- A novel catanionic surfactant: Hexadecyltrimethylammonium dodecyl sulfate
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The novel catanionic surfactant, hexadecyltrimethylammonium dodecyl sulfate, was prepared from the equimolar aqueous solutions of cationic, hexadecyltrimethylammonium bromide, and anionic, sodium dodecyl sulfate, surfactants. The composition, structure, morphology and thermal behavior of new compound were determined by chemical, X-ray diffraction, IR and 1H NMR spectra analyses, differential scanning calorimetry, thermogravimetry and polarizing microscopy. The thermal behavior of solid crystalline CTADS is rather complex because of its polymorphism, thermotropic mesomorphism and coexistence of ordered and disordered phases below the melting temperature. There are two parallel mechanisms during heating: structural transition of the system and transition from solid crystalline to liquid crystalline phase. Several polymorphic phases, all of the bilayered structure, were observed exhibiting a change of the basic lamellar thickness with temperature. Polarizing microscopy revealed a characteristic texture of the smectic phase. WILEY-VCH Verlag GmbH, 1997.
- Toma?i?,Popovi?,Tu?ek-Bo?i?,Puci?,Filipovi?-Vincekovi?
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- Exploring the dual impact of hydrocarbon chainlength and the role of piroxicam a conventional NSAID on soylecithin/ion pair amphiphiles mediated hybrid vesicles for brain – tumor targeted drug delivery
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Development of drug delivery systems, not the drug discovery, has become more cynosures towards the efficacy of drug against the target cells. Modified hybrid cationic vesicles (HCV) were formulated using soylecithin (SLC), ion pair amphiphile (IPA, hexadecyltrimethylammonium-dodecylsulfate, HTMA+-DS-), bi-tail cationic surfactant dialkyldimethylammonium bromides (DXDABs, bis-C12 to C18) and cholesterol. Piroxicam (Px), a conventional non steroidal anti inflamatory drug (NSAID), with potent yet unexplored anticancer activity,was encapsulated in the hybrid vesicles. Dual impact of DXDABs and Px on SLC/IPA were scrutinized in the form of monolayer, bilayer and solid supported bilayer. Favourable hydrophobic inteaction between SLC/IPA and dihexadecyldimethylammonium bromide (DHDAB) as well as the intercalation of Px molecules between the amphiphiles were noticed through the surface pressure area measuremnts. Vesicles without and with Px were fairly monodisperse with positive zeta potential (Z. P.) and considerably stable upto two months. Size of the vesicles enhanced with Px incorporation. Vesicles maintain spherical morphology as revealed from the electronic microscopic studies. Differential scanning calaorimetry and FTIR studies confirm the location of Px membrane palisade that enhances the extent of hydration by increasing the proportion of H-bonding. Bilayer thickness and the spacing between two adjecent lamellar phase were investigated by combined small angle neutron scattering and small angle X-ray scattering. Atomic force microscopic studies confirm the Px induced fluidization of membrane bilayer. The entrapment efficiency of vesicles to host Px depends on the amount of IPA present in the bilayer. Px hosted cationic vesicles showed less than 2% hemolysis. The drug reigned supreme over human neuroblastoma cell line (SH-SY 5Y) when encapsulated inside the membrane and was non toxic to normal human blood cell lymphocyte (PBMC) as revealed from cytotoxicity assay.
- Guha, Pritam,Roy, Biplab,Nahak, Prasant,Karmakar, Gourab,Chang, Chien H.,Bikov, Alexey G.,Akentiev, Alexander B.,Noskov, Boris A.,Mandal, Amit K.,Kumar, Anup,Hassan,Aswal,Misono, Takeshi,Torigoe, Kanjiro,Panda, Amiya K.
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