Experimental Study Of A PLA/INH Slow-Release Object Fabricated By Rapid Prototype Technology And Its Releasing Characteristic In Vitro

Objective: In this study, polylactic acid (PLA) is used as biodegradable drugloading matrix and to fabricate biodegradable INH/PLA tablet via3dimensionalprinting technology(3DP). Compare the drug release characteristic of three differentstructured tablet in vitro and determine the biocompatibility of the tablet.Method: PLA is prepared to be particles with diameter around75-100μm.Isoniazidbulk drug are dissolved into the organic dissolvant to be the binding liquid. Threedifferent drug delivery systems (columnar-shaped tablet、doughnut-shaped tablet andmultilayer doughnut-shaped tablet) are manufactured by the method of combiningPLA powders layer by layer with the three dimensional printing machine and loadedIsoniazid into the tablet. Compare the drug release characteristic of the three tabletsvia dynamic soaking method. MTT cytotoxicity test and Direct contact test are used tostudy the biocompatibility of the tablet. Observe the microstructure of the tablet’ssurface with electron microscope.Results: The PLA powder in the tablet can be excellently combined through3DPwithout disintegration. Electron microscope discover that INH distribute evenly onthe surface of the tablet in the nest-shaped way, while the surface of the barrier layerin the multilayer doughnut shaped tablet is compact and do not contain INH. Theconcentration of INH in all of the3tablets are still higher than the effectivebacteriostasis concentration (Isoniazid:0.025~0.05μg/ml) after30day’s releasing invitro. All of the tablets show initial burst release of the INH in the early period of thereleasing. Drug concentration of MDST become stable and just have little fluctationfrom the6thday of the releasing. Drug concentration of DST and CST decreasegradually and the decrease speed of DST is faster than CST. MTT cytotoxicity test and Direct contact test indicate that the tablet has rare cytotoxicity and favourablebiocompatibility.Conclusion:3DP is a reliable technique to fabricate complicated tablet. To compare thedrug releasing characteristic of the3structured tablet, MDST see the most stable drug release. It’san ideal drug delivery system for the antibiotic tablet. The multilayer donut-shaped tabletprovide a new method for the topical application of the antibiotic.