靶向递送5-ASA多糖复合凝胶珠的制备与性能评价OA

To achieve colonic targeted delivery of 5-aminosalicylic acid(5-ASA)and improve its stability in the gastrointestinal tract,a composite polysaccharide hydrogel drug delivery system was constructed based on ionotropic gelation method.The preparation process was systematically optimized through single-factor experiments combined with the Box-Behnken response surface method,and the optimal parameters were determined as:a mass ratio of sodium alginate-to-pectin of 3∶1,a mass fraction of total polysaccharides of 4.5%,a mass fraction of CaCl2 of 2.5%,a crosslinking time of 3.5 h,a mass fraction of chitosan of 2.5%,and a curing time of 40 min.And under this condition,the hydrogel beads achieved an encapsulation efficiency of(50.74±2.06)%.In vitro swelling experiment demonstrated a significant pH-responsive behavior of the composite hydrogel beads:minimal swelling occurred in simulated gastric fluid at pH 1.2 with a swelling rate of(85.00±1.41)%,while subsequent disintegra-tion were observed after the swelling rate in simulated intestinal fluid at pH 6.8 and colonic fluid at pH 7.4 rose to the maximum(2 267.50±118.08)%,(2 251.50±200.11)%respectively.In vitro simulated release experiments further confirmed its potential colon-targeting release characteristics:with cumulative release rates at 2 h of(4.85±0.35)%in simulated gastric fluid,(39.35±2.59)%at 4 h in simulated intestinal fluid,while(98.10±2.49)%at 9 h in colonic fluid.These findings indicate that the composite hydrogel beads effectively protected 5-ASA dur-ing gastrointestinal transit while enabling targeted release in the colon.