Evaluation of the Nano Spray Dryer B-90 for pharmaceutical applications.

The vibrating mesh spray technology implemented in the Nano Spray Dryer B-90 was evaluated for pharmaceutical applications by spray drying common pharmaceutical excipients (e.g. trehalose, mannitol) and model drugs (e.g. griseofulvin). Aerosol droplet size measurements investigated the influence of spray solution factors (e.g. viscosity, surface tension) and of vibrating mesh aperture sizes on particle characteristics. Particle deposition on the spray nozzle was addressed by analyzing the influence of spray solute concentration and solvent on the process outcome. Submicron particles with 0.5 ?m and 0.8 ?m mean particle size were obtained at high yields for 50?mg powder amounts.

Influence of bulk and tapped density on the determination of the thermal conductivity of powders and blends.

The aim of this study was to evaluate a non-steady-state needle sensor to determine the thermal conductivity (lambda) of powders and their blends. It was investigated how lambda of different powders was influenced by (1) bulk vs tapped density, (2) moisture content of the powders, and (3) blending time of the powders. Different powders were evaluated: 2 lactose powders with different properties, a microcrystalline cellulose powder, a cornstarch powder, and 3 herbal extracts. The results show that the values of lambda are highly dependent on the bulk and tapped density of the powders. Bulk density measurements were generally not sensitive enough to detect the moisture content within a powder. The tapped density measurements were reliable and highly reproducible and could differentiate between the nature of a powder and the powder moisture content. Measurements of lambda were able to be used to monitor the powder blending process. To be able to use thermal conductivity measurements to characterize powder properties in quality control, the powder density must be defined because changes in density affect lambda. Using thermal conductivity as a measure for process analytical technology seems to be feasible and can add valuable information to the process under investigation.

Performance of a Western immunoblot assay to detect specific anti-Toxoplasma gondii IgG antibodies in human saliva.

Toxoplasma gondii represents the most prominent infectious parasitic organism found in humans. While normally asymptomatic in healthy individuals, toxoplasmosis can cause abortion in patients during pregnancy, or can be fatal in immunosupressed individuals such as persons suffering from acquired immunodeficiency syndrom (AIDS). Toxoplasma gondii infection in humans is routinely assesssed by serological means. Here, we show that detection of anti-T. gondii IgG is also possible using a non-invasive methodology employing saliva. Sera and saliva of 201 healthy volunteers were investigated for the presence of anti-T. gondii-IgG antibodies by immunoblotting. The sera of 59 (29.4%) individuals showed IgG antibodies against T. gondii by ELISA, Vidas, and immunoblotting; 58 (98.3%) of these were also positive for anti-T. gondii IgG in the saliva immunoblot, with diagnostic relevant bands of Mr of 32-35 kDa and 40-45 kDa. The saliva immunoblot test exhibits a specificity of 100% and a sensitivity of 98.5%. Thus, saliva could be used as an alternative, non-invasive means for the detection of specific anti-T. gondii IgG in humans.

Effect of a fixed dorzolamide-timolol combination on intraocular pressure after small-incision cataract surgery with Viscoat.

PURPOSE: To evaluate the effect of a fixed dorzolamide-timolol combination (Cosopt) on intraocular pressure (IOP) after small-incision cataract surgery with sodium chondroitin sulfate 4%-sodium hyaluronate 3% (Viscoat). SETTING: Department of Ophthalmology, University of Vienna, Vienna, Austria. METHODS: This prospective randomized study comprised 76 eyes of 38 patients scheduled for small-incision cataract surgery in both eyes. Patients were randomized to receive 1 drop of the fixed dorzolamide-timolol combination in 1 eye or no treatment (control) immediately after cataract surgery. The fellow eye received the other assigned treatment. Cataract surgery was performed with Viscoat in an identical fashion in both eyes. The IOP was measured preoperatively and 6 hours, 20 to 24 hours, and 1 week postoperatively. RESULTS: Six hours after surgery, the mean increase in IOP was significantly lower in the dorzolamide-timolol group than in the control group (4.3 mm Hg +/- 5.6 [SD] versus 8.4 +/- 6.1 mm Hg; P =.003). Two eyes in the dorzolamide-timolol group and 9 in the control group had IOP spikes of 30 mm Hg or higher (P =.022). Twenty to 24 hours after surgery, the mean IOP change was -2.6 +/- 3.3 mm Hg in the dorzolamide-timolol group and 1.5 +/- 3.2 mm Hg in the control group (P<.001). CONCLUSIONS: The fixed dorzolamide-timolol combination was effective in reducing IOP 6 hours and 20 to 24 hours after cataract surgery. However, it did not prevent Viscoat-induced IOP spikes of 30 mm Hg or higher.