Yehia Badr

Abstract Five signal processing techniques were applied to ratio spectra for quantitative determination of bisoprolol (BIS) and hydrochlorothiazide (HCT) in their binary mixture. The proposed techniques are Numerical Differentiation of Ratio Spectra (ND-RS), Savitsky–Golay of Ratio Spectra (SG-RS), Continuous Wavelet Transform of Ratio Spectra (CWT-RS), Mean Centering of Ratio Spectra (MC-RS) and Discrete Fourier Transform of Ratio Spectra (DFT-RS). The linearity of the proposed methods was investigated in the range of 2–40 and 1–22 μg/mL for \{BIS\} and HCT, respectively. The proposed methods were applied successfully for the determination of the drugs in laboratory prepared mixtures and in commercial pharmaceutical preparations and standard deviation was less than 1.5. The five signal processing techniques were compared to each other and validated according to the İCH\} guidelines and accuracy, precision, repeatability and robustness were found to be within the acceptable limit.

Polycrystalline lithium-ammonium sulphate samples were subjected to X-ray diffraction analysis for determining the lattice parameters of the prepared mixed crystals. The compositions of the samples were determined using X-ray microanalysis. The Li0.5(NH4)0.5SO4 samples were irradiated with different doses of γ-radiation in order to investigate the effect of this ionizing radiation on the phase transition temperatures Tc1 and Tc2. The temperature dependence of the d.c. resistivity ρd.c. and dielectric constant ϵ of irradiated samples showed (i) a shift of Tc1 to higher temperatures; (ii) a shift of Tc2 to lower temperatures; and (iii) the appearance of a new anomaly near 128°C at moderately high γ-doses. The mechanisms giving rise to this behaviour are discussed.

Polycrystalline lithium-ammonium sulphate samples were subjected to X-ray diffraction analysis for determining the lattice parameters of the prepared mixed crystals. The compositions of the samples were determined using X-ray microanalysis. The Li0.5(NH4)0.5SO4 samples were irradiated with different doses of γ-radiation in order to investigate the effect of this ionizing radiation on the phase transition temperatures Tc1 and Tc2. The temperature dependence of the d.c. resistivity ρd.c. and dielectric constant ϵ of irradiated samples showed (i) a shift of Tc1 to higher temperatures; (ii) a shift of Tc2 to lower temperatures; and (iii) the appearance of a new anomaly near 128°C at moderately high γ-doses. The mechanisms giving rise to this behaviour are discussed.

Abstract Cyproheptadine hydrochloride (CYP HCl) {4-(5H-dibenzo[a,d]-cyclohepten-5-ylidene)-1-methylpiperidine hydrochloride} is a first-generation antihistamine with additional anticholinergic, antiserotonergic, and local-anesthetic properties. The geometry optimization, Mulliken atomic charges and wavenumber and intensity of the vibrational bands of all of the possible modes of \{CYP\} \{HCl\} have been calculated using ab initio Hartree–Fock (HF) and density functional theory (DFT) employing the \{B3LYP\} functional with the 6-311G(d,p) basis set. We have compared the calculated İR\} and Raman wavenumbers with experimental data. Quantum-chemical calculations of the geometrical structure, energies, and molecular electrostatic potential and \{NBO\} analysis of \{CYP\} \{HCl\} have been performed using the B3LYP/6-311G(d,p) method. The electric dipole moment (μ), static polarizability (α) and the first hyperpolarizability (β) values of the title compound have been computed using \{HF\} and \{DFT\} methods. The study reveals that the antihistaminic pharmacological property of \{CYP\} \{HCl\} has a large β value and, hence, may in general have potential applications in the development of non-linear optical materials. The experimental and calculated results for \{CYP\} \{HCl\} have also been compared with those for mianserin HCl.