Preparation Method Of Pavarerine Hydrochloride Lecithin Microemulsion And The Research On Its Transdermal Absorption

Background:The most common question about skin flap in tissue repair is that partial or total flap necrosis.There are many factories involved in path mechanism of flap necrosis, so many methods to partial or whole of the body were done to improve the survival rate by synthesize,Although precautionary and therapeatic ways through many medicines,such as vasodilator agent,anticoagulant drugs,anti-white blood cell adhesion drugs as well as adrenal cortex hormone,were applied,it was impossible to be generous used in clinic for side effect or common effect of these drugs.So study and research were undertaking to produce transcutaneous absorption praeparatum in order to avoid or reduce side effect and elevate therapeutic effect.Because local application was a full affection way,many transcutaneous absorption praeparatums were used to improve blood transportation of skin flap.The anticoagulation of Heparin could elevate vascular patency rate.When low dose of Heparin was local applied(the dose could not effect systemic blood coagulation function),it could decrease the danger of skin flap hemorrhage and hematoma and increase the ability to against vein congestion.The research had proved that:micro molecular substance could permeate through skin tissue easily under hydration corneum cases;Low Molecular Heparin had the same affection as Heparin.And another research had proved that nanometer liposome had satisfactory promotion for absorption of low Molecular Heparin per nasal mucosa.PGE₁ could expand blood vessel,anti-platelet aggregation and decrease oxygen-derived free radicals.The researcher found that PGE1 content exceeded in smooth muscle of arteries than of veins,when they painted different concentration PGE₁ of extemai applied cream which contained cutaneous permeable agent on animal ischemia flap.Because papaverine hydrochloride had relaxation function to smooth muscle of blood vessel, gastrointestinal tract and bile duct,people used it to prevent and cure flap ischemia through intravenous route.But we should need large dosage and short interval time, and some time we got larger side effect.Early some one produced external preparation contained paparerine hydrochloride,which could treat impotence.Lately, some one proved that papaverine hydrochloride gelata and cream could be absorpted through skin and promote expansion velocity to improve blood transportation of skin and raise survival rate of skin flap.Pharmacal concentration gradient and electrochemistry gradient was important to medicine permeation through skin;However the key point of rate limiting was comeum and epidermis during medicine permeation process through comeum, epidermis and dermis,but skin slap especially avulsed skin flap was different from normal skin,the mechanisms and efficiency of drug transdermal absorption were also different,so the important point of research was how to raise penetrative effection. Recently Different penetrative methods were applied in different medicines.At present micro emulsion was introduced to transdermal-drug delivery system and became research hot spot,and more and more people put attention to this.Particle diameter of micro emulsion was only 10-100nm,it had strong penetrating power. There are many advantages:When it was a sort of carrier,it would increase drug solubility and bioavailability;it could be fast and full absorpted and strengthen curative effect and lower toxic action and side effect;The transdermal-drug delivery system was stable and delivered by oral,injection and per nasal administration; Microporous membrane could sterilization;and so on.Consequently to develop papaverine hydrochloride lecithin micro emulsion and investigate the ability of tansdermal absorption were in order to offer some dates for clinical research. Objectives:1.To discover a medical prescription through pseud- ternary phase diagram and orthogonal design,then to inspect its maximum dosage and stability.2.To study and research permeate capability and reason of papaverefine hydrochlofide lecithin micro emulsion on vitro skin.3.To detect pavarerine hydrochloride content in pavarefine hydrochloride lecithin microemulsion and transudation Using highper formance liquid chromatography (HPLC)Methods:1.HPLC detected pavarerine hydrochloride content:used ultra-violet detector. Prepared papavererine hydrochloride standard liquor,established standard curvilinear equation and determined papavererine hydrochloride peak area,at last calculated content.The separation was made by using a C₁₈ column with isocratic mobile phase which was consisted of methanol:water:triethylamine (60:40:0.001)(ν:ν:w),the flow rate was 1.0ml/min and the detective wavelength was 248nm.2.Preparation of lecithine micro emulsion:(1)choice of the base micro emulsion system:first to define Km(Kin =cosurfactant/surfactant,this text used surfactant and cosurfactant mingle zoarium as AS,oil phase as O,water as W, microemulsion as M.),then mixed with oil(different percent,AS/0=9:I,8:2, 7:3,…1:9)in test tube with bung,added water and observed change in test tube. We found monophase microemulsion region was clear.At last detected the base micro emulsion.(2)Qptimized prescription:choose km,dosage of surfactant and cosurfactant all the three factors,three concentration level and made orthogonal design to observe the impaction on viscosity,particle diameter,conductivity,homeostasis flow rate in vitro from every factor.Choose micro particle diameter,higher dosage and homeostasis flow rate in vitro as best prescription.(3) Detection of solubility:added excess papaverine hydrochloride in the same volume of IPM,alchol,PC,blank micro emulsion and pure wanter, then gave them ultrasonic waves,after 15min,we surged them under 37℃for 24 hours.These solution was efferenced with 30000r.min^-1 and detected by HPLC. Prepared papaverine hydrochloride lecithin micro emulsion,suspend liquid and water solution contained papaverine hydrochloride.The papaverine hydrochloride dosages were all 20mg in these drugs.We inspected homeostasis flow rate and time lag,then drawed accumulated releasing drug curve.(4) Detection of stability:put papaverine hydrochloride lecithin micro emulsion in sealed bottle,at 0,1,2,3,6month,detected color,particle size,contents of papaverine hydrochloride.3.Prepared papaverine hydrochloride lecithin micro emulsion,suspend liquid and water solution contained papaverine hydrochloride.The papaverine hydrochloride dosages were all 20mg in these drugs.We inspected homeostasis flow rate and time lag,then drawed accumulated releasing drug curve.Results:1.A linearity was obtained in the range of 0.1812～0.6040ug·ml^-1(r =0.9999).The recovery for different dosage(80%,100%,120%) of papaverine hydrochloride lecithin micro emulsion were 97.94%,99.4%,98.12%,the average recovery was 98.51%,The relative standard deviations of intra-day assay were 0.44%0.4% 0.50%,The average relative standard deviations was 0.82%,n =5.The retention time was 9～10min.Adjuvant in drugs was not interference to assay2.Micro emulsion region viscosity ratio was larger when took isopropyl alcohol and n-butyl alcohol as cosurfactant,and we found gelatum.But it was reverse side to ethanol.It did not appear micro emulsion in peanut oil and soybean salad oil. Major region micro emulsion emerged from IPM.Area of micro emulsion did not change with km.According experimental result,IPM/lecithin/alcohol system fitted the requirement of drug praeparatum,which was coincidence with report from literature.A large homeostasis flow rate and dosage of drug and a little particle diameter was obtained when water phase:oil phase:Km(lecithin: alcohol=1:1)(w:w:w) was 10:20:70.3.One way ANOVA was used in vitro transdermal tests about three praeparatums which displayed significant disparity(p＜0.05),transdermal time lag had no significant disparity.Micro emulsion had maximum homeostasis flow rate, opposite aqueous solution minimum.Conclusions:1.The prescription is reasonable.Preparation technology is simple.Tests in vitro have evident permeation effect.2.The established method is showed to be sensitive,accurate and simple for the determination of papaverin hydrochloride in micro emulsion and permeation invitro.