ABSTRACT
OBJECTIVE:To prepare nanostructured lipid carrier of adefovir dipivoxil(ADV-NLC),and optimize the formula-tion. METHODS:Using stearic acid and glycerin monostearate as solid lipid,oleic acid as liquid lipid,Gemini surfactant and poly-sorbate 80 as emulsifier,sodium dodecyl sulfate (SDS) as stabilizer,solvent dispersion ultrasonic method was used to prepare ADV-NLC. And using particle size,polydispersity index,Zeta potential,encapsulation efficiency as indexes,single factor test was conducted to screen Gemini surfactant-polysorbate 80 ratio,emulsifier dosage(ratio of emulsifier to water phase),drug-lipid ratio, solid-liquid lipid ratio. RESULTS:The formula was as follow as 3% emulsifier (Gemini surfactant-polysorbate 80 ratio of 1:2), 4.5% drug-lipid ratio,solid-liquid lipid ratio of 6:5. The average particle size of the prepared ADV-NLC was(48.83±2.65)nm, polydispersity index<0.3,Zeta potential was(-28.7±1.8)mV,encapsulation efficiency was(77.65±0.03)%(n=3). CONCLU-SIONS:ADV-NLC is successfully prepared,and the formulation is reasonable and feasible.
ABSTRACT
OBJECTIVE: To study the influences of Gemini surfactant and sodium chloride (NaCl) on the physicochemical properties and encapsulation efficiency of ofloxacin niosomes for developing new drug delivery system. METHODS: The non-ionic surfactant noisome was prepared by thin film hydration-ultrasonic method, taking non-ionic Gemini surfactant, Span80 and cholesterol as capsule wall materials and ofloxacin as model drug. And the influences of factors such as the amount of surfactant, salt and hydration volume etc on the vesicle size, Zeta potential, encapsulation efficiency, stability and in vitro release behaviors of the ofloxacin niosomes were studied and the optimal prescription was obtained. RESULTS: The encapsulation efficiency and the particle size distribution of the niosomes were significantly improved by Gemini surfactant. And the best ratio of the capsule wall materials was as follows: Span80-CHOL-Gemini=1:1:1. The influences of NaCl on the properties of the noisomes were as follows; the amount of drug loading was improved significantly and the absolute value of the Zeta potential decreased obviously with NaCl being added in the aqueous phase. The optimal NaCl concentration was 10 mg · mL-1. The in vitro release test showed that only 62.8% ofloxacin was released from the niosomes in 7 h in artificial gastric juice and artificial intestinal fluid, suggesting a good sustained release trend. CONCLUSION: Gemini surfactant niosomes show significant salt tolerance and obviously decrease the release rate of ofloxacin. The non-ionic Gemini surfactant may be used as a capsule wall material for new drug release system.