Preparation Technique and Dissolution Rate of Nifedipine Sustained-release Hydrogels / 中国药房

ABSTRACT

OBJECTIVE:To prepare nifedipine sustained-release hydrogels and to study their drug release in vitro.METHODS:Nifedipine sustained-release hydrogels were prepared by complex coacervation.An orthogonal experiment was performed with chitosan,concentration of sodium alginate,mixing speed and the volume ratio of chitosan solution to sodium alginate solution as factors.Meanwhile,the dissolution rate of the prepared hydrogels was determined by basket-rotating method,and pH-sensitivity of the released drug in different pH medium was investigated.RESULTS:The optimal technical condition was as followsthe concentration of chitosan was 0.4% and that of sodium alginate was 1.5%;the mixing speed was 160 r?min-1;the volume ratio of chitosan solution to sodium alginate solution was 61.The dissolution rate of sustained-release hydrogels containing nifedipine was 13.43% in simulated gastric fluid(pH 1.5) at 4 hours,which stood at 52.30% at 4 hours and 81.72% at 12 hours in simulated intestinal fluid(pH 6.8).CONCLUSION:The sustained-release hydrogels of nifedipine showed remarkable sustained-release properties and strong pH sensibility in vitro.