An in vitro controlled release study of valproic acid encapsulated in a titania ceramic matrix

Despite the therapeutic efficacy of valproic acid towards numerous diseases, its poor bioavailability and systemic side effects pose significant barriers to long term treatment. In order to take advantage of controlled release implants of valproic acid, the drug was encapsulated into titania ceramic matrices via a sol-gel process. The integrity and structure of valproic acid-containing matrices were characterized through the use of FESEM, TEM, and BET analyses. In vitro controlled release studies and kinetic analyses were performed under ambient conditions (25 °C, atmospheric pressure) and controlled release behaviors were studied using a GC-MS method. Results showed first order dependence in the rate of valproic acid release as a function of drug concentrations in the titania ceramic device. A marked dependence on the surface area and pore size distribution with drug loading was also observed. This research opens new possibilities for the design of novel time-delayed controlled release systems for valproic acid encapsulates.     

Mikrochemie

Ohne Zusammenfassung     

Recent advances in laser-based diagnostics for gaseous flows

Laser-based diagnostic techniques offer unique capabilities for experimentation on gaseous flows. In this paper, we overview recent progress of two concepts: spectrally resolved absorption and planar laser-induced fluorescence (PLIF) imaging. The absorption measurements utilize tunable diode lasers (TDLs) as light sources. Recent TDL applications include a wavelength-multiplexed system for rapid temperature sensing for use in combustion control, and absorption probes for time-resolved measurements of temperature, velocity and species concentrations in a hypersonic shock tunnel. Recent PLIF work includes applications to supersonic, exothermic flowfields relevant to ram accelerators, and development of a method for imaging temperature in air flows using acetone seeding.