The first RP-UHPLC method for simultaneous quantification of abiraterone acetate, its four degradants, and six specified process impurities and correct identification of all analytes based on molecular weight.

This article describes the first simple, fast, time-saving, and cost-effective UHPLC method that was developed and validated for simultaneous quantification of abiraterone acetate, its four degradation products, and six specified process impurities in bulk and tablet form. Moreover, when coupled with a mass spectrometer detector, the proposed method provides additional advantages for confirmation of peak and correct identification based on molecular weight. The eleven peaks were separated on a Water Acquity BEH C18, (150 mm length, 2.1 mm internal diameter, 1.7 µm particle size) column maintained at a 50.0 °C temperature. Using 0.05% formic acid in 10 mM ammonium formate, acetonitrile, and methanol as mobile phases in gradient elution at a flow rate of 0.40 mL/min. provides excellent separation at 260 nm. The linearity curves of all analytes showed promising results with a correlation coefficient of 0.999 with a lower limit of detection and quantification. A forced degradation study on solid abiraterone acetate proved its specificity with improvements and significance. This proposed method provides improved separation with a lower flow rate, which offers faster analysis, reduces wastage and cost, and specifies the greener advantages compared to reported methods. The outcome of the specificity, linearity, precision, and trueness as per ICH guidelines proved that the proposed method is fast, time-saving, and cost-effective for the intended purpose.

Simultaneous quantification of (E) and (Z) isomers of rilpivirine and four degradation products in bulk and tablets by reversed-phase ultra-high-performance liquid chromatography and confirmation of all by molecular weight.

The (E)-isomer of rilpivirine is an approved antiretroviral drug used to treat human immunodeficiency virus. A simple, fast, accurate, and precise analytical method is required to confirm the quality, purity, efficacy, and safety of drug substances and drug products containing rilpivirine. This research article offers a comprehensive ultra-high performance liquid chromatography method for the simultaneous separation and quantification of (E) and (Z) isomers of rilpivirine, including two amide impurities, one nitrile impurity, and one dimer impurity, in both bulk and tablet forms. After complete validation, the proposed reversed-phase ultra-high-performance liquid chromatography method has proven to be simple, fast, linear, accurate, and precise, with a lower limit of quantification and detection of 0.05 and 0.03 µg/ml, respectively, for all six analytes. Separation was achieved on a Waters Acquity ethylene bridged hybrid Shield RP18 (150 × 2.1 mm, 1.7 µm) column maintained at 35.0°C using a gradient elution of acetonitrile and 0.05% formic acid in 10 mM ammonium formate at a flow rate of 0.30 ml/min. A systematic forced degradation study on the undissolved rilpivirine revealed the formation of acid-base hydrolyzed amide impurities (Impurity-A and Impurity-B), oxidative nitrile impurities (Impurity-C), and Z-isomer and dimer impurities of rilpivirine (Impurity-D and Impurity-E) due to alkaline hydrolysis and photodegradation. The proposed method is primarily appropriate for applications requiring the precise determination of desired and undesired isomers of rilpivirine and its degradation products, such as those involving the safety, efficacy, and quality roles of rilpivirine in bulk and tablet forms. Additionally, the proposed ultra-high-performance liquid chromatography method in combination with a mass spectrometer and photo-diode array detector is helpful for the confirmation and correct identification of all analytes.

Radiological tumor density and lymph node size correlate with survival in resectable adenocarcinoma of the pancreatic head: A retrospective cohort study.

INTRODUCTION: Tumors within the pancreatic head show a variable density and enhancement on computerized tomography (CT). The relationship between the radiological appearance of pancreatic adenocarcinoma on CT and survival remains unclear. The aim of this study was to evaluate the relationship between the tumor density on CT and survival. We also evaluated the correlation between lymph node (LN) size and overall survival in patients undergoing pancreaticoduodenectomy for head of pancreas adenocarcinoma. MATERIALS AND METHODS: Case records of patients undergoing pancreaticoduodenectomy for the adenocarcinoma of pancreas head, between 2005 and 2009, were evaluated. CT was interpreted to document tumor density - Hounsfield unit (HU) and LN size of enlarged LNs. Histology was analyzed to review tumor differentiation and LN status. Survival was correlated with LN size and tumor density (HU). RESULTS: Increasing tumor density was significantly associated with an adverse outcome (P = 0.042, hazard ratio [HR] 1.034, 1.002-1.067 95% confidence interval [95% CI]). Patients with well-differentiated tumors had significantly lower tumor density as compared to moderately differentiated tumors (39.00 ± 26.00 vs. 71.31 ± 21.03 HU, P = 0.005). LN size more than 1 cm irrespective of LN status strongly correlated with the survival and was found to be an important prognostic factor (19.37 ± 2.71 months vs. 27.44 ± 2.74 months; P = 0.025; HR 2.70; 1.09-6.68 95% CI). CONCLUSION: Increasing pancreatic tumor density and the lymph nodal size of more than 1 cm are strong predictors of unfavorable overall survival for resectable adenocarcinoma of the pancreatic head. Further studies are required to identify the value of these proposed prognostic factors.