Peristaltic Transport of a Herschel-Bulkley Fluid in a Non-Uniform Channel with Wall Effects
669 Abstract—The present study considers the peristaltic transport of a Herschel-Bulkley fluid in a two-dimensional channel of non-uniform cross section with wall properties. Using long wavelength approximation with low Reynolds number and dynamic boundary conditions, analytical expressions have been obtained stream function and time average velocity. The effects of pertinent parameters on these flow variables have been studied in both converging and diverging channel. It is observed that time average velocity increases with rigidity and stiffness in the wall.
Effect of heat transfer on the flow of herschel-bulkley fluid in a compliant channel with peristalsis: Peristaltic transport of herschel-bulkley fluid
The present study discusses the peristaltic flow of Herschel-Bulkley fluid in a two-dimensional flexible channel. The heat transfer effects are also considered and the analysis has been done by taking a non-uniform channel into account. Analytical expressions of solution have been obtained using long wavelength analysis. Influence of various emerging parameters has been sketched and discussed through graphs.
Improved Skin Penetration Using In Situ Nanoparticulate Diclofenac Diethylamine in Hydrogel Systems: In Vitro and In Vivo Studies
Delivering diclofenac diethylamine transdermally by means of a hydrogel is an approach to reduce or avoid systemic toxicity of the drug while providing local action for a prolonged period. In the present investigation, a process was developed to produce nanosize particles (about 10 nm) of diclofenac diethylamine in situ during the development of hydrogel, using simple mixing technique. Hydrogel was developed with polyvinyl alcohol (PVA) (5.8% w/w) and carbopol 71G (1.5% w/w). The formulations were evaluated on the basis of field emission scanning electron microscopy, texture analysis, and the assessment of various physiochemical properties. Viscosity (163–165 cps for hydrogel containing microsize drug particles and 171–173 cps for hydrogel containing nanosize drug particles, respectively) and swelling index (varied between 0.62 and 0.68) data favor the hydrogels for satisfactory topical applications. The measured hardness of the different hydrogels was uniform indicating a uniform spreadability. Data of in vitro skin (cadaver) permeation for 10 h showed that the enhancement ratios of the flux of the formulation containing nanosize drug (without the permeation enhancer) were 9.72 and 1.30 compared to the formulation containing microsized drug and the marketed formulations, respectively. In vivo plasma level of the drug increased predominantly for the hydrogel containing nanosize drug-clusters. The study depicts a simple technique for preparing hydrogel containing nanosize diclofenac diethylamine particles in situ, which can be commercially viable. The study also shows the advantage of the experimental transdermal hydrogel with nanosize drug particles over the hydrogel with microsize drug particles.