The use of water‐soluble mucoadhesive gels for the intravesical delivery of epirubicin to the bladder for the treatment of non‐muscle‐invasive bladder cancer

Objectives To develop an epirubicin‐loaded, water‐soluble mucoadhesive gels that have the correct rheological properties to facilitate their delivery into the bladder via a catheter, while allowing for their spread across the bladder wall with limited expansion of the bladder and increasing the retention of epirubicin in the bladder and flushing with urine. Methods Epirubicin‐loaded hydroxyl ethyl cellulose ( HEC ) and hydroxy propyl methyl cellulose ( HPMC ) gels were manufactured and tested for their rheological properties. Their ability to be pushed through a catheter was also assessed as was their in‐vitro drug release, spreading in a bladder and retention of epirubicin after flushing with simulated urine. Key findings Epirubicin drug release was viscosity‐dependent. The 1 and 1.5% HEC gels and the 1, 1.5 and 2% HPMC gels had the correct viscosity to be administered through a model catheter and spread evenly across the bladder wall under the pressure of the detrusor muscle. The epirubicin‐loaded gels had an increased retention time in the bladder when compared with a standard intravesical solution of epirubicin, even after successive flushes with simulated urine. Conclusion The increased retention of epirubicin in the bladder by the HEC and HPMC gels warrant further investigation, using an in‐vivo model, to assess their potential for use as treatment for non‐muscle‐invasive bladder cancer.