Pharmacokinetics and bioequivalence study of a generic amlodipine tablet formulation in healthy male volunteers.

Two different tablets containing amlodipine besylate (CAS 111470-99-6) (Vazkor 10 mg tablet as test preparation and 10 mg tablet of the originator product as reference preparation) were investigated in 18 healthy male volunteers in order to compare the bioavailability and prove the bioequivalence between both treatments after oral single dose administration. The study was performed according to an open-label, randomized, two-period cross-over design with a wash-out phase of 21 days. Blood samples for pharmacokinetic profiling were taken up to 144 h post-dose, and amlodipine plasma concentrations were determined with a validated LC-MS/MS method.

Bioequivalence study of sultamicillin suspensions.

Sultamicillin (CAS 76497-13-7) is a prodrug combination of ampicillin (CAS 69-53-4) and sulbactam (CAS 68373-14-8), with the antibiotic ampicillin and the beta-lactamase inhibitor sulbactam chemically linked as double ester. The present study was performed to investigate the relative bioavailability and to assess the bioequivalence of two different sultamicillin suspensions (Devasid 250 mg/5 ml as test preparation and 375 mg/7.5 ml of the originator product as reference preparation).

Comparative pharmacokinetics of two tablet formulations of amoxicillin: bioequivalence assessment.

The aim of the present study was to compare the bioavailability of amoxicillin (CAS 26787-78-0) from two different amoxicillin tablets (Demoksil 1 g tablet as test preparation and 1 g tablet of the originator product as reference preparation). The study was conducted according to an open-label, randomised two-period cross-over design with a wash-out phase of 4-7 days. Blood samples for pharmacokinetic profiling were taken up to 10 h post-dose, and amoxicillin plasma concentrations were determined with a validated LC-MS/ MS method.

Relation between intracellular location and photodynamic efficacy of 5-aminolevulinic acid-induced protoporphyrin IX in vitro. Comparison between human glioblastoma cells and other cancer cell lines.

A promising clinical application of 5-aminolevulinic acid (5-ALA)-induced protoporphyrin IX (PP IX) is fluorescence detection and photodynamic treatment of residual tumour tissue during surgical resection of high grade malignant glioma. U373 MG human glioblastoma cells were used as a model system to study the relation between intracellular location and photodynamic efficacy of 5-ALA-induced PP IX in more detail. Therefore, ultra-sensitive fluorescence microscopy, using either optical excitation of whole cells or selective excitation of the plasma membrane by an evanescent electromagnetic field, was combined with quantitative measurements of intracellular porphyrin amount and phototoxicity.

Total internal reflectance fluorescence reader for selective investigations of cell membranes.

A novel setup for fluorescence measurements of surfaces of biological samples, in particular the plasma membrane of living cells, is described. The method is based on splitting of a laser beam and multiple total internal reflections (TIR) within the bottom of a microtiter plate (cell substrate), such that up to 96 individual samples are illuminated simultaneously by an evanescent electromagnetic field. Main prerequisites are an appropriate thickness and a high transmission of the glass bottom, which is attached to the 96-well cell culture plate by a noncytotoxic adhesive.

Autofluorescence lifetime imaging of cultivated cells using a UV picosecond laser diode.

Lifetime images of autofluorescence of cultivated endothelial cells were recorded using a novel picosecond laser diode in the near ultraviolet range (375 nm). In contrast to existing picosecond light sources this wavelength permits efficient excitation of the free and protein bound coenzyme NADH with fluorescence lifetimes of 0.4-0.

Laser-assisted fluorescence microscopy for measuring cell membrane dynamics.

Membranes of living cells are characterized by laser-assisted fluorescence microscopy, in particular a combination of microspectrofluorometry, total internal reflection fluorescence microscopy (TIRFM), fluorescence lifetime imaging (FLIM) and Forster resonance energy transfer (FRET) spectroscopy. The generalized polarization (GP, characterizing a spectral shift which depends on the phase of membrane lipids) as well as the effective fluorescence lifetime (tau(eff)) of the membrane marker laurdan were revealed to be appropriate parameters for membrane stiffness and fluidity. GP decreased with temperature, but increased during cell growth and was always higher for the plasma membrane than for intracellular membranes.

A novel, high-affinity, fluorescent progesterone receptor antagonist. Synthesis and in vitro studies.

The present paper describes the chemical synthesis and in vitro characterization of a novel, high-affinity, fluorescent progesterone receptor (PR) antagonist. The three-step synthesis was carried out starting from mifepristone. After demethylation with calcium oxide, the methylamino group was alkylated with 6-bromohexanol, and the resulting compound was reacted with fluorescein 5-isothiocyanate, yielding the fluorescein-mifepristone conjugate.

Fluorescence lifetime imaging (FLIM) of rhodamine 123 in living cells.

A novel setup for fluorescence intensity and lifetime imaging (FLIM) of living cells is reported. Time-resolving techniques are combined with total internal reflection fluorescence microscopy (TIRFM), which permits optical excitation of either plasma membranes or whole cells depending on whether the angle of incidence of the excitation light is greater or smaller than the critical angle for total internal reflection. The method is applied to BKEz-7 endothelial cells incubated with various concentrations of the well established mitochondrial marker rhodamine 123(R123).

Laser-assisted optoporation of single cells.

The plasma membrane of Chinese hamster ovary cells was made permeable using the focused beam of an argon ion laser (488 nm) and phenol red as a light absorbing dye. Small circular dark spots on the cell surface appeared immediately after laser irradiation and disappeared within about 5 min. They were related to transient changes in membrane properties, which could be visualized using the fluorescent marker laurdan, and were probably due to a local increase in temperature.