Preparation Of Polymer Materials With Amphiphilic Properties In Transdermal Drug Delivery Systems

Styrene-isoprene-styrene block copolymer (SIS), as pressure-sensitive adhesives, has the advantage of strong cohesion and higher drug loading.However, its application in transdermal drug delivery systems(TDDS) is limited by its strong hydrophobicity.To solve this problem, chemical grafting is used to improve the hydrophilicity of SIS, as the basis for preparation of amphiphilic HMPSA.Adopt the method of grafting side chains on the SIS, amphiphilic polymers was prepared with clear structure and polarity of regulation. In the grafting reaction, amount of grafted side chain can be controlled accurately by the epoxy degrees of ESIS, length of grafted side chain can be controlled accurately by selecting different macromolecular nucleophilic reagent.First of all, the SIS was epoxydized (ESIS), studied the effect of temperature, time, dosage of formic acid and hydrogen peroxide on the reaction. ESIS with different epoxy degrees was prepared by controlling the dosage of hydrogen peroxide.On the basis of epoxidation reaction, ESIS with a certain epoxy degree was used for open loop grafting.Non-ionic surfactants containing hydroxyl-nonylphenol polyoxyethylene ether (NP-40) reacted with potassium hydroxide (KOH), alcohol potassium (t-BuOK) was prepared. Then epoxy groups were opened by ring opening reaction with the macromolecular alcohol potassium as nucleophilic reagent.At the same time with ring opening reaction, polyoxyethylene ether chain also grafted onto SIS, and achieved the goal of grafting hydrophilic side chain. In the grafting reaction. ESIS’s ring opening rate can reach100%. To explore the best conditions of reaction, studied the effect of temperature, time, solvent and the dosage of reagents on the reaction. Under the optimum reaction conditions, octyl phenol polyoxyethylene ether (OP-10) and fatty alcohol polyoxyethylene ether (Peregal O-25) were used in the grafting reaction, ESIS’s ring opening rate both can reach100%. Fourier transform infrared spectroscopy (FT-IR),hydrogen nuclear magnetic resonance (JHNMR), gel permeation chromatography (GPC), differential scanning calorimetry(DSC) and thermo-gravimetric analysis(TGA) were used to characterize the reaction products.On the basis of laboratory research, the epoxidation rection of SIS and ring opening reaction of ESIS were amplified. The experimental results as follow:ESIS of epoxidation amplification experiment have higher epoxy degrees compared with laboratory results; ring opening reactionof ESIS has good repeatability, but need to improve the reaction equipment.Amphiphilic hot melt pressure sensitive adhesive is prepared with GSIS as matrix. Different viscosity resin impact on the properties of hot melt pressure sensitive adhesive drug release was researched. The results show that with hydrophilic hydrogenated rosin as visco-sity-enhancing resin,24h cumulative release rate of geniposide was obviously higher than C5resin.Hydrogenated rosin was used as viscosity-enhancing resin in GSIS hot melt pressure sensitive adhesive, and its release properties and adhesion properties were characterized.The experimenttal results show that:through the graft modification of SIS, the24h cumulative release rate of hydrophilic drug geniposide is increased, and homogeneously slow-release state.