Thymol, an important and advantageous component of many essential oils, has been applied as an antimicrobial agent in animals. To increase the duration of action of this compound in ruminants, it was decided here to prepare a controlled release carrier for thymol. Hydroxy propyl methyl cellulose (HPMC) and ethyl cellulose (EC) were used as the matrix polymer here. Mixtures of thymol with eight ...

We present an exact expression for the upscaled dynamic dispersion coefficient (D) for one-dimensional transport by Hagen-Poiseuille flow which is the basis for modeling transport in porous media idealized as capillary tubes. The theoretical model is validated by comparing the breakthrough curves (BTCs) from a 1D advection-dispersion model with dynamic D to that from direct numerical solutions ...

Psyllium has a mucilaginous property that makes it a good candidate to be utilized as an excipient in the preparation of controlled release systems. Various formulations were prepared using theophylline as a model drug and investigated with a view to achieve an ideal slow drug release profile. The addition of hydroxypropyl methylcellulose (HPMC) to psyllium significantly reduced the burst relea...

In a recent study, Chen and Liu [Comput. Phys. Comm. 150 (2003) 31] considered a one-dimensional, linear non-Fickian diffusion problem with a potential field, which, upon application of the Laplace transform, resulted in a second-order linear ordinary differential equation which was solved by means of a control-volume finite difference method that employs exponential shape functions. It is firs...

The transport of the antineoplastic drug doxorubicin (Adriamycin) in human red blood cells was investigated by measuring the net efflux from loaded cells. Previous data indicated that doxorubicin transport was a Fickian diffusion transport process of the electrically neutral molecule through the lipid domain of the cell membrane (Dalmark, 1981 [In press]). However, doxorubicin transport showed ...

We investigate the temporal scaling properties of mixing in heterogeneous permeability fields with variances ranging from very small (σ lnK = 0.01) to very large (σ lnK = 9). We quantify mixing by the scalar dissipation rate, which we estimate over a large range of temporal scales. For an initial pulse line injection, we find that moderate and strong heterogeneity induce Preprint submitted to E...

Matrix tablets were prepared using blends of xanthan gum (XG), Guar gum (GG) and ethylcellulose (EC). The polymers were combined using six different ratios; 1:1:1, 1:2:1, 1:2:2, 2:2:1, 2:1:2 and 2:1:1 to produce formulations XG1GG1EC1, XG1GG2EC1, XG1GG2EC2, XG2GG2EC1. XG2GG1EC2 and XG2GG1EC1 respectively. Metronidazole was used as the model drug. The ability of the prepared matrices to target d...

Solubility and diffusivity of Thyme, Cinnamon Oregano essential oils in nanocellulose films, with different carboxymethylation degree, were investigated view potential use active packaging applications. liquid resulted to increase the degree for both, Thyme while it was non-monotonous Cinnamon. showed higher solubility (about 20%wt) followed by Oregano. The sorption kinetics substantially Ficki...

Measurements of axial segregation of binary mixtures of glass beads having different diameters in a rotating horizontal cylinder are reported. For rotation speeds of ~ 15 rpm a mixed state quickly (within a few minutes) segregates into sharp bands of alternating large and small glass beads along the axis of rotation. Decreasing the rotation speed to ~ 5 rpm causes the bands to disappear, restor...

Water vapor sorption in films consisting of poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO) amphiphilic block copolymers has been measured gravimetrically at air relative humidity in the range 38–94% at 248C. The water sorption isotherm was obtained and compared to data for water vapor desorption (drying) for the same system. The kinetics of water vapor sorption we...