The aim of this work was to study the release mechanisms of drugs having different solubility (buflomedil pyridoxalphosphate 65%, sodium diclofenac 3.1%, nitrofutantoin 0.02% w/v,) from hydroxypropyl methylcellulose (HPMC) matrices by concomitantly studying swelling, diffusion and erosion fronts movement and drug delivery. The main goal was to clarify the role played by polymer swelling in drug...

We introduce a very simple open two-dimensional gel reactor for studying chemical patterns that arise in reaction-diffusion systems. The reactor consists of a thin disk-shaped layer of polyvinyl alcohol gel with one face in direct contact with a well-stirred flow reactor containing reactants of the chlorite-iodide-malonic acid system; the other face of the gel is in contact with a piece of tran...

Diffusion in pure gels and gels with immobilized cells was analyzed. A model of diffusion assuming a homogeneous cell distribution in gel was improved by introducing a tortuosity value. By theoretical analysis and numerical modeling it was shown that the tortuosity of a gel with immobilized cells is the product of two factors: (1) tortuosity generated by the cells, Tc, and (2) tortuosity of the...

Department of Pharmaceutical Chemistry, Devsthali Vidyapeeth College of Pharmacy, Rudharpur, Uttrakhand – 263153, India Abstract Nimesulide is a second generation non–steroidal anti–inflammatory agent, which is widely used in the long term therapy of rheumatoid arthritis, in alleviating pain and inflammation. But its short half-life (only 3–4 hr), so its causes more fluctuation. After oral admi...

The primary goal of this paper is to develop and analyze some fully discrete finite element methods for a displacement-pressure model modeling swelling dynamics of polymer gels under mechanical constraints. In the model, the swelling dynamics is governed by the solvent permeation and the elastic interaction; the permeation is described by a pressure equation for the solvent, and the elastic int...

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A covalent network of polymer can imbibe a solvent to form a gel. In a cavity on the surface of the gel, capillary force may suck the solvent out of the gel to form a pure liquid phase. We show that such osmocapillary phase separation occurs when capillarity balances osmosis, and when the diffusion of solvent in the gel prevails over the condensation of solvent from the vapor. Osmocapillary pha...

The selective removal of thin varnish layers from oil and egg tempera paintings is still an open challenge in the conservation field. In this paper, a new cleaning system was developed by using gel composed fully green components as deep eutectic solvents (DES) agar. gel, prepared admixing choline chloride -urea with EtOH-H2O agar exhibited good rheological properties terms stiffness, allowing ...

Abstract The electrospinning process was used to successfully encapsulate an anticancer drug, 5-fluorouracil (5-FU), into poly(ε-caprolactone)/gelatin (Gel) nanofiber mats (5-FU-PCL/Gel NFs). Nanofibers are recognized be potential carriers for the delivery of drugs. One safest solvent systems making PCL/Gel NF is formic acid/acetic acid (FA/AA) system. A compound solution jet drawn from a custo...