Study On Preparation Of Eye Collagen Membrane And Drug Carrier Release

Eye drops and ointment are mainly used in the clinical application of eye diseases.Eye drops after treatment would be of tolerability and low bioavailability because erosion or loss from the nasolacrimal duct tear,and be administered frequently.Due to the inconvenient administration at night,pharmacological peak-to-valley phenomenon is obvious.Matrix because of its transparency and the refractive index of the factors in the ointment can also cause blurry vision.Ophthalmic collagen membrane may improve the bioavailability of the eye and sustain and control release drug delivery and to achieve effective therapeutic concentration of the drug within the eye and maintain a certain amount of time.The pig sclera sources were done by acid crude extract and with the ion exchange column chromatography and type Ⅰ collagen of acid-soluble collagen was obtained.The research results show that the optimized conditions of acid extraction of collagen:peel a good pig eye with 1 mol·L-1 sodium chloride,0.05 mol·L-1 Tris-HCl(pH 7.2)buffer(containing N-homogenate ethylmaleimide,phenylmethylsulfonyl fluoride,Na2EDTA,and 6-amino hexanoic acid from 4 protease inhibitor)4℃,stirring extraction 24 h,16000 rpm centrifugation 1 h.Precipitate with 0.5 mol-L-1 titanium suspension was dissolved,24 h,16000 rpm centrifugation 1 h same stirring extraction.Merge the two supernatants,and add then sodium chloride to 4.5 mol L-1 salting preliminarily purified collagen,0.5 mol·L-1 acetic acid was dissolved precipitate with Millipore ultrafiltration unit,using ion exchange chromatography,the purified collagen,the first SP cation chromatography column purified collagen,the eluate collected by SDS-PAGE electrophoretic analysis confirmed that the eluate is the purified collagen,and then the eluate was dealt with Q anion chromatography and re-distribution of the protein in the collected flow-through.The final lyophilized collagen powder was compared with control standard type I collagen protein by SDS-PAGE to do electrophoresis analysis and to confirm whether it was the ideal collagen protein.Eye collagen membrane was prepared with solvent evaporation method,and effects of preparation conditions on the film-forming properties,ideal film-forming conditions were studied:the film-forming base plate is made of PVC mold;collagen solution concentration is 30 mg · ml-1 titanium concentration 0.5 mol·L-1;glutaraldehyde solution concentration 0.25%;20℃ under vacuum to dry.The obtained collagen membrane was transparent,with the curvature of 9 mm,and a diameter of 14 mm.It has a good moisture absorption,softness,elasticity and tensile.Their drug absorption rate,drug insutance rate,light transmittance and degradation time were tested.And the result showed,the rate of drug absorption of the collagen membrane and drug insutance rate and commodity collagen membrane undifferentiated translucent were superior to commodity collagen film.In PBS solution with at 37℃ 100 U collagenase,the collagen membrane in 3 h may be completely degraded.Levofloxacin was used as a model drug.Two different drug-loaded manner collagen membrane were prepared,a non-collagen membrane levofloxacin immersion approach,absorption of the drug solution;collagen membrane with added levofloxacin.And then in vitro drug release,the cumulative release,release percentage were tested.These two collagen membranes were added to pH 7.4,5 ml PBS buffer solution at 37℃temperature oscillation in vitro release test.At regular intervals 1ml release of liquid was removed,measuring the absorbance,while 1 ml of phosphate buffer solution was added.The experimental results show that the collagen membrane prepared dosing release effect.Levofloxacin was applied as a model drug in vivo tests.Using the HPLC determination,with the two different drug loading modes of collagen membrane,the drug concentration of the aqueous humor in the rabbit eye was observed,and compared with the levofloxacin instillation drug solution.The absorption of the drug by the collagen membrane impregnated collagen membrane levofloxacin in the rabbit eye and eliminated the linear dynamic characteristics.Instillation compared with levofloxacin collagen membrane showed significantly slow-release effect,and comparing the drug-loaded collagen membrane with impregnated collagen membrane the sustained-release effect of the former collagen membran is much more obvious.In this study,collagen was extracted by ion exchange chromatography,and verified by SDS-PAGE electrophoresis collagen I.Select PVC backplane mold material,the use of collagen membrane solvent evaporation method to the preparation of type I collagen,and study their performance and drug release characteristics.The results showed that the prepared collagen membrane was translucent,biodegradable.Levofloxacin as a model drug was used to test the collagen membrane preparation process dosing long time in the release,the release amount is more than soaking dosing collagen membrane,sustained-release effect.Collagen type I,according to the characteristics of eye physiological structure made of a certain spherical,a radius of curvature,the collagen membrane of a certain thickness,can absorb,store and slow release of drugs,increase penetration of the drug,enhance the bioavailability of the drug.Collagen membrane has good tissue compatibility and biodegradability of support to promote the growth of corneal epithelial cells,while promoting the healing of the wound.It can be used to treat certain eye diseases,and therefore can be used as a new formulation for ocular administration.