Author/Editor     Bogataj, M; Mrhar, A; Korošec, L
Title     Evaluation of bioadhesive properties of microspheres on isolated guinea pig vesical and intestinal mucosa
Type     članek
Source     In: 14th pharmaceutical technology conference. Vol 1a; 1995 Apr 4-6; Barcelona. Barcelona,
Publication year     1995
Volume     str. 375-84
Language     eng
Abstract     Bioadhesion phenomenon on the intestinal mucosa is described well in literature, but there are very few data about the possibility of bioadhesion in urinary bladder. The structure of intestinal mucus is also much better studied as the structure of mucus in bladder. The aim of our work is to develop bioadhesive microspheres for the application in urinary bladder and to study the interactions between polymers and mucus as well as differences between intestinal and vesical mucus. Microspheres were prepared by solvent evaporation method, using acetone/liquid paraffin solvent system, magnesium stearate, Eudragit RL and HPC as matrix polymers and pipemidic acid as 934P, HPC, Eudragit E.HCl and PVP/VA as (non)bioadhesive polymers and pipemidic acid as model substance. Drug content, sedimentation, density and dissolution determinations were performed according to the standard procedures. A novel in situ method was developed to evaluate bioadhesive properties of microspheres on urinary bladder and small intestine mucosa. On the basis of dissolution results it can be concluded that Eudragit RL retards dissolution more effectively than HPC. Bioadhesion testing showed that CMCNa forms the strongest bioadhesive bonds. On the other side, PVP/VA and Eudragit E.HCl are practically nonbioadhesive. Differences in bioadhesion on intestinal and urinary bladder mucosa are substantial when using polymers containing ionized carboxyl groups (CMCNa and Carbopol 934P). The conslusion has been made that bioadhesive microspheres for intravesical application should contain polymer which would form matr ix i.e. Eudragit RL or HPC, polymer which would increase density and enable contact of microspheres with mucosa i.e. Carbopol 934P and strong bioadhesive polymer i.e. CMCNa.
Descriptors     INTESTINAL MUCOSA
BLADDER
ADMINISTRATION, INTRAVESICAL
ADHESIVENESS
MICROSPHERES
GUINEA PIGS
ANIMALS, LABORATORY
PIPEMIDIC ACID