Curcumol Intravenous Submicron Emulsion

Curcumol is one of the monomer compounds separated from Zedoary turmeric oil, which has pharmacologic actions of anti-bacteria, anti-virus, anti-tumor, anti-mutation, protecting liver and so on. On account of its complex component, poor stability and quality control, and the high concentration of tween 80 in the formulation, Zedoary turmeric oil was found to have some adverse reactions in clinical application. As the main active ingredient and quality control index of Zedoary turmeric oil, curcumol has been paid wide attention to the research of its pharmacological activity and mechanism, especially on anti-bacteria, anti-virus and anti-tumor. Poor water-solubility and instability of curcumol restricts further research and development of curcumol seriously. The research project "Curcumol Submicroemulsion for Intravenous Injection" was established to develop the drug delivery system without conventional cosolvent.A GC method was established by systematic method verification to determine the content and related substances of Curcumol and its submicroemulsion. The solubility and stability of curcumol bulk material in different solvent system were inspected and evaluated to provide references and basis for the formulation design of new drug delivery system. Curcumol with higher lipophilicity was dissolved in refined vegetable oils, then the lecithin (S75) and poloxamer (F68) were taken as emulsifiers, and then the mixture was prepared into a O/W submicroemulsion by high pressure homogenizer. Taking appearance, mean particle size and size distribution, demixing or not after centrifugalization and content changes of emulsion before and after the sterilization as index, the single factor test and orthogonal test were designed to evaluate and investigate the influence of the oil, emulsifier, preparation process parameters etc.on the stabilization of emulsion. Curcumol submicroemulsion was prepared successfully and its mean particle size is less than 150nm with a normal size distribution, its zeta potential less than -25mV, and it can be sterilized by autoclave(115℃,30min). The results of determination of the appearance, the particle size, pH, the content and related substances indicated that the emulsion with drug loading of 1mg/mL～6mg/mL were stable at 4℃and 25℃for 9 months and at the acceleration condition of 30℃and 40℃for 6 months.Taking buagafuran as internal standard, a GC method was developed for the determination of curcumol in rat plasma and mice tissue. Under the assay condition, the internal standard and curcumol are for good separation; the endogenous substance and metabolites from blank plasma and tissues including heart, liver, spleen, lung and kidney is non-interference to the determination. Using curcumol injection prepared with Cremophor EL as reference preparation, the concentration-time curve in rat and tissue distribution in mice were investigated after intravenous administration of curcumol submicroemulsion. The pharmacokinetics results demonstrated that the AUC was no significant differences on the two Curcumol preparations. But the apparent distribution volume of emulsion was evidently higher and its elimination rate was slightly faster than those of the injection. It clued to that submicroemulsion after injecting administrated can be transferred quickly to peripheral tissues which meet general characteristics of particulate preparation. Moreover, the mean residence time (MRT) of emulsion was obviously shortened in 4h and prolonged in long time than injection. The result of tissue distribution study in mice showed that compared with the curcumol injection,the drug distribution of curcumol submicroemulsion was reduced in heart and kidney, and no obvious changes in liver and spleen, while in lung the drug concentration was increased significantly.The results of special safety tests indicated that there was no hemolyzation and agglomeration on rabbit erythrocyte in vitro with the clinical using concentration; no vascular stimulation such as turgescence, congestion, sclerosis etc. Curcumol submicroemulsion were injected to guinea pigs at the dose of 20mg/kg by i.p. q.o.d×3, and only slight allergic reaction on guinea pig were observed after i.v. administration stimulation of curcumol submicroemulsion at the dose of 40mg/kg in the 10th day at the end of i.p. administration, and all of the symptoms disappeared in 5min. Compared with curcumol submicroemulsion, severe hypersensitive reaction with the symptoms such as unsteady gait, jumping, twitch and cachexia occurred immediately after administrated curcumol injection in the same way. Curcumol anti-bacterial experiments in vitro showed that the value of MIC to 26 strains were more than 6.72mg/mL, that is, there is no obvious anti-bacterial effect. The external anti-virus effect of curcumol by using cell infection model were judged by means of the observation to the cell changes. It was showed that curcumol was able to correspondingly restrain the influenza virus A, with IC₅₀ 243.71μg/mL, SI 11.84; and was markedly against the CVB3, with IC₅₀ 78.79μg/mL, SI 12.2. The anti-virus effect of curcumol in mice indicated that pulmonary-index was decreased significantly after intravenous administration of curcumol submicroemulsion at the dose of 10mg/kg/d (P<0.05)～40mg/kg/d (P<0.01), and splenic-index was increased obviously at the dose of 40mg/kg/d (P<0.01). It comes to the conclusion that curcumol submicroemulsion can improve the immunity and has better therapeutic effect to viral pneumonia in mice caused by influenza virus. The effect of anti-tumor(uterine cervical carcinoma,U14) in mice vivo was not observed after intravenous administration of curcumol submicroemulsion at the dose of 30mg/kg/d～120mg/kg/d.There are no organic solvents, tween 80 or polyoxyethylene castor oil etc.as cosolvent in the formulation of Curcumol submicroemulsion. It can efficiently improve the drug loading, decrease allergic reaction and adverse reaction, meliorate drug tissue distribution to make the drug concentration decreased in heart and kidney, while increased in lung. Curcumol submicroemulsion has good quality stability, so it is fitted to be used for injecting administration. Curcumol submicroemulsion is expected to develop into a therapeutic drug on viral pneumonia or viral enteritis in the near future.