Comprehensive characterization of bremelanotide acetate and its degradants by LC-HRMS/MS and predicting epimerization through computational modelling.
Bremelanotide showed lower degradation under acidic conditions and significant susceptibility to oxidative conditions, with eight degradation products identified.
Where it sits
this study against the rest of the pt-141 (bremelanotide) corpusSummary and findings
This study investigated the stability and degradation behavior of bremelanotide (BRM) under various stress conditions. The research involved the development of a stability-indicating RP-HPLC method and characterization of degradation products using LC-HRMS/MS. Eight degradation products were identified, with significant susceptibility to oxidative conditions noted.
Abstract
Bremelanotide (BRM) is a cyclic peptide therapeutic whose intrinsic stability and degradation behavior have not been extensively investigated. This study aimed to develop a stability-indicating RP-HPLC method for BRM and characterize its degradation products using LC-HRMS/MS combined with computational approaches. Stress degradation studies were conducted according to International Council for Harmonization guidelines under acidic, basic, neutral hydrolytic, oxidative, thermal, and photolytic conditions. The RP-HPLC method was developed using a YMC Pack C8 column with 10 mM ammonium formate buffer (pH 3.0) and acetonitrile containing 0.1% formic acid as the mobile phase in gradient mode. The method was partially validated and showed satisfactory system suitability, precision, and accuracy. Excellent linearity was achieved over 25-150 µg mL<sup>-1</sup> with a coefficient of determination (<i>r</i><sup>2</sup>) of 0.9993. Forced degradation studies revealed that BRM exhibited lower degradation under acidic conditions compared with basic conditions and showed significant susceptibility to oxidative conditions. Furthermore, degradation was also observed under thermal and photolytic stress conditions. A total of eight degradation products were detected and characterized by LC-HRMS/MS. The major degradation pathways involved deacetylation, peptide-bond hydrolysis, oxidation, and epimerization. Epimerized products were identified, and probable stereochemical sites were predicted using energy minimization by correlating steric energies with MS/MS fragment relative intensities. ProTox-3.0-based <i>in silico</i> toxicity prediction indicated that most degradation products belonged to toxicity class 5, while two hydrolytic products were classified as class 4. Overall, this study provides valuable insights into BRM stability behavior and supports peptide API/formulation development, impurity profiling, and quality control.
Background
The paper addresses the stability and degradation of bremelanotide acetate, a peptide that has garnered interest for its potential applications. Prior studies have indicated varying stability profiles for peptides, which can significantly impact their efficacy and safety. Understanding the degradation pathways and stability of bremelanotide is crucial for its development and application in clinical settings.
Methods
The study utilized liquid chromatography-high resolution mass spectrometry (LC-HRMS/MS) to analyze bremelanotide acetate and its degradants. The specific population or model used, sample size, dose, and duration of the study were not reported in the abstract. The primary outcome measures focused on the characterization of the compound and its degradation products.
Results
Not reported in abstract.
Interpretation
The findings may contribute to the existing literature on peptide stability, although the lack of specific numeric results limits the ability to assess the clinical significance of the findings. Without clear effect sizes or comparisons to prior studies, the implications for practice remain uncertain. Potential confounds include the absence of detailed methodology and results, which could affect the reliability of the conclusions drawn.
Key findings
- Not reported in abstract.
Limitations
- Not reported in abstract.