Improved Biosafety and Transdermal Delivery of Aconitine via Diethylene Glycol Monoethyl Ether-Mediated Microemulsion Assisted with Microneedles

In the current study, diethylene glycol monoethyl ether-mediated microemulsions were combined with microneedles for enhanced transdermal aconitine delivery. The oil-in-water microemulsion increasedaconitine solubility and enhanced transdermal drug delivery and assistance with metal microneedles enhanced permeation of the aconitine-loaded microemulsion. Carried by the microemulsion, the in vitro permeability of aconitine was significantly enhanced, and further improved using microneedles. In vivo microdialysis revealed that the subcutaneous local drug concentration reached a high level within 30 min and remained relatively consistent to the end of the experimental period. AUC0-t of the microemulsion group was significantly higher than that of the aqueous solution group, and the microemulsion combined with microneedles group achieved the highest AUC0-t among the tested groups. The microemulsion and microdialysis probe also showed good biocompatibility with skin tissue. The microemulsion could be internalized by HaCaT and CCC-ESF-1 cells via lysosomes. The in vitro cytotoxicity of aconitine toward skin cells was reduced via encapsulation by microemulsion, and the prepared microemulsion developed no skin irritation. Hence, transdermal aconitine delivery and drug biosafety were effectively improved by loading into the microemulsion and assisting with microneedles, and in vivo microdialysis technique is suitable for realtime monitoring of transdermal drug delivery with microemulsion-based drug vehicles.

Effect of Some Oxygenates on the Opacity Level of a DI Diesel Engine with and without DPF

Toyota car fitted with smoke meter to measure the opacity in the exhaust was used. Five different types of oxygenates were used with the concentration of each one varied between 5 to 20% by volume at an increment of 5%. The results show a significant reduction in the opacity of the exhaust products. A maximum of 70% reduction was achieved when 15% ethanol was added at 3000 RPM, and 62% reduction when 20% methanol was added at same speed. As for Dimethoxy Ethane (DMET), a maximum reduction of 30% was achieved at 3000 RPM and that of Tri-propylene glycol methyl ether (TPGME) was 27.3% at same speed. Diethylene glycol monoethyl ether (DGME) did not show encouraging results as a maximum reduction of 10.3% was achieved at 2000 RPM with 5% of DGME. Further, it was found that the reduction in the opacity level was less significant when the filter was used. This, perhaps, is due to the nature of the DPF used.