Effects Of The Essential Oil From Cyperus Rotundus L. On Percutaneous Permeability Of Benzodiazepine In Vitro

ObjectiveTo study transdermal permeability of essential oil from Cyperus rotundus L.and its effect on percutaneous absorption of benzodiazepine.MethodTo establish HPLC methods for determination of benzodiazepine(nitrazepam，diazepam，oxazepam and clonazepam) and α-cyperone which is themajor constituent of essential oil from Cyperus rotundus L.. Rat skin was usedas permeation barrier,four benzodiazepines were selected as model drugs andazone as control group. The transdermal characteristics were investigated usingFranz diffusion cell.Results1. The calibration curve of α-cyperone was liner in the range of0.5554~ 111.1μg·mL-1. The regression equation was Y=23.90C+12.70(r=0.9998).The relative recovery was99.63%, the intra-day and inter-day reproducibilitywere good with the RSD of2.0%or below.The calibration curve of nitrazepam was liner in the range of0.05700~22.80μg·mL-1. The regression equation was Y=66.32C+3.652(r=0.9999).The relative recovery was99.00%, the intra-day and inter-day reproducibilitywere good with the RSD of1.1%or below.The effect of the essential oil from Cyperus rotundus L. wasconcentration-dependent on percutaneous absorption of nitrazepam.In thisstudy,5.0%essential oil from Cyperus rotundus L. has the best results and has ahigher effect than azone.2. The calibration curve of α-cyperone was liner in the range of0.1110~44.40μg·mL-1. The regression equation was Y=25.44C+10.43(r=0.9996). The relative recovery was99.48%, the intra-day and inter-dayreproducibility were good with the RSD of2.0%or below.The calibration curve of diazepam was liner in the range of0.06500~26.00μg·mL-1. The regression equation was Y=63.75C+0.6033(r=0.9999). Therelative recovery was99.33%, the intra-day and inter-day reproducibility weregood with the RSD of2.0%or below.The effect of the essential oil from Cyperus rotundus L. was smaller onpercutaneous absorption of diazepam.In this study,3.0%essential oil fromCyperus rotundus L. has the best results and has smaller effect than azone.3. The calibration curve of oxazepam was liner in the range of0.06000~24.00μg·mL-1. The regression equation was Y=112.4C–2.656(r=0.9998). The relative recovery was99.85%, the intra-day and inter-dayreproducibility were good with the RSD of2.0%or below. The effect of the essential oil from Cyperus rotundus L. was smaller onpercutaneous absorption of oxazepam and has smaller effect than azone.4. The calibration curve of α-cyperone was liner in the range of0.08500~10.20μg·mL-1. The regression equation was Y=74.28C–0.2142(r=0.9999). The relative recovery was99.16%, the intra-day and inter-dayreproducibility were good with the RSD of3.0%or below.The calibration curve of clonazepam was liner in the range of0.07300~29.20μg·mL-1. The regression equation was Y=53.22C+6.922(r=0.9999).The relative recovery was100.2%, the intra-day and inter-day reproducibilitywere good with the RSD of2.4%or below.The effect of the essential oil from Cyperus rotundus L. wasconcentration-dependent on percutaneous absorption of clonazepam.In thisstudy,5.0%essential oil from Cyperus rotundus L. had the best results and hashigher effect than azone on percutaneous absorption of clonazepam. Thepermeability coefficients of clonazepam in1.0%essential oil from Cyperusrotundus L. for the rat skin was6.88times as much as that in normal saline.ConclusionsThe essential oil from Cyperus rotundus L. can enhance the percutaneousabsorption of nitrazepam and clonazepam in vitro.5.0%essential oil fromCyperus rotundus L. showed significant penetration enhancing effect and wassuperior to azone.But the essential oil can weakly enhance the percutaneousabsorption of diazepam and oxazepam in vitro.Although3.0%essential oil hadthe best results,their effects were less than azone. The ransdermal permeabilityof essential oil from Cyperus rotundus L. and its effect on percutaneousabsorption of benzodiazepine may be related to the structure and lipotropism ofits molecule.