The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Tejraj M Aminabhavi - One of the best experts on this subject based on the ideXlab platform.
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controlled release of diclofenac sodium and ibuprofen through beads of sodium alginate and Hydroxy Ethyl Cellulose blends
Journal of Applied Polymer Science, 2006Co-Authors: M C S Subha, Vijaya Kumar B Naidu, M Sairam, N N Mallikarjuna, Tejraj M AminabhaviAbstract:Received 19 November 2005; accepted 16 March 2006DOI 10.1002/app.25087Published online in Wiley InterScience (www.interscience.wiley.com).ABSTRACT: Controlled release of diclofenac sodium (DS)and ibuprofen (IB) drugs through sodium alginate (NaAlg)-Hydroxy Ethyl Cellulose (HEC) blend polymeric beads hasbeen investigated. Beads were prepared by precipitating theviscous solution of NaAlg and HEC blend in alcohol fol-lowed by crosslinking with calcium chloride. Different for-mulations were developed in bead form by varying theamount of HEC, crosslinking agent, and drug concentration.Swelling studies in water, percent encapsulation of drugs,and release studies were carried out. The DS-loaded beadshave shown better release performance than the IB-loadedbeads. Diffusion parameters were evaluated from the Fick-ian diffusion theory. Mathematical modeling studies anddrug release characteristics through bead matrices werestudied by solving Fick’s diffusion equation. The results arediscussed in terms of drug release patterns and theoreticalconcentration profiles generated through matrices, consider-ing spherical geometry of the beads.
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thermodynamics hydrodynamics of aqueous polymer solutions and dynamic mechanical characterization of solid films of chitosan sodium alginate guar gum Hydroxy Ethyl Cellulose and Hydroxypropyl mEthylCellulose at different temperatures
Carbohydrate Polymers, 2006Co-Authors: Venkatesh Mutalik, M Sairam, Lata S Manjeshwar, Ashwini Wali, K V S N Raju, Tejraj M AminabhaviAbstract:Experimental densities and viscosities of five important carbohydrate polymers viz. chitosan, sodium alginate, guar gum, Hydroxy Ethyl Cellulose and Hydroxypropyl mEthylCellulose have been measured in aqueous media at five different temperatures and at nine weight fractions. Using the density data, excess molar volumes have been computed. Mathematical equations are proposed to calculate the activity, which agreed well with the experimental data. Viscosity data at different concentrations of carbohydrate polymer solutions have been used to calculate the viscosity average molecular weight of the polymers. Thin free standing films of these polymers have been prepared by solution casting method and were tested for dynamic mechanical behavior as well as glass transition of the polymers were evaluated by dynamic mechanical testing analyzer and thermogravimetry, respectively.
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Thermodynamics/hydrodynamics of aqueous polymer solutions and dynamic mechanical characterization of solid films of chitosan, sodium alginate, guar gum, Hydroxy Ethyl Cellulose and Hydroxypropyl mEthylCellulose at different temperatures
Carbohydrate Polymers, 2006Co-Authors: Venkatesh Mutalik, M Sairam, Lata S Manjeshwar, Ashwini Wali, K V S N Raju, Tejraj M AminabhaviAbstract:Experimental densities and viscosities of five important carbohydrate polymers viz. chitosan, sodium alginate, guar gum, Hydroxy Ethyl Cellulose and Hydroxypropyl mEthylCellulose have been measured in aqueous media at five different temperatures and at nine weight fractions. Using the density data, excess molar volumes have been computed. Mathematical equations are proposed to calculate the activity, which agreed well with the experimental data. Viscosity data at different concentrations of carbohydrate polymer solutions have been used to calculate the viscosity average molecular weight of the polymers. Thin free standing films of these polymers have been prepared by solution casting method and were tested for dynamic mechanical behavior as well as glass transition of the polymers were evaluated by dynamic mechanical testing analyzer and thermogravimetry, respectively.
Vivek Sharma - One of the best experts on this subject based on the ideXlab platform.
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the rheology of aqueous solutions of Ethyl Hydroxy Ethyl Cellulose ehec and its hydrophobically modified analogue hmehec extensional flow response in capillary break up jetting rojer and in a cross slot extensional rheometer
Soft Matter, 2015Co-Authors: Vivek Sharma, Simon J Haward, James G Serdy, Bavand Keshavarz, Asa Soderlund, Phil Threlfallholmes, Gareth H MckinleyAbstract:Cellulose derivatives containing associating hydrophobic groups along their hydrophilic backbone are used as rheology modifiers in the formulation of water-based spray paints, medicinal sprays, cosmetics and printable inks. Jetting and spraying applications of these materials involve progressive thinning and break-up of a fluid column or sheet into drops. Strong extensional kinematics develop in the thinning fluid neck. In viscous Newtonian fluids, inertial and viscous stresses oppose the surface tension-driven instability. In aqueous solutions of polymers such as Ethyl Hydroxy-Ethyl Cellulose (EHEC), chain elongation provides additional elastic stresses that can delay the capillary-driven pinch-off, influencing the sprayability or jettability of the complex fluid. In this study, we quantify the transient response of thinning filaments of Cellulose ether solutions to extensional flows in a Capillary Break-up Extensional Rheometer (CaBER) and in a forced jet undergoing break-up using Rayleigh Ohnesorge Jetting Extensional Rheometry (ROJER). We also characterize the steady state molecular deformations using measurements of the flow-induced birefringence and excess pressure drop in an extensional stagnation point flow using a Cross-Slot Extensional Rheometer (CSER). We show that under the high extension rates encountered in jetting and spraying, the semi-dilute solutions of hydrophobically modified Ethyl Hydroxy-Ethyl Cellulose (hmEHEC) exhibit extensional thinning, while the unmodified bare chains of EHEC display an increase in extensional viscosity, up to a plateau value. For both EHEC and hmEHEC dispersions, the low extensibility of the Cellulose derivatives limits the Trouton ratio observed at the highest extension rates attained (close to 105 s−1) to around 10–20. The reduction in extensional viscosity with increasing extension rate for the hydrophobically modified Cellulose ether is primarily caused by the disruption of a transient elastic network that is initially formed by intermolecular association of hydrophobic stickers. This extensional thinning behavior, in conjunction with the low extensibility of the hydrophobically modified Cellulose ether additives, makes these rheology modifiers ideal for controlling the extensional rheology in formulations that require jetting or spraying, with minimal residual stringiness or stranding.
Venkatesh Mutalik - One of the best experts on this subject based on the ideXlab platform.
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thermodynamics hydrodynamics of aqueous polymer solutions and dynamic mechanical characterization of solid films of chitosan sodium alginate guar gum Hydroxy Ethyl Cellulose and Hydroxypropyl mEthylCellulose at different temperatures
Carbohydrate Polymers, 2006Co-Authors: Venkatesh Mutalik, M Sairam, Lata S Manjeshwar, Ashwini Wali, K V S N Raju, Tejraj M AminabhaviAbstract:Experimental densities and viscosities of five important carbohydrate polymers viz. chitosan, sodium alginate, guar gum, Hydroxy Ethyl Cellulose and Hydroxypropyl mEthylCellulose have been measured in aqueous media at five different temperatures and at nine weight fractions. Using the density data, excess molar volumes have been computed. Mathematical equations are proposed to calculate the activity, which agreed well with the experimental data. Viscosity data at different concentrations of carbohydrate polymer solutions have been used to calculate the viscosity average molecular weight of the polymers. Thin free standing films of these polymers have been prepared by solution casting method and were tested for dynamic mechanical behavior as well as glass transition of the polymers were evaluated by dynamic mechanical testing analyzer and thermogravimetry, respectively.
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Thermodynamics/hydrodynamics of aqueous polymer solutions and dynamic mechanical characterization of solid films of chitosan, sodium alginate, guar gum, Hydroxy Ethyl Cellulose and Hydroxypropyl mEthylCellulose at different temperatures
Carbohydrate Polymers, 2006Co-Authors: Venkatesh Mutalik, M Sairam, Lata S Manjeshwar, Ashwini Wali, K V S N Raju, Tejraj M AminabhaviAbstract:Experimental densities and viscosities of five important carbohydrate polymers viz. chitosan, sodium alginate, guar gum, Hydroxy Ethyl Cellulose and Hydroxypropyl mEthylCellulose have been measured in aqueous media at five different temperatures and at nine weight fractions. Using the density data, excess molar volumes have been computed. Mathematical equations are proposed to calculate the activity, which agreed well with the experimental data. Viscosity data at different concentrations of carbohydrate polymer solutions have been used to calculate the viscosity average molecular weight of the polymers. Thin free standing films of these polymers have been prepared by solution casting method and were tested for dynamic mechanical behavior as well as glass transition of the polymers were evaluated by dynamic mechanical testing analyzer and thermogravimetry, respectively.
M Sairam - One of the best experts on this subject based on the ideXlab platform.
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controlled release of diclofenac sodium and ibuprofen through beads of sodium alginate and Hydroxy Ethyl Cellulose blends
Journal of Applied Polymer Science, 2006Co-Authors: M C S Subha, Vijaya Kumar B Naidu, M Sairam, N N Mallikarjuna, Tejraj M AminabhaviAbstract:Received 19 November 2005; accepted 16 March 2006DOI 10.1002/app.25087Published online in Wiley InterScience (www.interscience.wiley.com).ABSTRACT: Controlled release of diclofenac sodium (DS)and ibuprofen (IB) drugs through sodium alginate (NaAlg)-Hydroxy Ethyl Cellulose (HEC) blend polymeric beads hasbeen investigated. Beads were prepared by precipitating theviscous solution of NaAlg and HEC blend in alcohol fol-lowed by crosslinking with calcium chloride. Different for-mulations were developed in bead form by varying theamount of HEC, crosslinking agent, and drug concentration.Swelling studies in water, percent encapsulation of drugs,and release studies were carried out. The DS-loaded beadshave shown better release performance than the IB-loadedbeads. Diffusion parameters were evaluated from the Fick-ian diffusion theory. Mathematical modeling studies anddrug release characteristics through bead matrices werestudied by solving Fick’s diffusion equation. The results arediscussed in terms of drug release patterns and theoreticalconcentration profiles generated through matrices, consider-ing spherical geometry of the beads.
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thermodynamics hydrodynamics of aqueous polymer solutions and dynamic mechanical characterization of solid films of chitosan sodium alginate guar gum Hydroxy Ethyl Cellulose and Hydroxypropyl mEthylCellulose at different temperatures
Carbohydrate Polymers, 2006Co-Authors: Venkatesh Mutalik, M Sairam, Lata S Manjeshwar, Ashwini Wali, K V S N Raju, Tejraj M AminabhaviAbstract:Experimental densities and viscosities of five important carbohydrate polymers viz. chitosan, sodium alginate, guar gum, Hydroxy Ethyl Cellulose and Hydroxypropyl mEthylCellulose have been measured in aqueous media at five different temperatures and at nine weight fractions. Using the density data, excess molar volumes have been computed. Mathematical equations are proposed to calculate the activity, which agreed well with the experimental data. Viscosity data at different concentrations of carbohydrate polymer solutions have been used to calculate the viscosity average molecular weight of the polymers. Thin free standing films of these polymers have been prepared by solution casting method and were tested for dynamic mechanical behavior as well as glass transition of the polymers were evaluated by dynamic mechanical testing analyzer and thermogravimetry, respectively.
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Thermodynamics/hydrodynamics of aqueous polymer solutions and dynamic mechanical characterization of solid films of chitosan, sodium alginate, guar gum, Hydroxy Ethyl Cellulose and Hydroxypropyl mEthylCellulose at different temperatures
Carbohydrate Polymers, 2006Co-Authors: Venkatesh Mutalik, M Sairam, Lata S Manjeshwar, Ashwini Wali, K V S N Raju, Tejraj M AminabhaviAbstract:Experimental densities and viscosities of five important carbohydrate polymers viz. chitosan, sodium alginate, guar gum, Hydroxy Ethyl Cellulose and Hydroxypropyl mEthylCellulose have been measured in aqueous media at five different temperatures and at nine weight fractions. Using the density data, excess molar volumes have been computed. Mathematical equations are proposed to calculate the activity, which agreed well with the experimental data. Viscosity data at different concentrations of carbohydrate polymer solutions have been used to calculate the viscosity average molecular weight of the polymers. Thin free standing films of these polymers have been prepared by solution casting method and were tested for dynamic mechanical behavior as well as glass transition of the polymers were evaluated by dynamic mechanical testing analyzer and thermogravimetry, respectively.
Gareth H Mckinley - One of the best experts on this subject based on the ideXlab platform.
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the rheology of aqueous solutions of Ethyl Hydroxy Ethyl Cellulose ehec and its hydrophobically modified analogue hmehec extensional flow response in capillary break up jetting rojer and in a cross slot extensional rheometer
Soft Matter, 2015Co-Authors: Vivek Sharma, Simon J Haward, James G Serdy, Bavand Keshavarz, Asa Soderlund, Phil Threlfallholmes, Gareth H MckinleyAbstract:Cellulose derivatives containing associating hydrophobic groups along their hydrophilic backbone are used as rheology modifiers in the formulation of water-based spray paints, medicinal sprays, cosmetics and printable inks. Jetting and spraying applications of these materials involve progressive thinning and break-up of a fluid column or sheet into drops. Strong extensional kinematics develop in the thinning fluid neck. In viscous Newtonian fluids, inertial and viscous stresses oppose the surface tension-driven instability. In aqueous solutions of polymers such as Ethyl Hydroxy-Ethyl Cellulose (EHEC), chain elongation provides additional elastic stresses that can delay the capillary-driven pinch-off, influencing the sprayability or jettability of the complex fluid. In this study, we quantify the transient response of thinning filaments of Cellulose ether solutions to extensional flows in a Capillary Break-up Extensional Rheometer (CaBER) and in a forced jet undergoing break-up using Rayleigh Ohnesorge Jetting Extensional Rheometry (ROJER). We also characterize the steady state molecular deformations using measurements of the flow-induced birefringence and excess pressure drop in an extensional stagnation point flow using a Cross-Slot Extensional Rheometer (CSER). We show that under the high extension rates encountered in jetting and spraying, the semi-dilute solutions of hydrophobically modified Ethyl Hydroxy-Ethyl Cellulose (hmEHEC) exhibit extensional thinning, while the unmodified bare chains of EHEC display an increase in extensional viscosity, up to a plateau value. For both EHEC and hmEHEC dispersions, the low extensibility of the Cellulose derivatives limits the Trouton ratio observed at the highest extension rates attained (close to 105 s−1) to around 10–20. The reduction in extensional viscosity with increasing extension rate for the hydrophobically modified Cellulose ether is primarily caused by the disruption of a transient elastic network that is initially formed by intermolecular association of hydrophobic stickers. This extensional thinning behavior, in conjunction with the low extensibility of the hydrophobically modified Cellulose ether additives, makes these rheology modifiers ideal for controlling the extensional rheology in formulations that require jetting or spraying, with minimal residual stringiness or stranding.
