Development and validation of HPLC method with fluorometric detection for quantification of bisnaphthalimidopropyldiaminooctane in animal tissues following administration in polymeric nanoparticles.

A simple, sensitive and specific high-performance liquid chromatography method for the quantification of bisnaphthalimidopropyldiaminooctane (BNIPDaoct), a potent anti-Leishmania compound, incorporated into poly(d,l-lactide-co-glycolic acid) (PLGA) nanoparticles was developed and validated toward bioanalysis application. Biological tissue extracts were injected into a reversed-phase monolithic column coupled to a fluorimetric detector (λexc = 234 nm, λem = 394 nm), using isocratic elution with aqueous buffer (acetic acid/acetate 0.10 M, pH 4.5, 0.010 M octanesulfonic acid) and acetonitrile, 60:40 (v/v) at a flow rate of 1.5 mL min-1. The run time was 6 min, with a BNIPDaoct retention time of 3.3 min. Calibration curves were linear for BNIPDaoct concentrations ranging from 0.002 to 0.100 μM. Matrix effects were observed and calibration curves were performed using the different organ (spleen, liver, kidney, heart and lung) extracts. The method was found to be specific, accurate (97.3-106.8% of nominal values) and precise for intra-day (RSD 88.4%. The LOD and LOQ for biological matrices were ≤0.8 and ≤1.8 nM, respectively, corresponding to values ≤4 and ≤9 nmol g-1 in mice organs. The method developed was successfully applied to biodistribution assessment following intravenous administration of BNIPDaoct in solution or incorporated in PLGA nanoparticles

Spectroscopy studies of 4H-SiC

Calculations of the total dielectric functions and the optical bandgap energy (OBGE) of 4HSiC were performed by the full-potential linear muffin-tin-orbital method. The results are compared to spectroscopic ellipsometry dielectric measurements agreeing closely over in a wide range of energies. The obtained theoretical value of the (OBGE) agrees very closely with the measured ones obtained by transmission and photoacoustic spectroscopies at room temperature performed on 470 µm thick wafer and a 25 µm thick homoepitaxial layer of 4H-SiC samples grown (n-type, Siface) by hot wall CVD