Floating poly(lactic-co-glycolic acid)-based controlled-release drug delivery system for intravesical instillation

OBJECTIVES: To investigate the floating, structural, and controlled-release characteristics of a floating poly(lactic-co-glycolic acid) (PLGA)-based controlled-release drug delivery system, and determine the feasibility of this drug delivery system for intravesical instillation. METHODS: PLGA was dissolved in dimethylacetamide, then mixed with IR780 and doxorubicin (DOX) to prepare a drug delivery system capable of solidification and flotation on water at room temperature. Preparations of PLGA, PLGA+IR780, PLGA+DOX, and PLGA+IR780+DOX were formulated. Their floating characteristics in vivo and in vitro were investigated, along with their structural and controlled-release characteristics. Preparations of saline, DOX, and PLGA+IR780+DOX were also formulated; the content of DOX in bladder tissue delivered by each preparation was determined by fluorescence microscopy. RESULTS: PLGA exhibited stable flotation in vivo and in vitro. A honeycomb structure was observed by scanning electron microscopy. When irradiated with a near-infrared laser, IR780 generated heat that vitrified PLGA, allowing controlled release of DOX from the drug delivery system. The PLGA+IR780+DOX preparation achieved the highest content of DOX in bladder tissue. CONCLUSIONS: Our floating PLGA-based controlled-release drug delivery system exhibited a honeycomb stabilized structure and achieved controlled release when irradiated by a near-infrared laser, making it an ideal drug delivery system for intravesical instillation.