Functional similarity of modified cascade impactor to deposit drug particles on cells.

Pulmonary drug delivery is a non-invasive and effective route for local or systemic drug administration. Despite several products in the market, the mechanism of drug absorption from the lungs is not well understood. An in vitro model for aerosol deposition and transport across epithelia that uses particle deposition may be a good predictor of and help understand in vivo drug disposition. The objective of this study was to examine the uptake of HFA fluticasone (Flovent HFA) particles at various stages of the Next Generation Impactor (NGI) by human Calu-3 cell line derived from human bronchial respiratory epithelial cell monolayer. Particles were directly deposited on Calu-3 cells incorporated onto stages 3, 5, and 7 of the NGI at the air-liquid interface (ALI). We modified the NGI apparatus to allow particle deposition directly on cells and determined the in vitro deposition characteristics using modified NGI. Particles of different size ranges showed different in vitro epithelial transport rates. This study highlights the need to develop in vitro test systems to determine the deposition of aerosol particles on cell monolayers by simultaneously considering aerodynamic properties.

Trace level determination of chloroacetyl chloride and degradation products by derivatization gas chromatography.

A gas chromatographic procedure has been developed for the trace determination of chloroacetyl chloride (CAC) and two of its impurities: methyl chloroacetate (MCA) and chloroacetic acid (CAA). All three compounds are derivatized using piperidine in dichloroethane prior to their analysis via gas chromatography coupled with a flame ionization detection (GC-FID). Recoveries of each compound were assessed in two different pharmaceutical matrices (intermediate and final active pharmaceutical ingredient) and ranged from 75 to 125%. The limit of quantitation has been determined to be 0.10% wt/wt for CAA and 0.03% wt/wt for CAC and MCA. The linearity ranged from 0.03 to 5.00% wt/wt for CAC and MCA and from 0.10 to 5.00% wt/wt for CAA, with correlation coefficients from 0.9995 to 1.0000. Repeatability was evaluated at LOQ and at 5.00% wt/wt and was found to be between 1.4-3.0%.

Free and conjugated estrogen exports in surface-runoff from poultry litter-amended soil.

Land application of animal manures such as poultry litter is a common practice, especially in states with surplus manure. Past studies have shown that animal manure may contain estrogens, which are classified as endocrine-disrupting chemicals and may pose a threat to aquatic and wildlife species. We evaluated the concentrations of estrogens in surface runoff from experimental plots (5 x 12 m each) receiving raw and pelletized poultry litter. We evaluated the free (estrone, E1; 17beta-estradiol, E2beta; estriol, E3) and conjugate forms (glucuronides and sulfates) of estrogens, which differ in their toxicity. Sampling was performed for 10 natural storm events over a 4-mo period (April-July 2008). Estrogen concentrations were screened using enzyme-linked immunosorbent assay (ELISA), followed by quantification using liquid chromatography with tandem mass spectrometry (LC/MS/MS). Concentrations of estrogens from ELISA were much higher than the LC/MS/MS values, indicating crossreactivity with organic compounds. Exports of estrogens were much lower from soils amended with pelletized poultry litter than the raw form of the litter. No-tillage management practice also resulted in a lower export of estrogens with surface runoff compared with reduced tillage. The concentrations and exports of conjugate forms of estrogens were much higher than the free forms for some treatments, indicating that the conjugate forms should be considered for a comprehensive assessment of the threat posed by estrogens.

A systematic investigation to optimize simultaneous extraction and liquid chromatography tandem mass spectrometry analysis of estrogens and their conjugated metabolites in milk.

In this study, the simultaneous extraction of estrone (E1), 17beta-estradiol (E2), estriol (E3), ethinylestradiol (EE2), and their glucuronated and sulfated metabolites in milk was optimized using solid-phase extraction (SPE). The aim of this research was to analyze estrogens and their conjugated metabolites by liquid chromatography with tandem mass spectrometry (LC-MS/MS) in a single run, without the need to perform enzymatic cleavage and derivatization. Two SPE cartridges in tandem were used, consisting of sorbents based on the hydrophilic-lipophilic balance and amine-functionalized packing materials. To monitor analyte loss at every step of the SPE procedure (14)C-labeled E2 was spiked into the milk sample and the radioactivity was monitored at all stages of the SPE. In addition, non-radiolabeled standards of estrogens and metabolites were used to optimize solvent systems for the SPE and LC-MS/MS. The optimized method described in this paper can achieve recoveries ranging from 72% to 117% for the free estrogens (E1, E2, E3, and EE2), and 62% to 112% for seven conjugated metabolites. The three doubly conjugated, highly polar metabolites included in this study gave lower recoveries (< or = 43%) due to poor retention in SPE. Finally, commercial milk samples were analyzed for the presence of estrogens and their conjugated metabolites. Estrone (concentration range: 23-67 ng/L) was found to be the major free estrogen present in all milk samples. Estradiol was consistently observed in milk, but the concentrations were below the limit of detection (LOD of 10 ng/L), and no estriol and ethinylestradiol were detected. Several conjugated estrogen metabolites were identified, 17beta-estradiol-3-glucuronide (71-289 ng/L), estrone-3-sulfate (60-240 ng/L), 17beta-estradiol-3,17beta-sulfate (< LOD to 30 ng/L), and estrone-3-glucuronide (< LOQ of 25 ng/L). This method proved efficient in the simultaneous analysis of estrogens and their metabolites in milk.