Indoor PM2.5 removal efficiency of two different non-thermal plasma systems.

The use of non-thermal plasma (NTP) generators in air processing systems and their duct networks to improve indoor air quality (IAQ) has grown considerably in recent years. This paper reviews the advantages and disadvantages of NTP generators for IAQ improvement in biological, chemical and particulate pollutant terms. Also, it assesses and compares the ability of a multipin corona discharge (MPCD) and a dielectric barrier discharge (DBD) generator to reduce the concentration of fine particulate matter (PM2.5) in recycled, unfiltered air in a refrigeration chamber. The MPCD generator was found to have a higher PM2.5 removal efficiency; also, it was faster in removing pollutants, used less energy, and produced much less ozone. The fact that the MPCD generator performed better was seemingly the result of its increased ion production mainly. NTP generators, however, cannot match air filtration media purifiers in this respect as the latter are much more effective in removing particles. Besides, NTP-based air purifying technology continues to be subject to a major drawback, namely: the formation of ozone as a by-product. In any case, the ozone generation was uncorrelated to ion emission when using different technologies.

Evaluation of the quality of four Mexican drug products containing sodium naproxen.

BACKGROUND: There is currently a lot of concern about the quality and therapeutic effectiveness of Mexican pharmaceutical products, and considerable price differences between alternative products containing the same active principle. OBJECTIVE: To establish whether four Mexican drug products, a high price and three lower-cost branded drug products containing sodium naproxen (550 mg immediate release tablets) have equivalent, and consistent pharmaceutical qualities. METHODS: The four products were acquired in Mexico city. Assay for sodium naproxen, content uniformity, disintegration time and dissolution tests were performed according to USP procedures. Drug dissolution profiles were compared using a similarity factor (f(2)). RESULTS AND DISCUSSION: All of the tested products met pharmacopeial quality standards with respect to their active pharmaceutical content and a released drug percentage >70% in 45 min. Lot-to-lot lack of similarity between drug dissolution profiles was observed for two of the products tested. CONCLUSION: There was no significant differences in the quality of the pharmaceutical products tested when judged by the USP pharmaceutical quality standards. However, some differences were observed in the dissolution profiles of the brands tested. Whether these differences are clinically meaningful requires in vivo bioequivalence studies.