Development of a sprayable thermosensitive hydrogel containing rambutan (Nephelium lappaceum L) leaf extract for diabetic wound therapy

Background/Aim: Diabetic wounds are challenging to treat due to impaired healing processes. This study aimed to develop a sprayable thermosensitive hydrogel incorporating rambutan (Nephelium lappaceum L) leaf extract, known for its phytochemical wound healing potential.

Methods

Rambutan leaves were extracted via 70 % ethanol maceration. Qualitative and quantitative analyses confirmed the presence of tannins and flavonoids. The extract was formulated into thermosensitive hydrogels (F1-F3) using sodium alginate, Poloxamer 407 and Poloxamer 188. Physical properties were evaluated and wound healing efficacy was tested on diabetic rats over 21 days using a full-thickness wound model.

Results

The extract yielded 25.44 % with tannin and flavonoid contents of 2.94 % and 5.73 %, respectively. All formulations were homogeneous, pH-balanced (4.52-5.03) and met ideal criteria for spreadability, gelation, swelling and viscosity. In vivo tests showed F3 had the highest wound healing rate (81.25 %), approaching the normal control (84.00 %) and outperforming the reference drug (61.67 %). Statistical analysis indicated significant differences (p < 0.05).