A simple, sensitive and reproducible reversed phase ultra performance liquid chromatography (RP-UPLC) coupled with a photodiode array detector method was developed for the quantitative determination of metaxalone (META) in pharmaceutical dosage forms. The method is applicable to the quantification of related substances and assay of drug product. Chromatographic separation was achieved on an Acq...

A simple, sensitive, and reproducible reversed-phase high-performance liquid chromatography (RP-HPLC) method, coupled with a photodiode array detector, was developed for the determination of rupatadine (RUPA) and its related substances in pharmaceutical dosage forms. Chromatographic separation was achieved on the Hypersil BDS (150 x 4.6 mm, 5 μm) column with a mobile phase containing a gradient...

A gradient, reversed-phase liquid chromatographic (RP-LC) method was developed for the quantitative determination of Norethindrone in Norethindrone tablets, used to treat drug for contraception and hormone replacement therapy. The gradient LC method employs solutions A and B as mobile phase. The solution A contains a mixture Milli Q water, acetonitrile and tetrahydrofuran in the ratio of 40:30:...

To date, no report was concerned with participation of reactive oxygen species in waters during photolysis of low-brominated diphenyl ethers (LBDEs). Herein, we found that electron spin resonance (ESR) signals rapidly increased with increasing irradiation time in the solution of LBDEs and 4-oxo-TMP solutions. But this phenomenon did not occur in the presence of NaN3 (1O2 quencher) demonstrating...

The nitramine-containing explosive RDX and the nitroester-containing explosive PETN are shown to be susceptible to photofragmentation upon exposure to sunlight. Model compounds containing nitroester and nitramine moieties are also shown to fragment upon exposure to UV irradiation. The products of this photofragmentation are reactive, electrophilic NO(x) species, such as nitrous and nitric acid,...

To clarify the formation process of acid metarhodopsin in the cephalopod rhodopsin cycle, changes in the difference spectrum of squid (Todarodes pacificus) rhodopsin in acid (pH 5.7, or pH 6.1) and alkaline (pH 10.2) solutions were studied at various temperatures by applying the flash photolytic technique. An intermediate with an absorption maximum at about 475 nm was transformed from lumirhodo...

Two-photon laser-induced fluorescence (TPLIF) is a well-recognized approach for detecting atomic oxygen however, measurements to date have been restricted to a single point within a flow, flame, or plasma, due to the inherently high intensity requirements for the excitation laser. Furthermore, the high-intensity ultraviolet (UV) photons used for two-photon excitation process can photochemically...