Synthetic pharmaceutical peptides characterization by chromatography principles and method development.

As per the United States Food and Drug Administration, any polymer/chain composed of 40 or fewer amino acids is called a peptide, where more than 40 amino acids are considered proteins. On many occasions, there is a change in the source of manufacturing of the peptide active pharmaceutical ingredient, where one has to prove the sameness of that product with the existing formulation by considering several aspects like the presence of impurities/degradation products, the extent of aggregations, and so forth. For the same, several chromatographic characterization techniques such as reversed-phase high-performance liquid chromatography-ultraviolet/high-resolution mass spectrometry, supercritical fluid chromatography, size-exclusion chromatography, ion-exchange chromatography, and so forth, are widely used in the pharmaceutical industry. It is well known that the method development of peptide molecules is often challenging as many variables are to be kept in mind which can affect the separation, recovery, and stability of the molecule. The present review focuses on the basics of peptide degradation and method development by using various chromatographic techniques for characterization. It also covers a deep insight of method development parameters and variables to be considered which might directly or indirectly affect the chromatographic separation and recovery and also provides a guide on the selection of chromatographic parameters.

Reactivity of N terminal histidine of peptides towards excipients/impurity of excipients: A case study of liraglutide excipient compatibility study.

The selection of quality excipients is a crucial step in peptide formulation development. Apart from excipient incompatibility, process-related impurities or degradants of an excipient can interact with peptide-active pharmaceutical ingredients, forming the interaction products. The formaldehyde has been reported as an impurity of excipient in polyethylene glycol, glycerol, magnesium stearate, microcrystalline cellulose, mannitol, etc. The peptide contains various amino acids such as histidine, lysine, and arginine having free amine groups. These amine groups act as strong nucleophile and can increase the reactivity of peptides. PLGA is the most widely used biodegradable polymer in sustained-release formulations. The hydrolysis of PLGA generates glycolic acid and lactic acid impurities, which can form the interaction product with the amines of peptides. During the formulation development of Liraglutide, we have found few interaction products. The systematic characterization and mechanistic understanding of these interaction products lead us to imidazopyrimidine, glycolyl, and lactolyl moieties. These interaction products have been characterized thoroughly with the use of LC-HRMS, MS/MS, and hydrogen-deuterium exchange mass studies. The study revealed that the reactivity of N-terminal histidine must be considered for formulation development. Moreover, the quality of excipients with respect to presence of impurities must be considered as critical material attributes.

Cancer stem cell biomarkers SOX2 and Oct4 in cervical cancer patients undergoing chemoradiotherapy.

BACKGROUND: Cancer stem cell biomarkers SRY (sex-determining region Y)-box 2 (SOX2) and octamer-binding transcription factor 4 (Oct4) account for radioresistance in cervical squamous cell cancers (CSCCs). Their clinical implications are limited and contradictory. METHODS: In this prospective cohort study, we recruited patients with FIGO IB2-IVA CSCC treated with primary chemoradiotherapy on regular follow-up. Tissue biopsy specimens were evaluated for SOX2 and Oct4 expression by immunohistochemistry, quantified by a product of proportion and intensity scores. RESULTS: A total of 59 patients were included. Most had a moderately differentiated (81%), keratinizing (59%) CSCC, and ≥FIGO stage IIB disease (95%). SOX2 expression (high:low 21:38 patients) and Oct4 expression (high:low 4:55 patients) had a significant interrelation (p = 0.005, odds ratio (95% CI) - 1.23 (1.004-1.520)). At a median follow-up of 36 months, the 3-year overall survival (OS) was 60% and 53% for low and high SOX2 expression (p = 0.856), and 54% and 100% for low and high Oct4 expression (p = 0.114). The 3-year disease-frese survival (DFS) was 65% and 50% in the low and high SOX2 expression (p = 0.259), and 59% and 75% for low and high Oct4 expression (p = 0.598). SOX2 expression was the only variable significantly associated with a lower OS and DFS on regression analysis. CONCLUSION: Our study demonstrated a trend toward improved OS and DFS with low SOX2 and high Oct4 expression in CSCC patients undergoing chemoradiotherapy.

An audit of uterine perforation and its effect on the final outcome in an academic research medical center: An optimized balance between overall treatment time and medical crisis.

Purpose: Intra-cavitary brachytherapy is an integral component of cervical cancer management, and uterine perforation is the most significant complication, which may lead to prolonged overall treatment time and decreased local control in these patients. Material and methods: A retrospective analysis of cervical cancer patients who completed radiotherapy (external beam radiotherapy and brachytherapy) in our department was conducted to determine the incidence, effect on overall treatment time, and final outcome in patients with uterine perforation during brachytherapy procedure. Results: Among 55 women, of the 398 applications, 85 (21.36%) resulted in uterine perforation. Out of these 85 applications, treatment time was extended among 3 (3.5%) applications only, as re-insertion was done nearly after one week, while the remaining 82 (96.5%) applications were completed in time. At the time of analysis, the median follow-up was 12 months, and 32 patients were disease-free, 3 had distant metastatic disease, 2 had residual disease, and 18 were lost to follow-up. Conclusions: In our study, uterine perforation incidence was found to be comparable with other centers worldwide. In asymptomatic and uncomplicated uterine perforation, treatment can be continued with computer-based optimized treatment plans without loading a specific dwell position and without affecting overall treatment time.