Identification of an Adduct Impurity of an Active Pharmaceutical Ingredient and a Leachable in an Ophthalmic Drug Product Using LC-QTOF.

Impurity investigations are important in pharmaceutical development to ensure drug purity and safety for the patient. The impurities typically found in drug products are degradants or reaction products of the active pharmaceutical ingredient (API) or leachable compounds from the container closure system. However, secondary reactions may also occur between API degradants, excipient impurities, residual solvents, and leachables to form adduct impurities. We hereby report an adduct-forming interaction of API (moxifloxacin) with a leachable compound (ethylene glycol monoformate) in moxifloxacin ophthalmic solution. The leachable compound originated from a low-density polyethylene bottle used in the packaging of drug products. The adduct impurity was tentatively identified as 1-cyclopropyl-6-fluoro-7-(1-(2-(formyloxy)ethyl) octahydro-6H-pyrrolo[3,4-b]pyridin-6-yl)-8-methoxy-4-oxo-1,4-dihydroquinoline-3-carboxylic acid (C24H28FN3O6, MW = 473.19621) using accurate mass LC-QTOF analysis. The mass accuracy error between the theoretical mass and the experimental mass of an impurity was found to be 0.2 ppm. An MS/MS analysis was utilized to provide mass spectrometry fragments to support verification of the proposed structure.

Plasma alpha2-HS glycoprotein concentrations in patients with acute myocardial infarction quantified by a modified ELISA.

BACKGROUND: Human alpha2-HS glycoprotein (alpha2-HSG) is synthesized and secreted by the liver into circulation. Plasma concentrations of alpha2-HSG decrease significantly following infection, inflammation and malignancy. Since increased plasma concentrations of C-reactive protein are observed in patients with acute myocardial infarction (AMI), we hypothesized that plasma concentrations of alpha2-HSG would decrease during the initial phase of AMI and begin to increase in the recovery phase. METHODS: Twenty patients diagnosed with AMI were recruited for the study. A sensitive and specific ELISA was developed to assay alpha2-HSG concentrations in plasma. RESULTS: In AMI patients, plasma alpha2-HSG concentrations were decreased (281.3+/-25.8 mg/l, ranging from 132 to 489 mg/l on admission) compared to healthy individuals (312.3+/-9.9 mg/l, ranging from 210 to 450 mg/l) (P= 0.142). Interestingly, 40% of AMI patients demonstrated alpha2-HSG concentrations below 200 mg/l compared to none in the healthy control group. During the recovery period, alpha2-HSG concentrations begin to increase, with a mean+/-SEM of 290.1+/-22.1 mg/l. Regression analysis comparing plasma alpha2-HSG concentrations on admission to concentrations on discharge showed a significant positive correlation in matched-pair patient samples (P<0.01, r=0.45). CONCLUSIONS: We conclude that, in contrast to C-reactive protein, alpha2-HSG functions as a negative acute phase protein in AMI patients. Plasma alpha2-HSG concentrations start to decrease within a few hours after the onset of AMI and return to near normal concentrations during the recovery period (5-7 days after AMI).