Gentamicin sulphate permeation through porcine intestinal epithelial cell monolayer

Gentamicin is an aminoglycoside antibiotic widely used in combination with dimethyl sulphoxide (DMSO) in topical drug formulations. It is not known, however, whether DMSO can enhance the permeation of gentamicin through biological membranes, leading to oto- and nephrotoxic side effects. A simple and reliable high-performance liquid chromatographic (HPLC) method was applied for the quantitative determination of gentamicin collected from the apical and basolateral compartments of the porcine intestinal epithelial cell line IPEC-J2 cell monolayer using fluorometric derivatisation of the analyte with fluorenylmethyloxycarbonyl chloride (FMOC) prior to chromatographic run in the presence and absence of 1% DMSO. The lack of change in transepithelial electrical resistance (TER) demonstrated that gentamicin and 1% DMSO did not affect IPEC-J2 cell monolayer integrity via the disruption of cell membranes. Chromatographic data also ascertained that gentamicin penetration across the cell monolayer even in the presence of 1% DMSO was negligible at 6 h after the beginning of apical gentamicin administration. This study further indicates that the addition of this organic solvent does not increase the incidence of toxic effects related to gentamicin permeation

Impact of water temperature and structural parameters on the hydraulic labyrinth-channel emitter performance

The effects of water temperature and structural parameters of a labyrinth emitter on drip irrigation hydraulic performance were investigated. The inside structural parameters of the trapezoidal labyrinth emitter include path width (W) and length (L), trapezoidal unit numbers (N), height (H), and spacing (S). Laboratory experiments were conducted using five different types of labyrinth-channel emitters (three non-pressure compensating and two pressurecompensating emitters) commonly used for subsurface drip irrigation systems. The water temperature effect on the hydraulic characteristics at various operating pressures was recorded and a comparison was made to identify the most effective structural parameter on emitter performance. The pressure compensating emitter flow exponent (x) average was 0.014, while non-pressure compensating emitter�s values average was 0.456, indicating that the sensitivity of nonpressure compensating emitters to pressure variation is an obvious characteristic (p < 0.001) of this type of emitters. The effects of water temperature on emitter flow rate were insignificant (p > 0.05) at various operating pressures, where the flow rate index values for emitters were around one. The effects of water temperature on manufacturer�s coefficient of variation (CV) values for all emitters were insignificant (p > 0.05). The CV values of the non-pressure compensating emitters were lower than those of pressure compensating emitters. This is typical for most compensating models because they are manufactured with more elements than non-compensating emitters are. The results of regression analysis indicate that N and H are the essential factors (p < 0.001) to affect the hydraulic performanc

Determination of the bioavailability of gentamicin to the lungs following inhalation from two jet nebulizers

NoAims To determine the bioavailability of gentamicin to the lung following inhalation from two jet nebulizers. Methods Serial urine samples were obtained from 10 volunteers after a 80 mg dose given orally, nebulized from a Pari LC + (PARI) and MicroNeb III (MN) devices, or after a 40 mg intravenous dose. In vitro aerodynamic characteristics of the nebulized doses were also determined. Results The mean (SD) absolute gentamicin lung bioavailalibility following delivery by PARI and MN devices was 1.4 (0.4) and 1.7 (0.5) %. The mass median aerodynamic diameter (MMAD) of the drug particles from the PARI and MN systems was 8.6 (0.6) and 6.7 (0.5) µm and the corresponding fine particle doses (FPD) were 10.2 (2.8) and 11.7 (1.5) mg. Conclusions The MMAD and FPD data reflect the poor lung deposition of gentamicin identified by urinary excretion