Poloxamer 407 (POL) is widely used as a thermosensitive hydrogel for intravesical instillation. When POL hydrogel is instilled in the bladder, several problems, including urinary tract obstruction, are observed. To overcome this problem, a POL‐based floating hydrogel (PFH) system was developed. Sodium bicarbonate (BC) was used as a floating agent. PFH was optimized using a central composite design with two independent variables (X₁ [POL concentration, 42.43%] and X₂ [BC concentration, 5.23%]) and three response factors (Y₁ [floating time, 240.33 s], Y₂ [duration time, 270 min], and Y₃ [viscosity, 110.39 Pa^.s]). In gel erosion and drug‐release studies in vitro, the remaining PFH fraction decreased exponentially with time, while gemcitabine release was biphasic and surface erosion‐controlled. A plot of drug release versus gel erosion showed good linearity. Visual observation for floating, gel duration, and dye release supported the time‐course behaviors of the PFH, indicating its usefulness in intravesical instillation.

中文翻译：

---

基于泊洛沙姆407的膀胱内漂浮水凝胶：使用中央复合设计，凝胶侵蚀和药物释放的统计优化

泊洛沙姆407（POL）被广泛用作膀胱内滴注的热敏水凝胶。当将POL水凝胶滴入膀胱中时，观察到一些问题，包括尿路阻塞。为了克服这个问题，开发了基于POL的浮动水凝胶（PFH）系统。碳酸氢钠（BC）被用作漂浮剂。使用中央复合设计优化PFH，该设计具有两个独立变量（X ₁ [POL浓度，42.43％]和X ₂ [BC浓度，5.23％]）和三个响应因子（Y ₁ [浮动时间，240.33 s]，Y ₂ [持续时间，270分钟]，和Y ₃ [粘度，110.39帕^。秒]）。在体外进行凝胶侵蚀和药物释放研究，剩余的PFH分数随时间呈指数下降，而吉西他滨的释放是双相的，且受表面侵蚀控制。药物释放与凝胶侵蚀的关系图显示出良好的线性。目视观察漂浮，凝胶持续时间和染料释放支持了PFH的时程行为，表明其在膀胱内滴注中很有用。