Simultaneous quantitative determination of liraglutide and insulin degludec in rat plasma by liquid chromatography–tandem mass spectrometry method and its application

Optimized LC-MS/MS method for quantifying insulin degludec and liraglutide in rat plasma and Tissues: Application in pharmacokinetics and biodistribution

We present an ultra-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for simultaneous detection of insulin degludec (I-Deg) and liraglutide (LIRA) in rat plasma and tissues, characterized by its sensitivity and selectivity. Chromatographic separation was achieved using an Acquity UPLC BEH C18 column, leveraging a mobile phase of acetonitrile and water (both with 0.1 % formic acid) under gradient elution over a run time of 7.5 min. The mass spectrometer operated in positive electrospray ionization multiple reaction monitoring (MRM) mode, tracking transitions of m/z 1221.6 → 641.6 for I-Deg, m/z 938.7 → 1064.1 for LIRA, and m/z 1184.7 → 454.4 for the internal standard. Validation ranged from 5 to 100 ng/mL, exhibiting robust linearity (r2 > 0.99) and limits of detection (LOD) of 1.63-2.02 ng/mL for I-Deg and 0.96-1.62 ng/mL for LIRA. Limits of quantification (LOQ) were 2.38-4.76 ng/mL for I-Deg and 3.22-4.40 ng/mL for LIRA. Notably, no significant matrix effects were detected. Stability was confirmed under various conditions, and precision metrics (intraday RSD 1.68-8.05 % for I-Deg and 1.11-7.69 % for LIRA; interday RSD 1.39-8.61 % for I-Deg and 1.06-8.83 % for LIRA) alongside accuracy (90.5-114.9 % for I-Deg and 92.7-113.7 % for LIRA) were within acceptable ranges. The method was successfully applied to pharmacokinetic and biodistribution studies following simultaneous subcutaneous administration of LIRA and I-Deg in rats.

Simultaneous analysis of antihyperglycemic small molecule drugs and peptide drugs by means of dual liquid chromatography high-resolution mass spectrometry

OBJECTIVES

The study aimed to evaluate dual liquid chromatography (LC) coupled to high-resolution mass spectrometry (HRMS) for the simultaneous analysis of small and large molecule drugs by development and application of a validated bioanalytical method.

METHODS

The oral antihyperglycemic drugs (OAD) dapagliflozin, empagliflozin, glibenclamide, glimepiride, metformin, pioglitazone, repaglinide, saxagliptin, sitagliptin, and vildagliptin, as well as the antihyperglycemic peptides exenatide, human insulin, insulin aspart, insulin degludec, insulin detemir, insulin glargine, insulin glulisine, insulin lispro, and semaglutide were included in the analytical procedure. Analytes were extracted using a combination of protein precipitation and solid-phase extraction. Two identical reversed-phase columns were used for separation followed by Orbitrap high-resolution mass spectrometry. The whole procedure was validated according to international recommendations.

RESULTS

Different MS parameters had to be used for the two analyte groups, but dual LC separation allowed elution of all analytes within 12 min using the same column type. The analytical procedure was accurate and precise for most of the compounds except for exenatide, semaglutide, and insulin glargine, which were included qualitatively in the method. Analysis of proof-of-concept samples revealed OAD concentrations mostly within their therapeutic range, insulins could be detected in five cases but at concentrations below the lower limit of quantification except for one case.

CONCLUSIONS

Dual LC in combination with HRMS was shown to be a suitable platform to analyze small and large molecules in parallel and the current method allowed the determination of a total of 19 antihyperglycemic drugs in blood plasma within 12 min.

Novel LC-MS/MS analysis of the GLP-1 analog semaglutide with its application to pharmacokinetics and brain distribution studies in rats

Semaglutide, one of the most potent glucagon-like peptide (GLP)-1 analogs, has widely been used to treat type II diabetes mellitus and obesity. Recent studies have shown that semaglutide also works on the brain, suggesting its potential utility for various diseases, including Parkinson's disease and Alzheimer's disease. This study aimed to develop a novel liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis of semaglutide in both plasma and brain to characterize the pharmacokinetics and brain distribution in rats. Semaglutide was extracted by simple protein precipitation with methanol from plasma and by solid phase extraction from brain tissue. Liraglutide was used as an internal standard. Gradient elution profiles with mobile phases comprising 0.1 % formic acid in water and acetonitrile were used for chromatographic separation. The lower limit of quantification (LLOQ) of the LC-MS/MS assay was 0.5 ng/mL for both rat plasma and brain. Intra- and inter-day accuracy ranged 89.20-109.50 % in the plasma and 92.00-105.00 % in the brain. Precision was within 8.92 % in the plasma and 7.94 % in the brain. Sprague-Dawley rats were given semaglutide by intravenous (IV, 0.02 mg/kg) and subcutaneous (SC, 0.1 and 0.2 mg/kg) injection. Plasma concentrations of semaglutide showed a multi-exponential decline with an average half-life of 7.22-9.26 hr in rats. The subcutaneous bioavailability of semaglutide was 76.65-82.85 %. The brain tissue to plasma partition coefficient (K_p) value of semaglutide was estimated as <0.01. Among the different regions of the brain, semaglutide concentrations were significantly higher in the hypothalamus. The analytical method and pharmacokinetic information may be helpful toward a better understanding of the effect of semaglutide in the brain and further development of GLP-1 analogs for various brain diseases.

Simultaneous quantitative determination of insulin aspart and insulin degludec in human plasma using simple shoot LC method

Combining short-acting and long-acting insulin analogs was a real challenge that was overcome by NovoNordisk through the co-formulation of insulin aspart and insulin degludec in single-dosage form. The proposed study provides a simple, short, and reliable HPLC method with diode array detection that is developed and validated for the simultaneous determination of insulin aspart and insulin degludec in human plasma. The proposed method achieved good separation between the two analytes utilizing a C8 column at 35°C in a very short run time (6 min), with a simple, low-cost, and reliable extraction method through precipitation of plasma protein. Gradient elution was applied using a mobile phase consisting of 0.1 M sodium sulfate (pH 3.4) and acetonitrile. The method was validated according to EMA Guideline on Bioanalytical Validation. The proposed method had a linear range from 3.0 to 300 μg/mL for insulin aspart and from 3.5 to 300 μg/mL for insulin degludec. The intra- and inter-day precision of insulin aspart were 0.36-3.33% and 1.59-8.84%, respectively, and accuracy was between 10.06 and 3.09% The intra- and inter-day precision of insulin degludec were 0.29-1.93% and 0.89-5.14%, respectively, and accuracy was between -5.29 and 3.91%.

Efficacy, Pharmacokinetics, Biodistribution and Excretion of a Novel Acylated Long-Acting Insulin Analogue INS061 in Rats

Purpose

Long-acting insulin analogues are known to be a major player in the management of glucose levels in type I diabetic patients. However, highly frequent hypo- and hyperglycemic incidences of current long-acting insulins are the important factor to limit stable management of glucose level for clinical benefits. To further optimize the properties for steadily controlling glucose level, a novel long-acting insulin INS061 was designed and its efficacy, pharmacokinetics, biodistribution and excretion profiles were investigated in rats.

Methods

The glucose-lowering effects were evaluated in a streptozocin-induced diabetic rats compared to commercial insulins via subcutaneous administration. The pharmacokinetics, biodistribution, and excretion were examined by validated analytical methods including radioactivity assay and radioactivity assay after the precipitation with TCA and the separation by HPLC.

Results

INS061 exhibited favorable blood glucose lowering effects up to 24 h compared to Degludec. Pharmacokinetic study revealed that the concentration-time curves of INS061 between two administration routes were remarkably different. Following intravenous administration, INS061 was quickly distributed to various organs and tissues and slowly eliminated over time with urinary excretion being the major route for elimination, and the maximum plasma concentrations (Cmax) and systemic exposures (AUC) increased in a linear manner.

Conclusion

The present structural modifications of human insulin possessed a long-acting profile and glucose-lowering function along with favorable in vivo properties in rats, which establish a foundation for further preclinical and clinical evaluation.

A comprehensive stability assessment of insulin degludec using New customized validated RP-HPLC and SEC-HPLC methods in an orthogonal testing protocol

Stress testing of biopharmaceuticals plays an important role in preparation of their stability profiles through investigation of possible degradation pathways and identification of degradation products, so in this study Insulin Degludec which is a new generation ultra-long-acting basal insulin is subjected to stress conditions as different temperatures, different pH, oxidation, mechanical agitation, and repeated freeze and thaw cycles to generate possible degradation products and aggregation that are investigated by two new validated RP-HPLC and SEC-HPLC methods in addition to dynamic light scattering (DLS) and native polyacrylamide gel electrophoresis (Nu-PAGE). SEC-HPLC was used to investigate formation of aggregates whose results were correlated with those obtained from DLS and Nu-PAGE, while RP-HPLC was used to investigate any possible chemical modifications. The Proposed RP-method had limit of detection (LOD) and limit of quantitation (LOQ) of 0.012 mg/mL and 0.045 mg/mL respectively and accuracy of 99.22 ± 1.07 %, while the SEC methods had limit of detection (LOD) and limit of quantitation (LOQ) of 0.012 mg/mL and 0.031 mg/mL, respectively. The degradation pattern due to high temperature effect and oxidation is investigated by LC- tandem mass spectrometry. Results showed that Insulin degludec is highly stable under low temperature, mechanical agitation and repeated freeze and thaw stress conditions but elevated temperature and high acidic condition lead to formation of aggregates and also chemical modifications including deamidation, isomerization and oxidation. Such different chemical degradation pathways are due to presence of variable reactive moieties in Insulin degludec structure. Insulin degludec is highly vulnerable to oxidation at the sulfur containing cysteine residue in B chain in position B7 forming trioxidation derivative when exposed to hydrogen peroxide. Formation of A21-Asp and A18-Asp deamidated variants as well as B3-Asp and B3-isoAsp deamidated variants are prominent degradation pathways at neutral pH but at elevated temperature.