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Drug Release of pH/Temperature‐Responsive Calcium Alginate/Poly( N ‐isopropylacrylamide) Semi‐IPN Beads

2006; Wiley; Volume: 6; Issue: 5 Linguagem: Inglês

10.1002/mabi.200600013

1616-5195

Jun Shi, Natália M. Alves, João F. Mano,

Advanced Drug Delivery Systems

Abstract Summary: A series of semi‐interpenetrating, polymer network (semi‐IPN), hydrogel beads, composed of calcium alginate (Ca‐alginate) and poly( N ‐isopropylacrylamide) (PNIPAAM), were prepared for a pH/temperature‐sensitive drug delivery study. The equilibrium swelling showed the independent pH‐ and thermo‐ responsive nature of the developed materials. At pH = 2.1, the release amount of indomethacin incorporated into these beads was about 10% within 400 min, while this value approached to 95% at pH = 7.4. The release rate of the drug was higher at 37 °C than that at 25 °C and increased slightly with increasing PNIPAAM content. These results suggest that the Ca‐alginate/PNIPAAM beads have the potential to be used as an effective pH/temperature sustainable delivery system of bioactive agents. A summary of the temperature‐ and pH‐dependence on the release of the drug over a period of 450 min. The effect of the temperature on the swelling of the beads is shown in the inset. magnified image A summary of the temperature‐ and pH‐dependence on the release of the drug over a period of 450 min. The effect of the temperature on the swelling of the beads is shown in the inset.