Journal of Chinese Pharmaceutical Sciences ›› 2018, Vol. 27 ›› Issue (2): 82-91.DOI: 10.5246/jcps.2018.02.009

• Original articles • Previous Articles     Next Articles

Process optimization for the enhanced stability of diclofenac potassium granules and capsules

Jiangyan Liu1#, Xiunan Li2#, Xiaoxue Zhang1, Haoyan Huang1, Liqing Chen1, Jinghao Cui1, Qingri Cao1*   

  1. 1. College of Pharmaceutical Sciences, Soochow University, Suzhou 215123, China
    2. Department of Pharmacy, Yanji City Hospital, Yanji 133000, China
  • Received:2017-12-15 Revised:2018-01-28 Online:2018-03-03 Published:2018-02-07
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  • Supported by:
    National Natural Science Foundation of China (Grant No. 81373333, 81311140267).


This study aimed to investigate the effects of different process parameters on the physical properties, in vitro dissolution rate, and short and long-term stability of diclofenac potassium (DFP) granules and capsules. DFP granules exhibited low total amounts of impurities when prepared through the wet granulation method using a granulating solvent with a low water/ethanol ratio. The impurities of the wet DFP mass dried at 70 °C were higher than those dried at 50 °C or 60 °C. DFP granules were stable under strong light exposure during preparation. DFP granules prepared using a granulating solvent with a 1:4 water/ethanol ratio had a relatively smaller particle size and higher angle of repose than those prepared using granulating solvents with other water/ethanol ratios. The dissolution rate of DFP capsules prepared using four different water/ethanol ratios was less than 2% after 10 min of dissolution and increased to 95% within 30 min of dissolution. The total amount of drug impurities of DFP capsules prepared using a granulating solvent with 1:4 water/ethanol ratio was considerably lower than those of DFP capsules prepared using a granulating solvent with a 1:0 water/ethanol solvent ratio. Regardless of the water/ethanol ratio, the capsules showed poor stability when exposed to high temperature (60 °C) and strong light (4500±500 Lux) for 10 days, but were relatively stable at high humidity (92.5% RH). The results of the long-term stability (25±2 °C and 60%±10% relative humidity) study showed that DFP granules were more stable than DFP capsules, and were stable for 12 months. The type of encapsulating material did not affect the 2-month stability of DFP. DFP granules are sensitive to granulating solvent and drying temperature and DFP capsules should be stored away from high temperature and strong light. 

Key words: Diclofenac potassium, Wet granulation, Physical properties, Stress test, Long-term stability

CLC Number: