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Chitosan is a cationic polysaccharide widely employed as an absorption enhancer. The aim of this work was to examine the effect of chitosan on the permeability of isolated pig urinary bladder wall as well as to determine the role of calcium ions in this process. Besides permeability studies, scanning electron microscopy and fluorescent microscopy were(More)
Superficial cell desquamation followed by differentiation of newly exposed superficial cells induces regeneration of the urinary bladder epithelium, urothelium. In the present work, chitosan was evaluated as a new inducer of urothelial cell desquamation, in order to study the regeneration of mouse urothelial cells in vivo. Intravesical application of(More)
Microspheres containing the mucoadhesive polymer chitosan hydrochloride, with matrix polymer Eudragit RS, pipemidic acid as a model drug and agglomeration preventing agent magnesium stearate were prepared by the solvent evaporation method. The amount of magnesium stearate was varied and the following methods were used for microsphere evaluation: sieve(More)
Chitosan in 0.5% w/v concentration enhanced the permeability of the isolated pig urinary bladder wall by desquamation of the urothelium as ascertained in our previous study. The aim of the present work was to determine the time and concentration dependence of chitosan's effect on the permeation of a model drug into the bladder wall and to establish if the(More)
Eudragit RS 100 microspheres containing ketoprofen as a model drug were prepared by the solvent evaporation method using an acetone/liquid paraffin solvent system. The influence of various preparation temperatures: 10, 25, 35, and 40 degrees C, on particle size and morphology, drug content and release kinetics, and drug crystal state was evaluated. With(More)
The absorption and bioavailability of drugs can be substantially affected by the transit of dosage forms through the gastrointestinal (GI) tract. Gastric emptying is one of the most critical parameters contributing to this inter- and intra-individual GI transit variability. It is especially important for the delayed release dosage forms whose release(More)
The detachment forces of various polymers are frequently measured to determine their mucoadhesion strength. As the process of mucoadhesion is a consequence of interactions between the mucus layer on mucosa and mucoadhesive polymers, it is greatly dependent on mucus and polymer structure including their charge. It is also known that the glycosaminoglycan(More)
The object of our work is the preparation of a mucoadhesive drug delivery system intended for intravesical application. In the present work, microspheres with Eudragit RS matrix polymer and different mucoadhesive polymers, i.e. chitosan hydrochloride (Ch), sodium salt of carboxymethyl cellulose (CMC) and polycarbophil (PC) were prepared to evaluate their(More)
Influence of dispersions of mucoadhesive polymers chitosan and polycarbophil on permeability properties of urinary bladder was investigated in vitro on isolated porcine urinary bladder. Pipemidic acid as a model hydrophilic drug was used. Its distribution in the bladder wall was determined from actual tissue concentrations by a method based on sectioning of(More)