Study On The Preparation And Quality Standard Of Longxuejie Colon-target Tablets

Objective: The study was engaged in developing a oral colon-specific drug deliverysystem using Longxuejie as the model drug, and preparing Longxuejie Colon-target Tabletsassociation with pH dependence and time dependence twice principles. The new releasesystem could enhance the colon-target effect, increase the local concentration of colon,strengthen the therapeutic purpose of ulcerative colitis, raise the bioavailability of drug andreduce the side effects.Methods:①Study on the pre-prescription of Traditional Chinese MedicineLongxuejie, including the detection of raw medicine, the properties of powder, solubility,the maximum absorption of UV wavelength and other research projects. And according tothis basis, establish the release testing methods in vitro and prepare for the follow-up study.②Release degree in vitro was regarded as the evaluation index. Single-factor andorthogonal design were used to cull the prescription of the core. Meanwhile, the influencefactors of preparation parameters were investigated, thereby, to optimize the prescription ofcore and preparation process.③The various preparation parameters of different coatinglayers were determined by a large number of trial tests. And it was determined that themulti-layered coating included swelling layer and enteric layer from inside to outside. Therelease degree in pH1.0hydrochloric acid solution, pH6.8phosphate buffer and pH7.6phosphate buffer in vitro were used to calculate and verify the best formulation and coating weight gain.④The qualitative identification of Longxuejie Colon-target Tablets was usedby Thin Layer Chromatography; The quantitative identification of Longxuejie Colon-targetTablets through Loureirin B was used by HPLC. And establish the preparation qualitystandards base on this study.⑤Carry out the initial stability test and investigate thestability of Longxuejie Colon-target Tablets.Results:①The flow state of Traditional Chinese Medicine Longxuejie powder waspoor, and the TCM powder had certain moisture but not strong. The solubility ofLongxuejie powder in pH1.0hydrochloric acid solution, pH6.8phosphate buffer and pH7.6phosphate buffer, respectively:452.6μg/mL,459.5μg/mL,457.0μg/mL; The maximumabsorption of UV wavelength, respectively:275nm,273nm,280nm.②The preparationformula of core was150g Longxuejie,44g lactose,88g microcrystalline cellulose,15gcrosslinked polyvinylpyrrolidone,2g magnesium stearate and appropriate amount of3%ethanol solution of hydroxypropyl methyl cellulose.③The preparation formula of coating:the swelling layer was5g hydroxypropyl methyl cellulose,5g polyethyleneglycol–400,distilled water94.5mL; enteric layer was5g ethyl cellulose,0.5g polyacrylic resin Ⅱ,0.5g diethyl phthalate,100mL ethanol. The coating weight gain of swelling layer andenteric layer were3%and2%, respectively. The Longxuejie Colon-target Tablets almosthave no release in2h in pH1.0hydrochloric acid solution and in4h in pH6.8phosphatebuffer. They gradually bagan to release during pH7.6phosphate buffer and the accumulatedrelease could reach about90%in6h.④The results showed that the qualitativeidentification of Longxuejie Colon-target Tablets was positive and spots were clear. Theresults of quantitative identification displayed that content of Loureirin B in LongxuejieColon-target Tablets was not less than0.6mg per tablet.⑤The initial stabilityinvestigation demonstrated that the stability of Longxuejie Colon-target Tablets wasqualified.Conclusions:①Via the investigation, the best prescription of core and coating wereoptimized. The preparation process was simply, feasible and repeatable. Every examinationcould reach the relevant standards of preparation.②Establishing the quality standard ofLongxuejie Colon-target Tablets and the operation methods were convenience, reproducible and accurate.③The initial stability investigation displayed that the quality of LongxuejieColon-target Tablets was stable, so the valid of preparation could initially determined in2years.