Simultaneous Estimation of Genotoxic Impurities 4-Nitrobenzene Trifluoride, 4-Aminobenzene Trifluoride, and Benzo Trichloride in Cinacalcet Hydrochloride by GC-MS/MS Method

The main objective of this study is to develop and validate a novel, fast, and more sensitive gas chromatography-mass spectrometry (GC-MS/MS) method for the simultaneous estimation of 4-Nitrobenzotrifluoride (4-NBTF), 4-Amino-benzotrifluoride (4-ABTF), and Benzotrichloride (BTC) impurities in Cinacalcet hydrochloride (CH). The chromate-graphic separations were performed on a DB-624, 30m × 0.32mm × 1.8µm column with injector temperature of 150°C, and mode of injection is split with asplit ratio 1: 20. The carrier gas used was helium with a flowrate 1.5 mL/min, and theinjection load was 1.0 µL. Mass spectrometry quantitation was achieved by aquadrupole analyser with EI (Electron Ionization) ion source atasource temperature of 250ºC and interface temperature of 250ºC. The retention times for 4-NBTF, 4-ABTF, and BTC were at 6.13, 6.74and 7.64min, respectively. The calibration curve was linear over the concentration ranging from LOQ level to 150 % level with the correlation coefficient (r) of > 0.99. The percentage recovery was found to be within the specified range, i.e., 70.0 to 130.0 for the three impurities. The limit of detection (LOD) was established to 0.19, 0.19, and 0.18 ppm, whereas thelimit of quantification (LOQ) was obtained to 1.14, 1.12, and 1.11 ppm for 4-NBTF, 4-ABTF, and BTC, respectively. The test solutions with impurities were found to be stable in the diluent for 24 hours. A simple GC-MS/MS method was developed and validated for simultaneous estimation of three impurities in CH. The method was accurate, precise, linear, specific, sensitive, robust, and rugged as per ICH guidelines. The method has been applied to the real-time batch analysis and found to be suitable for routine quality control analysis of CH.

A case of a hemodialysis patient with secondary hyperparathyroidism who was resistant to etelcalcetide treatment but not to cinacalcet hydrochloride

Although both cinacalcet and etelcalcetide are calcimimetics that directly inhibit parathyroid hormone (PTH) secretion by activating the calcium (Ca)-sensing receptor (CaSR), their binding sites are different. We report a first case of a hemodialysis (HD) patient with secondary hyperparathyroidism (SHPT), in whom cinacalcet, but not etelcalcetide, could reduce serum intact PTH (i-PTH) levels. A HD patient received total parathyroidectomy (PTx) with auto-transplantation 16 years earlier. Due to SHPT relapse, cinacalcet was started at 7 years after PTx. His i-PTH levels had been controlled with both 75–100 mg of cinacalcet and 4.5 μg/week of calcitriol for a year before switching from cinacalcet to etelcalcetide. At 1 month following the switch, his serum i-PTH level increased to 716 pg/mL. The dose of etelcalcetide was gradually increased and finally reached the maximal dose of 45 mg/week. Because even the maximal dose of etelcalcetide for > 4 months did not reduce his serum i-PTH levels to < 700 pg/mL, etelcalcetide was switched to 50 mg/day of cinacalcet, which reduced the levels to 208 pg/mL at 2 months after the switch. Genomic sequencing test using whole blood revealed no mutation in the portion including Cys 482 of CaSR gene. The patient was resistant to etelcalcetide treatment but not to cinacalcet, suggesting the possibility that the enlarged parathyroid gland has some change in the portion including Cys 482 in the CaSR gene. Therefore, considering the possibility of etelcalcetide resistance during SHPT treatment should be kept in mind.

Chemometrics and Monte-Carlo Simulation Assisted RP-LC Method for Estimation of Cinacalcet Hydro- chloride in Pharmaceutical Products

Cinacalcet hydrochloride (CNT) is a novel calcimimetic agent widely used in the treatment of hyperparathy- roidism. For the first time, the authors utilized the novel concept of analytical procedure development employing several unique scientific tools for quantification CNT from its pharmaceutical dosage form. The objective behind the present work was to establish a scientifically sound and systematic work frame that overcomes the drawbacks of the earlier reported method for estimating CNT level in samples and ensuring superior method performance throughout the analytical life-cycle. In this process, at first, the risky method variables were earmarked and were subjected to a response surface methodology, followed by Monte-Carlo simulation (MCS) based robust- ness-cum-optimization studies. The inclusion of the MCS approach assessed the method performance with no additional laboratory experimentation and established the innovative hyphenation's aptness with chemometrics tools. The control strategies were established based on analytical design space and method performance evaluation results by a simulative approach. The study revealed that methanol %, flow rate, and pH are the three critical method variables influencing analytical attributes: retention time, the number of plates, and tailing. The analytical conditions include a C18 column (150mm × 4.6mm, 5μm) with an isocratic mobile phase (80:20, % v/v) of methanol and 0.01M KH2PO4 buffer (pH maintained at 3.5 using orthophosphoric acid) flowing at 1.1ml/min. Diode array detection was performed at 282 nm. Method validation was befitting to federal needs as linearity (0.5-160 μg/ml), accuracy (>99%), and precision below 1% of relative standard deviation are indicative of method suitability for the purpose. In a nutshell, the present method describes a typical analytical workflow with the significant advantage of obtaining more excellent scientific information with less systematized experimentation. It was found suitable for routine quality control of CNT in drug substance and drug product.

Oxidation of Cinacalcet Hydrochloride by Chloramine-B in Acid Medium: A Kinetic and Mechanistic Study

Kinetic and mechanistic study of cinacalcet hydrochloride by chloramine-B (CAB) in HCl medium at 308 K was the aim of this work. Analyzed the reaction at five different temperatures and determined the thermodynamic parameters using Arrhenius plots. The reaction had a stoichiometry of 1:2 and characterized the oxidation product using chromatographic and spectroscopic methods. The rate law is deduced from the marked effects, which were accompanied by plausible mechanisms.

Development and Validation of Stability Indicating RP-HPLC Method for the Estimation of Cinacalcet Hydrochloride in Bulk and Their Formulations

A Simple, selective, accurate, precise, linear, and stability-indicating RP-HPLC method was developed and validated for the estimation of Cinacalcet hydrochloride in bulk and tablet dosage forms. Chromatographic separation was achieved on X-Terra Symmetry C18 (4.6 x 150mm; 5 m) with mobile phase containing Phosphate buffer: Acetonitrile (40:60 v/v) pH adjusted to 3.0 ±0.05 with diluted ortho-phosphoric acid. The flow rate was maintained at 0.9 mL/min. The eluent was monitored at 282 nm. Moreover, the retention time of Cinacalcet was 2.8 minutes. The method was validated for linearity, accuracy, precision, and robustness as per ICH guidelines. The developed method was found linear between 25-150 μg/ml, and the linear regression coefficient was 0.999. The % RSD values are less than 2 % indicating the accuracy and precision of the method. The percentage of recovery was obtained from 98-102%. The system suitability parameters were found to be within the limit. Forced degradation studies were conducted under various conditions. The proposed method is simple, rapid, precise, and accurate. It can be used for the quantitation of Cinacalcet hydrochloride in bulk and commercial pharmaceutical dosage forms.