Intravesical delivery of 5-aminolevulinic acid from water-in-oil nano/submicron-emulsion systems.
The present work reports on the development of water-in-oil (w/o) emulsions for the intravesical administration of 5-aminolevulinic acid (ALA). The physicochemical properties of droplet size, zeta potential, and viscosity of the emulsions are characterized and the ability of the emulsions to release ALA following in vitro application is tested. The delivery systems are administered intravesically for 1 and 3 h in rats to examine the drug accumulation in bladder tissue. The mean size and zeta potential of the emulsions are 50-200 nm and -3 to -14 mV, respectively. The loading of ALA into the emulsions resulted in a slower and sustained release. The release extent was found to be inversely related to the droplet size of the emulsions. The emulsions did not increase the drug permeation into tissues during short exposure duration (1 h). When the dwell time was extended to 3 h, the systems showed a 2.7-fold increase in the ALA concentration in the bladder wall. Images of confocal laser scanning microscopy demonstrated a higher and deeper fluorescence signal, with emulsion administration, as compared to the aqueous control. Intravesical emulsion delivery provides a significant advantage for drugs targeting bladder tissues.
Fang
Jia-You
JY
Pharmaceutics Laboratory, Graduate Institute of Natural Products, Chang Gung University, 259 Wen-Hwa 1st Road, Kweishan, Taoyuan, Taiwan. fajy@mail.cgu.edu.tw
Wu
Pao-Chu
PC
Fang
Chia-Lang
CL
Chen
Chao-Huang
CH
D000283:Administration, Intravesical; D000622:Aminolevulinic Acid / Q000008:administration & dosage* / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology; D000818:Animals; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D002851:Chromatography, High Pressure Liquid; D004337:Drug Carriers / Q000737:chemistry* / Q000494:pharmacology; D004339:Drug Compounding; D004655:Emulsions; D005260:Female; D006801:Humans; D018613:Microscopy, Confocal; D049329:Nanostructures / Q000737:chemistry; D010316:Particle Size; D017319:Photosensitizing Agents / Q000008:administration & dosage* / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012715:Sesame Oil / Q000737:chemistry*; D012995:Solubility; D013501:Surface-Active Agents / Q000737:chemistry; D014018:Tissue Distribution; D001743:Urinary Bladder / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D014783:Viscosity; D014867:Water / Q000737:chemistry*
D004337:Drug Carriers; D004655:Emulsions; D017319:Photosensitizing Agents; D013501:Surface-Active Agents; D014867:Water; D012715:Sesame Oil; D000622:Aminolevulinic Acid