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1.
ACS Biomater Sci Eng ; 2(12): 2139-2152, 2016 Dec 12.
Artículo en Inglés | MEDLINE | ID: mdl-33465890

RESUMEN

Engineering cobalt ferrites for application in health and biomedical science poses a challenge in terms of nanoscale morphology with a controlled size, shape, and thermochemical stability coupled with controlled properties for biocompatibility. Here, we report a simple one-step, low temperature approach to produce crystalline, nanosized cobalt ferrites (CFO) with a size ∼4.7 nm and demonstrate their applicability in breast cancer treatment. Inherent physiochemical and magnetic properties, which are quite important for biomedical applications, along with cytotoxicity of CFO nanoparticles (NPs) are investigated in detail. X-ray diffraction analyses confirm the cubic spinel phase with the tensile strain in crystalline CFO NPs. Chemical bonding analyses using infrared and Raman spectroscopic studies also support the cubic spinel phase. Electron microscopy and small-angle X-ray scattering revealed the narrow particle-size distribution and spherical-shape morphology. The as-synthesized CFO NPs exhibit superparamagnetic character. Unsaturated magnetization behavior suggests the existence of disordered spins in the surface layers. The temperature dependence of the magnetic parameters, namely, saturation magnetization, coercivity, retentivity, and squareness ratio, also supports the surface-localized spins. Cytotoxic activity of the as-synthesized CFO NPs against the human breast cancer (MCF-7) cell line and normal human peripheral blood mononuclear cells (PBMC) has been evaluated. The mild response of CFO NPs in terms of their antiproliferative nature against cancer cells and negligible Cytotoxicity reflecting their human-safe-and-friendly nature makes them suitable for bioapplications. Moreover, assessment of toxicity toward human red blood cells (RBC) revealed (<3%) hemolysis as compared to the positive control, suggesting potential applications of CFO NPs for human cells.

2.
Anc Sci Life ; 25(3-4): 57-63, 2006 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-22557208

RESUMEN

Metals and minerals are used profusely in practice of Ayurveda after proper incineration by the name of Bhasma. Some metals and minerals have the potency to produce toxic effects in human being. In this paper safety and toxicity profiles of Tamra Bhasma (incinerated copper, Cu), Lauha Bhasma (incinerated iron, Fe), and Yashada Bhasma (incinerated Zinc, Zn) has been presented, which reveal no serious deleterious effects on body function as a whole.

3.
Eur J Pharm Biopharm ; 61(3): 158-70, 2005 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-16005194

RESUMEN

In this work the Hammett acidity function has been measured to assess the relative acidity of excipients used in the preparation of pharmaceutical solid dosage forms. A systematic series of experiments is reported which illustrates how the selection of the measurement conditions can influence the results of such determinations. Although the technique is somewhat empirical and relies on several key assumptions it is shown that very consistent results can be achieved by carefully controlling the measurement conditions. It is also shown that by taking this approach laboratory-to-laboratory variation can be reduced to a negligible level and the influences of subtle changes in the acidity of pharmaceutical excipients due to intrinsic variations in their physical properties or due to different processing histories can be detected and quantified.


Asunto(s)
Excipientes/química , Calibración , Química Farmacéutica , Concentración de Iones de Hidrógeno , Lubrificación
4.
Int J Pharm ; 271(1-2): 95-113, 2004 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-15129977

RESUMEN

Vesicles with biological activity or with a targeting function in addition to carrier properties will have an added advantage. Vesicles prepared with amphiphiles having antioxidant property may have potential applications towards disorders implicated with reactive oxygen species. Ascorbyl palmitate (ASP) was explored as bilayer vesicle forming material. It formed vesicles (Aspasomes) in combination with cholesterol and a negatively charged lipid (dicetyl phosphate). Aspasomes were prepared by film hydration method followed by sonication in which aqueous azidothymidine (AZT) solution was encapsulated in aqueous regions of bilayer. Aspasomes were obtained with all compositions containing 18-72 mol% cholesterol. Differential scanning calorimetric data of aspasome dispersion and anhydrous mixtures of ascorbyl palmitate, cholesterol and dicetyl phosphate confirm the formation of bilayered vesicles with ascorbyl palmitate. Cholesterol content in aspasome did not exhibit any relation with vesicle size, zeta potential or percent entrapment. A substantial change in release rate of azidothymidine from aspasome was noticed on varying the proportion of cholesterol. Release rate and cholesterol content in Aspasomes did not exhibit any relation. A preparation with 45 mol% of cholesterol showed maximum retardation in release rate, than other compositions. The change in capture volume with time (latency) was studied for 8 h and with such a short duration study it was difficult to predict long term stability of these vesicles. But release experiments do indicate stability up to 18 h. Percent reducing activity of aspasome was estimated by measuring the absorbance of alpha,alpha-diphenyl-beta-picrylhydrazyl (DPPH) at 517 nm after addition of test antioxidant samples. These studies revealed that the antioxidant potency of ascorbyl moiety is retained even after converting ascorbyl palmitate into vesicles (Aspasomes). The antioxidant potency of Aspasomes was assessed by measuring the protection offered by this preparation against quinolinic acid induced lipoperoxidation of whole human blood in vitro, where in the lipoperoxidation was monitored by measuring thiobarbituric acid reactive substances (TBARS) levels. Aspasome rendered much better antioxidant activity than ascorbic acid. Transdermal permeation of aspasomal AZT, ASP-AZT aqueous dispersion and AZT-solution across excised rat skin was investigated in vitro using Franz diffusion cell. Permeation of aspasomal AZT was much higher than the other two preparations. However, ASP-AZT aqueous dispersion has also enhanced permeation of AZT significantly over the AZT-solution, indicating skin permeation enhancing property of ascorbyl palmitate.


Asunto(s)
Ácido Ascórbico/análogos & derivados , Ácido Ascórbico/química , Portadores de Fármacos/química , Animales , Antioxidantes/administración & dosificación , Antioxidantes/química , Antioxidantes/farmacocinética , Rastreo Diferencial de Calorimetría , Química Farmacéutica , Colesterol/química , Estabilidad de Medicamentos , Técnicas In Vitro , Membrana Dobles de Lípidos/química , Peroxidación de Lípido , Organofosfatos/química , Tamaño de la Partícula , Ratas , Absorción Cutánea , Solubilidad , Zidovudina/administración & dosificación , Zidovudina/química , Zidovudina/farmacocinética
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