upon detection, and on the electroanalytical performances. The present study was carried out with a view to highlighting, for the benefit of specialists in medicine and pharmacy, the possibility of achieving and purchasing efficient devices that might be used in the quality control of medicines, as well as in studying and monitoring diseases associated with these amino acids.

Parenteral nutrition compatibility and stability: A comprehensive review

Several guidance documents support best practices across the stages of the parenteral nutrition (PN)-use process to optimize patient safety. The critical step of PN order verification and review by the pharmacist requires a contextual assessment of the compatibility and stability implications of the ordered PN prescription. This article will provide working definitions, describe PN component characteristics, and present a wide-ranging representation of compatibility and stability concerns that need to be considered prior to preparing a PN admixture. This paper has been approved by the ASPEN Board of Directors. This article is protected by copyright. All rights reserved.

Lichtschutz für Lösungen zur parenteralen Ernährung von Säuglingen und Kindern bis zum Alter von 2 Jahren

Das Bundesinstitut für Arzneimittel und Medizinprodukte (BfArM) empfahl im Rote-Hand-Brief vom 02.09.2019: „Während der Verabreichung an Neugeborene und Kinder unter 2 Jahren sollen entsprechend zugelassene Arzneimittel zur parenteralen Ernährung (PE), die Aminosäuren und/oder Fettemulsionen enthalten, vor Licht geschützt werden (Behältnisse und Infusionsbestecke)“.

Ziel dieser Stellungnahme ist es, evidenzbasierte Empfehlungen zum Lichtschutz für Lösungen zu parenteraler und heimparenteraler Ernährung bei Säuglingen und Kindern bis zum Alter von 2 Jahren zu geben.

Der Bundesverband Deutscher Krankenhausapotheker, die Ernährungskommission der Deutschen Gesellschaft für Kinder- und Jugendmedizin, die Ernährungskommission der Österreichischen Gesellschaft für Kinder und Jugendheilkunde und die Arbeitsgemeinschaft Chronisches Darmversagen der Gesellschaft für Pädiatrische Gastroenterologie und Ernährung empfehlen in Übereinstimmung mit den internationalen Empfehlungen zur pädiatrischen parenteralen Ernährung der Fachgesellschaften ESPGHAN, ESPEN, ESPR und CSPEN: 1. Parenterale Nährlösungen, die Fette und/oder Vitamine enthalten, sind während der Applikation durch geeignete Maßnahmen vor Licht zu schützen. 2. Parenterale Nährlösungen, die keine Fette und/oder Vitamine enthalten (z. B. Lösungen mit Aminosäuren, Glucose, Elektrolyten oder Spurenelementen) bedürfen keines speziellen Lichtschutzes. 3. Bei heimparenteraler Ernährung können im Hinblick auf die kindlichen Bedürfnisse normale Spiralleitungen verwendet werden, solange lichtschützende Spiralleitungen nicht verfügbar sind.

Degradation Products of Tryptophan in Cell Culture Media: Contribution to Color and Toxicity

Biomanufacturing processes may be optimized by storing cell culture media at room temperature, but this is currently limited by their instability and change in color upon long-term storage. This study demonstrates that one of the critical contributing factors toward media browning is tryptophan. LC-MS technology was utilized to identify tryptophan degradation products, which are likely formed primarily from oxidation reactions. Several of the identified compounds were shown to contribute significantly to color in solutions but also to exhibit toxicity against CHO cells. A cell-culture-compatible antioxidant, a-ketoglutaric acid, was found to be an efficient cell culture media additive for stabilizing components against degradation, inhibiting the browning of media formulations, and decreasing ammonia production, thus providing a viable method for developing room-temperature stable cell culture media.

Editorial: Light shielding of bags and tubing used for parenteral nutrition of infants

PURPOSE OF REVIEW

In July 2019, the Pharmacovigilance Risk Assessment Committee (PRAC) of the European Medicines Agency (EMA) recommended light protection of all parenteral nutrition (PN) solutions containing amino acids (AA) and/or lipids, with or without admixture of vitamins or trace elements, during administration for preterm infants, term infants and children less than 2 years of age. The aim of the present paper was to review the available evidence and to provide recommendations for in hospital and home PN light protection in children.

RECENT FINDINGS

Lipid emulsions and multivitamins are susceptible to photooxidation and generation of oxidation products. There is no conclusive evidence to justify recommending light protection for PN solutions without lipid emulsions and/or vitamins during administration (solutions containing e.g. AA, glucose, electrolytes, or trace elements).

SUMMARY

Lipid emulsions and/or vitamins containing PN solutions should be protected from light during administration (bags and tubing) to reduce the generation of oxidation products.

Use of ammonium salts or binary mixtures derived from amino acids, glycine betaine, choline and indole-3-butyric acid as plant regulators

A simple, efficient, and environmentally friendly synthesis method for bioproducts based on indole-3-butyric acid and amino acids, glycine betaine or choline has been developed. Spectral analysis and molecular calculations were used to determine whether the products were ammonium salts or binary mixtures. Moreover, it was observed that the ammonium salts degraded more rapidly than the binary mixtures when exposed to light. The structures of the products significantly impacted their thermal stability and phase transitions. Biological studies clearly showed that the synthesized products were more effective than a reference commercial preparation as a rooting agent and have significant potential as new biologically active agents with low environmental impact.