Formulation Study of Intravesical Oxybutynin Instillation Solution with Enhanced Retention in Bladder

Abstract

A formulation study of intravesical oxybutynin (OB) preparations was carried out in order to improve the effectiveness in intravesical instillation therapy for spastic neurogenetic bladder. Sodium hyaluronate (HYA) was introduced to enhance the muco-adhesiveness of the instillation preparation, and the physicochemical properties of the OB formulation were evaluated in comparison with a conventional formulation containing hydroxypropylcellulose (HPC). The viscous properties and in vitro adhesiveness increased with the amount of the polymeric additives, and retention properties of OB in rabbit bladder were comparable after addition of 0.4% HYA and 1.0% HPC. HYA was able to enhance the intravesical retention properties of OB instillation solution to a lesser degree than HPC, it seemed to be a useful additive in the OB instillation due to its safety and mucosal-protective effect.

Design and evaluation of an intravesical delivery system for superficial bladder cancer: preparation of gemcitabine HCl-loaded chitosan–thioglycolic acid nanoparticles and comparison of chitosan/poloxamer gels as carriers

“…19 Recently; in the urological field, the application of a large variety of bioadhesive polymers such as chitosan, polycarbophil, and hydroxypropylcellulose (HPC) has been reported. 38 For instance, Chiba et al 39 demonstrated that the addition of 1.0% HPC effectively prolonged oxybutynin retention in the bladder compared to intravesical instillation of its solution. Among these bioadhesives, chitosan is a featured natural copolymer exhibiting various beneficial properties such as strong bioadhesion, controlled drug-releasing properties, and permeation-enhancing properties due to its cationic character and based on its primary amino groups.…”

Irrigations and Dialysis Solutions

“…For irrigations for the bladder iso-osmosis is less important. Hypo-osmosis is more problematic than hyper-osmosis, because the osmotic value of urine is twice to thrice the osmotic value of blood [4].…”

“…Irrigations for rinsing normally should not be viscous. In solutions for intravesical use the use of a viscosity enhancer, like hypromellose, may exert a prolonged effect [4].…”