Research on Novel Intravesical Drug Delivery Devices

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creative-commons.org/licenses/by-nc/4.0/) which permits unrestricted non-commercial use, distribution , and reproduction in any medium, provided the original work is properly cited. Urologists usually treat overactive bladder (OAB) with oral medications. However, when there is no response to medication , alternative methods of treatment, including botulinum toxin A injection and sacral neuromodulation, are utilized. Nevertheless, botulinum toxin A requires repeated injections, causes adverse effects such as acute urinary retention, and reduces patient's compliance to treatment due to the discomfort of multiple rounds of injection-based therapy. Sacral neuro-modulation can result in problems like lead migration, pain, and infection. Whether given orally or via injection, therapeutic drugs may induce adverse effects in other organs aside from the target organs due to their systemic distribution. Long-term drug treatment may be difficult in some cases due to adverse effects; however, this problem could be overcome by drug delivery directly to the target organ in order to minimize systemic effects. Treatment with antimuscarinic agents can induce problems among OAB patients by causing dry mouth and constipation. These adverse effects reduce patient's compliance, thereby decreasing treatment efficacy. In an attempt to overcome this problem, researchers have attempted direct instillation of oxy-butynin or lidocaine into the bladder, with results showing improvement in lower urinary tract symptoms (LUTS) [1]. However , this procedure requires repeated drug instillation using a urethral catheter, and the effects are neither continuous nor lasting. Based on the idea that devices that release drugs directly into the bladder may have potential to become a new treatment modality , several devices have been designed. One of the first devices created was the UROS bladder pump [2]. This device is a straight tube that is inserted into the bladder via cystoscopy and releases oxybutynin directly inside the bladder. Another device, the LiRIS, was designed by Lee and Cima [3]. The LiRIS device is a silicone tube, which is inserted into the bladder via cystos-copy and allows lidocaine to elute into the bladder. Research is being done aiming to create other effective tubular shaped treatment devices that facilitate drug elution into the bladder for extended periods. Implanting a device into a patient's body may be a satisfactory therapeutic modality for OAB, as it should theoretically have high efficacy while minimizing adverse effects [4]. Nonetheless, there are several issues associated with implantation of …