Preliminary Evaluation On Preparation Of Vaginal Delivery Vector Based On Natural Spider Silk Protein

Objective: Vaginal mucosa administration has significant advantages in the treatment of vaginitis,cervicitis and other related diseases.The existing vaginal drug dosage forms are lotion,tablet,suppository,gel and so on.The purpose of sustained release cannot be achieved during use.Multiple dosing is required to compensate for the deficiencies of the above preparations.In this paper,spider silk protein was used to develop a delivery carrier for vaginal sustained release of drugs,in order to achieve the purpose of vaginal sustained release of drugs.Methods: Firstly,taking the solubility of spider silk as index,orthogonal experimental design was carried out on the dissolution temperature,dissolution time and material ratio,and the optimal parameter combination of spider silk dissolution was obtained at the preset level.Taking slow-release property as the index,Box-Behnken Design response surface method was used.Structure evaluation(scanning electron microscopy,Fourier infrared,X-ray diffraction),quality evaluation(solvent residue,static water contact Angle,water vapor transmittance,swelling degree,etc.),and safety evaluation(in vitro cytotoxicity test,vaginal mucosa irritation test)were carried out for the preparation of drug delivery carrier.Finally,metronidazole and Periplaneta Americana extract were used as model drugs to evaluate the application of drugs to evaluate the application of drugdelivery carriers,focusing on the slow release property of drug delivery carrier loaded with different components in artificial vaginal fluid.Results:(1)The dissolution conditions of spider silk were screened with the yield of spider silk protein as the index.Hexafluoro-isopropyl alcohol was used as the solvent and the material ratio was 1:1(mg:m L).The optimal solution parameter was stirred at 60 ℃ for 8 h.(2)The solution concentration,film forming temperature and feeding ratio per unit area were optimized by Box-Behnken Design response surface model.The optimal film forming conditions for slow release property were as follows: spider silk protein solution concentration of 5 mg/m L,film forming temperature of 40 ℃,and feeding amount per unit volume of 600 mg.(3)The evaluation of the structure of drug delivery carrier showed that the drug delivery carrier prepared by the method of this subject has a three-dimensional porous structure,which is conducive to drug load;And the prepared drug delivery carrier is a stable silk Ⅱ structure,suitable for drug delivery.(4)The quality evaluation results of drug delivery carrier showed that the solvent residue of drug delivery carrier prepared by the method of this subject was within the safe range,the carrier had good hydrophilicity and good adhesion potential.Suitable for mucosal administration,its swelling degree is low,applied to the vaginal environment will not cause discomfort due to excessive swelling.(5)The safety evaluation results of drug delivery vector: The cytotoxicity test of L-929 cells showed that the relative growth rate of both the blank film group and the drug-loaded film group was greater than 70%,indicating that spider silk protein film prepared by this method should not have significant cytotoxicity.The vaginal mucosal stimulation experiments on SD rats showed that the spider silk protein film prepared by this experimental method had very mild vaginal stimulation on SD rats.(6)Metronidazole and Chinesse herbal medicine Periplaneta Americana extract were used as model drugs.Vaginal sustained-release film was prepared in artificial vaginal fluid according to the experimental method of this subject.The fitting of drug release equation belonged to Higuich equation.And sustained release time can be up to 20 days.Conclusions: In this paper,the preparation conditions of spider silk film-forming were optimized step by step to obtain the optimal conditions for the preparation of slow-release vaginal mucosal drug delivery carriers.Chemical monomer-metronidazole and Chinease medicine-Periplaneta Americana extract were selected as model drugs,which have excellent slow-release property in artificial vaginal fluid.The slow release behavior of the vaginal slow-release film agents loaded on the delivery carrier was fitted.The slow-release behavior of the vaginal slow-release film agents belonged to the Higuchi equation.The drug delivery vector has good safety in both cell and animal level.