ABSTRACT
OBJECTIVE: To design and evaluate the formula of Weisu microemulsion-ion sensitive gel. METHODS The prescription of microemulsion-ion sensitive gel was conducted on the basis of single factor method and pseudotemary phase diagram method combining with central composite design-response surface methodology. The final formulation was evaluated by particle size, viscosity, potential, contents of naringin, hesperidin and neohesperidin. RESULTS: The optimum prescription ratio of Weisu microemulsion-ion sensitive gel was as following:volatile oil 3 g, RH-40 9 g, PEG-400 3 g, 0.3% deacetylated gellan gum made into 333 mL microemulsion gel. The results of physicochemical properties showed that microemulsion gel appearance was clear. The particle diameter was 20.14 nm. The Zeta potential was -4.04 mV. pH value was 5.43. The contents of naringin, hesperidin and neohesperidin are respectively 6.122 4, 2.094 1, 4.277 mg•mL-1. CONCLUSION: The preparation process of Weisu microemulsion gel is reasonable and feasible. The prepared microemulsion gel is system are stable.
ABSTRACT
OBJECTIVE: To prepare Usnic acid self-microemulsion, prescription optimization and evaluate its quality. METHODS: Usnic acid self-microemulsion was prepared by emulsification method using medium chain triglycerides-single linoleic acid glyceride (1:1, m/m) as oil phase, polyoxyethylene hydrogenated castor oil as emulsifier, diethylene glycol monoethyl ether as co-emulsifier. Based on the solubility test and pseudotemary phase diagram, using self-emulsifying time (t), light transmittance (T), drug equilibrium solubility (S), accumulative dissolution rate at 5 min and 60 min (Q5 min, Q60 min) as evaluation indexes, central composite design-response surface methodology was utilized to optimize oil phase ratio and ratio of emulsifier to co-emulsifier (Km) in microemulsion formulation. At the same time, the optimal formulation was verified, the morphology, particle size, drug-loading amount and dissolution of Usnic acid self-microemulsion were investigated. RESULTS: The optimal formulation was as follows as oil phase ratio of 25％, Km of 2. 0; ratio of mixed oil phase, emulsifier, co-emulsifier in the formulation was 25％, 50％, 25％. t, T, S, Q5 min and Q60 min of Usnic acid self-microemulsion prepared by optimal formulation were 1. 96 min, 87. 67％, 5. 67 mg/g, 66. 58％, 76. 73％ (all RSD<3％, n = 3),respectively. The relative errors of them to predicted values were all less than 4％ (n = 3). Usnic acid self-microemulsion was spherical droplet in shape after diluted with water. The average particle size was 39. 4 nm, average drug-loading amount was 4. 55 mg/g. Q90 min of Usnic acid self-microemulsion reached 99. 58％ in pH 6. 8 phosphate buffer (n = 3). CONCLUSIONS: Prepared Usnic acid self-microemulsion is in line with quality requirements.