Solid dispersion (SD) formulation has attracted much attention due to its potential in enhancing dissolution performances of poorly soluble active pharmaceutical ingredients (API). Recently, a review on dissolution performances of SDs classifies the improvement into 3 categories, where 82 % of the studies showed improved bioavailability, 8 % showed reduced bioavailability and 10 % revealed similar bioavailability as compared to pure APIs. This indicates the inconsistent degrees of dissolution improvement of poorly soluble APIs in SD. Although a few factors related to the choice of carriers have been suggested to contribute to the dissolution improvement, however, the underlying factor determining the discrepancy in the degree of dissolution improvement remains in vague. It is hypothesized that the API contributes to the degree of dissolution improvement of SD. Hence, the factor of amorphous solubility advantage of API which leads to the different degrees of dissolution enhancement of SD is investigated in this research. Polyvinylpyrrolidone vinyl acetate (PVPVA)-based SD is prepared with three poorly soluble APIs. Physicochemical properties of SD were characterized using infrared spectroscopy, differential scanning calorimetry (DSC) and X-ray powder diffraction. The dissolution efficiency of each SD was calculated and compared to physical mixture and pure API. Theoretical amorphous solubility advantage for each API was calculated using the thermal properties obtained from DSC. The calculated values were found to be correlating well with the dissolution enhancement of the respective SDs. Hence, this theoretical approach can be utilized as an initial screening tool of API candidates in SD formulation during early pharmaceutical development.
This work represents the preparation of the starting material, 3-chloro-2-oxo-1,4-dithiacyclohexane (S) using a new method. This material was reacted with, 4-phenylthiosemicarbazide to give (H3NS3) as a tetradentate ligand H3L. New complex of rhenium (V) with this ligand of the formula [ReO(L)] was prepared. New complexes of the general formula [M(HL)] of this ligand when reacted with some metal ions where: M = Ni(II), Cu(II), Cd(II), Zn(II), Hg(II) have been reported. The ligand and the complexes were characterized by infrared, ultraviolet–visible, mass, 1H nuclear magnetic resonance and atomic absorption spectroscopic techniques and by (HPLC), elemental analysis, and electrical conductivity. The proposed structure for H3L with Re (V) i
... Show MoreThe complexes of the 2-hydroxy-4-Nitro phenyl piperonalidene with metal ions Cr(III), Ni(II), Pt(IV) and Zn(II) were prepared in ethanolic solution. These complexes were characterized by spectroscopic methods, conductivity, metal analyses and magnetic moment measurements. The nature of the complexes formed in ethanolic solution was study following the molar ratio method. From the spectral studies, monomer structures proposed for the nickel (II) and Zinc (II) complexes while dimeric structures for the chromium (III) and platinum (IV) were proposed. Octahedral geometry was suggested for all prepared complexes except zinc (II) has tetrahedral geometry, Structural geometries of these compounds were also suggested in gas phase by using
... Show MoreThe compound [L] was produced in the current study through the reaction of 4-aminoacetophenon with 4-methoxyaniline in the cold, concentrated HCl with 10% NaNO2. Curcumin, several transition metal complexes (Ni (II), La (III), and Hg (II)), and compound [L] were combined in EtOH to create new complexes. UV-vis spectroscopy, FTIR, AA, TGA-DSC, conductivity, chloride content, and elemental analysis (CHNS) were used to describe the structure of produced complexes. Biological activities against fungi, S. aureus (G+), Pseudomonas (G-), E. coli (G-), and Proteus (G-) were demonstrated using complexes. Depending on the outcomes of the aforementioned methods, octahedral formulas were given as the geometrical structures for each created comp
... Show MoreLimitations of the conventional diagnostic techniques urged researchers to seek novel methods to predict, diagnose, and monitor periodontal disease. Use of the biomarkers available in oral fluids could be a revolutionary surrogate for the manual probing/diagnostic radiograph. Several salivary biomarkers have the potential to accurately discriminate periodontal health and disease. This study aimed to determine the diagnostic sensitivity and specificity of salivary interleukin (IL)‐17, receptor activator of nuclear factor‐κB ligand (RANKL), osteoprotegerin (OPG), RANKL/OPG for differentiating (1) periodontal health from disease and (2) stable a
5-((2,4-dibromo-6-((cyclohexyl(methyl)amino)methyl)phenyl)diazenyl)quinolin-8-ol azo ligand (L) has been synthesized through the reaction of diazonium salt for 2,4-dibromo-6-((cyclohexyl(methyl)amino)methyl)aniline with 8-hydroxyquinoline. The azo ligand (L) was characterized utilizing spectroscopic techniques, including FTIR, UV-Vis, 1H and 13C NMR, as well as mass spectrometry and micro-elemental analysis (C.H.N). Metal complexes containing Co(II), Ni(II), Cu(II), and Zn(II) were synthesized and analyzed through mass spectrometry, flame atomic absorption, elemental analysis (C.H.N), infrared and UV-Vis spectroscopy, along with measurements of conductivity and magnetic properties. The experimental findings suggested that all met
... Show MoreThe ligand 4-(2-aminmo-5-nitro-phenylazo)-1,5-dimethyl-2-phenyl-1,2-dihydro-pyrazol-3-one derived from 4-aminoantipyrine and 4-nitroaniline was synthesized. The synthesized ligand was characterized by 1HNMR, FT-IR, UV-Vis spectra and (C.H.N) analysis. Complexes of (YIII and LaIII ) with the ligand were prepared in aqueous ethanol with a 1:2 M:L ratio and at optimum pH. The prepared complexes were characterized by using flame atomic absorption, FT-IR, UV-Vis spectra,(C.H.N) analysis and conductivity measurement. The stoichiometry of complexes was studied by the mole ratio and job methods. A concentration range (1×10-4 - 3×10-4 M) obeyed Beer's law, the complex solutions show high values of molar absorption. On the basis of physicochemical
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