Author/Editor		Burjak, Mateja; Bogataj, Marija; Mrhar, Aleš
Title		Mukoadhezivne mikrosfere za intravezikalno aplikacijo
Type		članek
Source		In: Musar A, Florjančič U, editors. Raziskovalno delo podiplomskih študentov Slovenije: naravoslovje in tehnika. 1. dnevi podiplomskih študentov Slovenije; 2000 nov 10; Ljubljana. Ljubljana: Društvo mladih raziskovalcev Slovenije,
Publication year		2000
Volume		str. 43-52
Language		slo
Abstract		The purpose of our investigations is the preparation of mucoadhesive microspheres intended for intravesical application for the treatment of urinary bladder infections or superficial urinary bladder cancer. After the application of previously prepared microspheres suspension through catheter into urinary bladder, microspheres are expected to sedimentate and flotate, adhere on urinary bladder mucosa and release the drug over a certain period of time. During the present study, microspheres with two mucoadhesive polymers, chitosan hydrochloride and polycarbophil in ratio 1:1, were prepared and their mucoadhesive properties were evaluated on isolated pig urinary bladder mucosa. Pipemidic acid was used as model drug but its application in such system could also represent an alternative to the treatment of urinary bladder infections after systemic application. Different amounts of Span 80 were also incorporated in microspheres and the following microspheres properties were evaluated: stability of microspheres suspension, the amount of sedimented and flotated microspheres and drug release from microspheres according to USP XXIII method. Moreover, an in vitro experimental model was developed for the evaluation of drug release from adhered microspheres. This model simulates well the processes in in vivo system by performing constant influx of physiologic solution through both ureters and withdrawing the samples of solution with released drug through urethra in defined time intervals. All samples of microspheres suspended well and then flotated and sedimented. Span 80, incorporated in microspheres, significantly increased the amount of sedimented microspheres. The majority of microspheres (59-87%) adhered on bladder mucosa after instillation. The release of the drug from adhered microspheres was retarded (40-80% in 4 hours) in comparison to USP test (100% in 30-45 minutes), probably due to mucoadhesion. (Abstract truncated at 2000 characters.)
Descriptors		MICROSPHERES URINARY CATHETERIZATION PIPEMIDIC ACID ADMINISTRATION, INTRAVESICAL SWINE URINARY TRACT INFECTIONS BLADDER NEOPLASMS DRUG DELIVERY SYSTEMS