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.

Catalysts of Healing: A Symphony of Synthesis and Clinical Artistry in Small-Molecule Agents for Breast Cancer Alleviation

Breast cancer, characterized by its molecular intricacy, has witnessed a surge in targeted therapeutics owing to the rise of small-molecule drugs. These entities, derived from cutting-edge synthetic routes, often encompassing multistage reactions and chiral synthesis, target a spectrum of oncogenic pathways. Their mechanisms of action range from modulating hormone receptor signaling and inhibiting kinase activity, to impeding DNA damage repair mechanisms. Clinical applications of these drugs have resulted in enhanced patient survival rates, reduction in disease recurrence, and improved overall therapeutic indices. Notably, certain molecules have showcased efficacy in drug-resistant breast cancer phenotypes, highlighting their potential in addressing treatment challenges. The evolution and approval of small-molecule drugs have ushered in a new era for breast cancer therapeutics. Their tailored synthetic pathways and defined mechanisms of action have augmented the precision and efficacy of treatment regimens, paving the way for improved patient outcomes in the face of this pervasive malignancy. The present review embarks on a detailed exploration of small-molecule drugs that have secured regulatory approval for breast cancer treatment, emphasizing their clinical applications, synthetic pathways, and distinct mechanisms of action.

Tissue distribution and tumor uptake of folate receptor-targeted epothilone folate conjugate, BMS-753493, in CD2F1 mice after systemic administration

To assess targeting of an epothilone folate conjugate (BMS-753493) to the folate receptor (FR)-overexpressed tumor in mice bearing both FR+ and FR– tumors, a series of experiments were conducted by quantitative whole-body autoradiography (QWBA) and LC–MS/MS following i.v. administration of BMS-753493 or its active moiety, BMS-748285 in mice bearing FR+ (98M109) and FR– (M109) tumors. QWBA showed [³H]BMS-753493–derived radioactivity was extensively distributed to various tissues. The FR over-expressing 98M109 tumors showed consistently higher level of radioactivity than FR-negative tumors (i.e., M109 tumors) up to 48 h post dose of [³H]BMS-753493, despite the magnitude of difference between the tumors is relatively small (generally 3~5-fold). The radioactivity level in 98M109 tumors was 2~12-fold of normal tissues except intestine/content at 48 h post dose. No selective radioactivity uptake into 98M109 tumors over M109 or normal tissues was observed after i.v. administration of the active epothilone, [³H]BMS-748285. LC–MS/MS measurements demonstrated that the concentrations of BMS-748285, presumably from hydrolysis of the folate conjugate, in 98M109 tumors were greater than those in M109 tumors after i.v. administration of BMS-753493 (2–3-fold) whereas no differential uptake in the tumors following BMS-748285 administration. Those data were consistent with radioactivity determinations. Those results demonstrated that the folate conjugation in BMS-753493 enabled moderately preferential distribution of the active epothilone to FR over-expressing 98M109 tumors, thereby supporting targeted delivery of cytotoxics through the folate receptor.