Study On Methyleugenol Microemulsion And Its Activity Of Killing Mites

Methyleugenol, also known as eugenol ether, induced flies ether, has wide applications in medicine and agriculture with significant acaricidal activity. Microemulsion has great potential as a drug delivery applications, it has the advantages of thermodynamically stable, low viscosity, good drug dispersion and conducive to the absorption. In recent years, it has increasingly widespread applications as a drug carrier. Based on taking advantages of microemulsion drug delivery, methyleugenol microemulsion was prepared in this study, and its quality, safety and efficacy was studied.1. Studies of preformulation of methyleugenol microemulsion: The solubility of methyleugenol in the oil phase, surfactant and cosurfactant were investigated, and the UV spectrophotometry content determination method of methyleugenol was established. The results showed that methyleugenol has good solubility in Tween80, RH40, EL35, emulsifier OP-10, ethanol, isopropanol, PEG400, IPM, IPP, vitamin E oil, jojoba oil, GTCC, EO, soya bean oil, peanut oil and castor oil, weak solubility in ethylene glycol, propylene glycol, glycerol and liquid paraffin. The calibration curve for the quantitative analysis of methyleugenol by UV spectrophotometry was A=0.0251x-0.0014(r=0.9966), the average recovery was 99.45%. The RSD of with-day and between-day precision were less than 1%, respectively.2. Studies of methyleugenol microemulsion formulation and quality evaluation: Through analysis of solubility of methyleugenol in oil phases, sufactants and cosufactants, and drawing of pseudo-ternary phase diagram, methyleugenol microemulsion formation was determined and the effect of preparing microemulsion about the different order of adding methyleugenol on microemulsion preparation were investigated to determine microemulsion preparation method. The results showed that the system of ethyl oleate/RH40/isopropanol/distilled water was easy to form microemulsion. The good stable formulation was methyleugenol 5%, RH40 24%, isopropanol 12%, ethyl oleate 4%, and distilled water 55%. The preparation method was that the prescribed amount surfactant, cosurfactant and oil were placed in a beaker, added prescribed amount oil with stirring, and then slowly dripped distilled water enough to form microemulsion. The results of quality evaluation showed that methyleugenol microemulsion was the type of oil-in-water and it was colorless, clear and well-distributed with good flowability. The microemulsion drop presented spherical shape, and the drop size averaged 18.2 nm with a polydispersity index of 0.018. The mean content of methyleugenol was 48.73 mg/mL in the methyleugenol microemulsion.3. Safety and efficacy evaluation of methyleugenol microemulsion: Skin irritation test in vitro and acaricidal experiment in vivo were used to evaluate the safety and efficacy of the methyleugenol microemulsion. The results showed that the skin after administration of the methyleugenol microemulsions in normal skin of rabbits has irritation scores of 0.2, and the injury skin had irritation scores of 0.4, indicating no irritation. The results of killing mites test in vitro showed that the microemulsions killed 10 mites within 10.00 min, and solution of methyleugenol within 78.33 min and ivermectin microemulsions within 40.00 min, which indicated that the effect of killing mites of the methyleugenol microemulsions was better than that of the methyleugenol solution and the ivermectin methyleugenol. The results of killing mites test in vivo showed that the ear canals of the tested rabbits were smooth and clean with no scar by giving the methyleugenol microemulsion at the 7th day, thereby the methyleugenol microemulsions had an excellent effect of clinical treatment.