Novel Ratio Subtraction and Isoabsorptive Point Methods for Determination of Ambroxol Hydrochloride and Doxycycline in their Combined Dosage Form: Development and Validation

Purpose: To develop and validate two innovative spectrophotometric methods used for the simultaneous determination of ambroxol hydrochloride and doxycycline in their binary mixture.Methods: Ratio subtraction and isoabsorptive point methods were used for the simultaneous determination of ambroxol hydrochloride and doxycycline in their binary mixture. Linear correlations were obtained in the concentration range of 6 - 40 and 4 - 32 μg mL-1 for ambroxol hydrochloride and doxycycline, respectively. Ratio subtraction method was utilized for determination of ambroxol hydrochloride at 246.5 nm while isoabsorptive point method was employed for doxycycline at 244 nm (using methanol as a solvent) in mixtures as well as in their combined dosage form (Ambrodoxy capsules).Results: The proposed methods were successfully applied to the analysis of the pharmaceutical capsules containing the two analytes. Recovery for ambroxol hydrochloride and doxycycline in capsules was 99.49 and 99.96 %, respectively. The relative standard deviation (% RSD) for the assay of the capsules was < 1 %. Validation of the two methods was assessed according to International Council on Harmonization (ICH) guidelines regarding linearity, accuracy, precision, specificity and range. The results of the proposed methods compared favorably with those obtained by a reported chemometricsassisted ultraviolet (UV)-spectroscopic method.Conclusion: The proposed methods are rapid, selective, simple and accurate. They also represent suitable alternatives to the chromatographic methods currently used for the analysis of the pharmaceutical mixtures in various dosage forms.Keywords: Ambroxol, Doxycycline, Ratio subtraction method, Isoabsorptive point method, Binary mixture, Spectrophotometr

Detection of hexavalent uranium with inline and field-portable immunosensors

An antibody that recognizes a chelated form of hexavalent uranium was used in the development of two different immunosensors for uranium detection. Specifically, these sensors were utilized for the analysis of groundwater samples collected during a 2007 field study of in situ bioremediation in a aquifer located at Rifle, CO. The antibody-based sensors provided data comparable to that obtained using Kinetic Phosphorescence Analysis (KPA). Thus, these novel instruments and associated reagents should provide field researchers and resource managers with valuable new tools for on-site data acquisition

Constraints on the χ_(c1) versus χ_(c2) polarizations in proton-proton collisions at √s = 8 TeV

The polarizations of promptly produced χ_(c1) and χ_(c2) mesons are studied using data collected by the CMS experiment at the LHC, in proton-proton collisions at √s=8  TeV. The χ_c states are reconstructed via their radiative decays χ_c → J/ψγ, with the photons being measured through conversions to e⁺e⁻, which allows the two states to be well resolved. The polarizations are measured in the helicity frame, through the analysis of the χ_(c2) to χ_(c1) yield ratio as a function of the polar or azimuthal angle of the positive muon emitted in the J/ψ → μ⁺μ⁻ decay, in three bins of J/ψ transverse momentum. While no differences are seen between the two states in terms of azimuthal decay angle distributions, they are observed to have significantly different polar anisotropies. The measurement favors a scenario where at least one of the two states is strongly polarized along the helicity quantization axis, in agreement with nonrelativistic quantum chromodynamics predictions. This is the first measurement of significantly polarized quarkonia produced at high transverse momentum