Development of a Stability-Indicating Purity Method for Ubrogepant Through Stress Degradation Analysis, Extraction, and Characterization of Unidentified Degradation Products Using Flash Chromatography, NMR, IR, and LC-MS

BACKGROUND

Ubrogepant is a prescription medication used to prevent migraine headaches. It is currently available in tablet form.

OBJECTIVE

The goal of this work is to investigate the drug degradation profile of ubrogepant, as well as to isolate and characterize undiscovered ubrogepant degradation products by utilizing LC-MS, NMR, and IR spectroscopic analytical techniques and, furthermore, to develop a high-resolution, sensitive, stability-indicating analytical approach for detecting and quantifying ubrogepant degradation products in its pharmaceutical formulation.

METHODS

To identify and quantify the degradation products of ubrogepant in pharmaceutical products, a novel gradient reverse-phase HPLC (RP-HPLC) technique with a photo diode array (PDA) detector was developed by utilizing a C18 stationary phase column. The eluent comprised a mixture of acetonitrile and water with 0.1% (v/v) ortho-phosphoric acid. To establish the intrinsic stability of the ubrogepant pharmaceutical product, it was stress-tested under various degradation conditions, including water, alkaline, acid hydrolysis, photolytic, oxidative, and thermal. Flash chromatography was used to isolate the two major degradants, and the structures were determined using NMR (1H, 13C, distortionless enhancement by polarisation transfer-DEPT-135), IR, and LC-MS methods.

RESULTS

The ubrogepant medication was relatively more degradable in alkaline and acidic conditions, and two unique degradation products were discovered. Based on spectroscopic and chromatographic evidence, it was conclusively demonstrated that these unique compounds were ubrogepant hydrolysis products. All degradation products were separated with a resolution greater than 2.0. The peak purity data showed that the ubrogepant peak in all of the stress samples examined was pure. Under all stress environments, ubrogepant achieved a minimum mass balance of 95%. The validated approach developed was sensitive enough to quantify ubrogepant degradation products at 0.03% of the ubrogepant test concentration.

CONCLUSION

The proposed method was found to be stability-indicating since it fits all of the regulatory authorities' typical requirements. This method is highly efficient for detecting and quantifying impurities in ubrogepant drug substances and drug products in QC laboratories.

HIGHLIGHTS

Two new degradation products of ubrogepant were successfully extracted and characterized using NMR, IR, and LC-MS spectroscopic methods. The proposed HPLC method can accurately quantify the degradation products of ubrogepant in pharmaceutical products and is sensitive enough to detect degradation products of ubrogepant as low as 0.17 µg/mL.

Development, evaluation of critical method variables and stability assessment using a Box-Behnken design for the determination of organic impurities in a pharmaceutical dosage form of a centrally acting muscle relaxant drug chlorzoxazone

This study validates a stability-indicating LC method for detecting organic impurities in the chlorzoxazone dosage form. Using a Waters X-Select R HSS T3 analytical column, mobile phase of it was made by mixing of water, methanol, and glacial acetic acid in the ratio of 700:300:10 (v/v/v). The drug product and drug substance were subjected to the stress conditions such as acid, base, oxidation, heat, and photolysis as per the recommendations of the International Conference on Harmonization (Q2) methodology. The study revealed the susceptibility of 4-chloro-2-aminophenol to alkaline environments, emphasizing peak homogeneity and stability. The method verification, per ICH guidelines and USP<1225>, established precision, specificity, linearity, accuracy, and robustness for quality control. The mean impurity recovery ranged from 95.5% to 105.2%, the correlation coefficient (r) was greater than 1.000, and the RSD values (n = 6) ranged from 0.6% to 5.1% across the LOQ-150% ranges. Full-factorial design tested final method conditions, evaluating multiple parameters concurrently. Graphical optimization within the design space defined strong method requirements, ensuring consistent and reliable outcomes. The study develops and validates chlorzoxazone stability-indicating methods, employing advanced statistical approaches like design of experiments and factorial design, with resilient conditions established through graphical optimization of the design space.

Development of HPLC Method for Ixabepilone (Oncology Drug) in Bulk and Dosage Form: Quantification of Impurities and Forced Degradation Studies

The objective of study is to develop a new stability-indicating HPLC method for quantifying ixabepilone degradation products and known process impurities (EPO-2 and Epothilone B) in bulk and injectable dose forms. A gradient stability-indicating RP-HPLC approach was developed to determine the known impurities of ixabepilone in ixabepilone API and ixabepilone for injection. Ixabepilone was subjected to base, acid, oxidation, photolytic and thermal degradations. The gradient approach was used to optimize the mobile phase-A [pH 4.8 acetate buffer (10 mM) and acetonitrile 90:10 v/v] and mobile phase-B [pH 4.8 acetate buffer (10 mM) and acetonitrile 20:80 v/v] of a USP L1 column. A wavelength of 250 nm was chosen based on known impurities and degradation products response, with a 1.0 mL/min flow rate. In compliance with ICH criteria Q2(R1), the developed technique was validated. The stability-indicating-related impurities technique was proven to be appropriate for estimating degrading impurities and known impurities in ixabepilone API and ixabepilone injection.

Structural Elucidation of Novel Degradation Impurities of Ibrutinib in Ibrutinib Tablets Using Preparative Chromatography, LCMS, HRMS and 2D NMR Techniques

Ibrutinib is an orally administered compound that functions as an irreversible covalent inhibitor of the Bruton tyrosine kinase, an essential element in multiple cellular processes including B-cell differentiation, proliferation, migration, survival and apoptosis. The compound has been found to demonstrate efficacy against a range of B-cell malignancies. The drug product is available in oral tablet and capsule formulations. The drug degradation profiles of tablets dosage form were assessed in accordance with regulatory guidelines. The results indicate that the drug substance is susceptible to alkaline and oxidative stress. The oxidation degradation led to the identification of three significant unknown degradation impurities. The three compounds were isolated through the application of preparative liquid chromatography, and their structures were determined using analytical techniques such as liquid chromatography-mass spectrometry, high-resolution mass spectrometry and nuclear magnetic resonance spectroscopy. Utilizing structural elucidation data, predictions were made regarding the composition of impurities, revealing them to be novel degradation impurities that bear structural resemblance to ibrutinib. Additionally, potential pathways for the formation of the impurities were proposed.

Co-Delivery Nanomicelles for Potentiating TNBC Immunotherapy by Synergetically Reshaping CAFs-Mediated Tumor Stroma and Reprogramming Immunosuppressive Microenvironment

Purpose

Immune checkpoint inhibitors (ICI) have received the most attention for triple negative breast cancer (TNBC), while the response rate to ICI remains limited due to insufficient T cell infiltration. It is therefore essential that alternative strategies are developed to improve the therapeutic outcomes of ICI in non-responsive TNBC cases. The efficacy of pH-responsive nanomicelles (P/A/B@NM) co-loaded with paclitaxel (PTX), CXCR4 antagonist AMD3100, and PD-1/PD-L1 inhibitor BMS-1 activating the T cell-mediated antitumor immune response were evaluated using a 4T1 antiPD-1-resistance breast tumor model.

Methods

In vitro, pH-responsive antitumor effect of P/A/B@NM was investigated by assessing cell viability, migration and invasion. In vivo, the distribution of P/A/B@NM was visualized in 4T1 orthotopic TNBC model using an IVIS spectrum imaging instrument. The efficacy of the co-delivery nanocarriers was evaluated by monitoring mouse survival, tumor growth and metastasis, cancer-associated fibroblasts (CAFs)-mediated tumor stroma and immunosuppressive microenvironment components, and the recruitment and infiltration of CD8+ T cells.

Results

The prepared P/A/B@NM in acid microenvironment demonstrates remarkable cytotoxicity against MDA-MB-231 cells, with an IC50 of 105 μg/mL. Additionally, it exhibits substantial inhibition of tumor cell migration and invasion. The P/A/B@NM based on co-delivery nanocarriers efficiently accumulate at the tumor site and release the drugs in a pH-responsive controlled manner. The nanomedicine-PTX, AMD3100, and BMS-1 formulation significantly inhibits tumor growth and lung/liver metastasis by inducing antitumor immune responses via CXCL12/CXCR4 axis blockade, and immunogenic cell death to reprogramme both tumor stroma and immunosuppressive microenvironment. As a result, CD8+ T cell infiltration is triggered into the tumor site, boosting the efficacy of ICI therapy synergistically.

Conclusion

These results demonstrate that combination therapy using P/A/B@NM reshapes CAFs-mediated tumor stroma and immunosuppressive microenvironment, which can enhance the infiltration of CD8+ T cells, thereby reactivating anti-tumor immunity for non-responsive TNBC cases.

CXCR4-Receptor-Targeted Liposomes for the Treatment of Peritoneal Fibrosis

Peritoneal fibrosis (PF) is a common complication of long-term peritoneal dialysis (PD). It is considered as the main reason for dialysis inadequacy and PD withdrawal. Transforming growth factor beta (TGF-β) regulates the expression of stromal cell-derived factor 1 (SDF-1α) and its receptor C-X-C chemokine receptor type 4 (CXCR4) on human peritoneal mesothelial cells (HPMCs), resulting in an increased migratory potential of HPMCs and extracellular matrix (ECM) deposition in the scar tissue and eventually fibrosis. Because SDF-1α/CXCR4 activation has a vital role in the pathogenesis of PF, codelivery of a CXCR4-receptor targeting agent with an antifibrotic agent in a single nanocarrier can be a promising strategy for treating PF. Here, for the first time, AMD3100 (AMD), a CXCR4-receptor antagonist, was coformulated with sulfotanshinone IIA sodium (STS IIA) into a liposome (STS-AMD-Lips) to develop a CXCR4 receptor targeting form of combination therapy for PF. CXCR4 targeting increased the ability of liposomes to target fibrotic peritoneal mesothelial cells overexpressing CXCR4 and facilitated the ability of STS IIA treatment at the fibrotic site. The liposome had an average diameter of 103 nm with encapsulated efficiencies of above 50%. The in vivo studies confirmed the reversal of PD solution-induced epithelial-to-mesenchymal transition by STS-AMD-Lips in HPMCs. The in vivo studies also revealed the precise biodistribution of the liposomes to peritoneum. Significant reduction of the morphological lesions and decreased level of ECM proteins were observed in rats treated with STS-AMD-Lips, proving that the liposomal nanocarrier has excellent ability to reverse PF. It has been concluded that the STS-AMD-Lips exhibit specific peritoneal targeting ability and could be used to improve STS-AMD combination delivery for the treatment of PF.