Phase IIa cross-over study of propylene glycol-free melphalan (LGD-353) and alkeran in multiple myeloma autologous transplantation.

Propylene Glycol-Free melphalan HCL for Injection (PGF-Mel) is a new formulation that incorporates Captisol, a specially modified cyclodextrin, to improve melphalan stability. In this phase IIa, open-label, randomized, cross-over design bioequivalence study, the pharmacokinetics of PGF-Mel were compared with the marketed formulation of melphalan, or Alkeran. Patients received half of the total dose of melphalan in the form of Alkeran and the other half in the form of PGF-Mel in an alternating manner. The pharmacokinetic measures were determined using WinNonlin 6.2 and bioequivalence was assessed using log-transformed systemic exposure parameters. Twenty-four patients, 11 females and 13 males, were enrolled between 4 February 2010 and 16 May 2011 at The University of Kansas Medical Center and The University of Kansas Cancer Center. The median age of enrolled subjects was 58 years (range: 48-65). All patients achieved myeloablation 3 days post autologous graft followed by successful neutrophil engraftment with a median of 11 days after transplant. Pharmacokinetic analysis showed that PGF-Mel was bioequivalent with Alkeran and also revealed that maximum plasma concentration (Cmax) and area under the plasma concentration-time curve (AUC) were higher (~10%) after PGF-Mel administration. In conclusion, PGF-Mel is considered bioequivalent to Alkeran while also demonstrating a marginally higher systemic drug exposure.

Evaluation of a second derivative UV/visible spectroscopy technique for nitrate and total nitrogen analysis of wastewater samples.

A method for nitrate analysis based on second derivative UV/Visible spectroscopy was developed by Simal et al. (1985: Simal J., Lage M. A., and Iglesias I. (1985) Second derivative ultraviolet spectroscopy and sulfamic acid method for determination of nitrates in water. J. Assoc. Analyt. Chem. 68, 962-964) and Suzuki and Kuroda (1987: Suzuki, N. and Kuroda R. (1987) Direct simultaneous determination of nitrate and nitrite by ultraviolet second-derivative spectrophotometry. Analyst 112, 1077-1079), and later modified for the analysis of total nitrogen in aqueous samples of varying nitrate:organic nitrogen ratios (Crumpton et al., 1992: Crumption W. G., Isenhart T. M. and Mitchell P. D. (1992) Nitrate and organic N analyses with second-derivative spectroscopy. Limnol. Oceanogr. 37, 907-913). The procedure uses the second derivative of the absorption spectrum for nitrate (NO3-), which has a peak at approximately 224 nm that is proportional to the NO3- concentration. Samples for total N analysis are first oxidized to NO3- by persulfate digestion. The objectives of this study were to: (1) test the accuracy and precision of the second derivative method through the use of NIST-traceable wastewater check samples; (2) determine whether the second derivative method for nitrate analysis can be used for wastewater samples and whether the method compares favorably with other currently used nitrate analysis methods; and (3) use the method to analyze wastewater samples containing a range of nitrate and total nitrogen concentrations. Our results indicated that the method needed to be modified to include a longer digestion time (60 min) and dilution of samples prior to digestion (if needed). With the modified method, nitrogen recoveries were not significantly different (P > or = 0.05) from samples with known N concentrations. In addition, nitrate concentrations in constructed wetland and wastewater samples analyzed by both second derivative spectroscopy and ion chromatography were not significantly different. Total nitrogen concentrations in wastewater samples also compared favorably to the same samples analyzed by Kjeldahl digestion. The method is faster, simpler, requires smaller sample volumes, and generates less waste than many EPA-approved methods of N analysis, and may offer a suitable alternative to current methods for analysis of nitrate and total N in wastewater samples.