Synthesis Of Drug-loaded Alginate Fiber And Its Release Behavior

With the rapid development of modern science and technology, especially in materialscience and chemical science, the application of textile technique in pharmaceutics would becontinued exploited. Then as a new type of dosage form, drug-loaded fiber was fabricated.Currently, the main preparation of drug-loaded fiber was finishing method and blend spinningmethod. Evern though the process of drug-loaded fiber by finishing method was simple, therelease behavior was not good. Besides, drug-loaded fiber by blend wet-spinning technology wasvery popular in many studies, while it would cause mass drug lost and lower drug-loaded ratio.In order to enhance the drug loading capacity of drug-loaded fiber, nano-capsules wereprepared by sodium alginate, and subsequently mixed with sodium alginate solution to obtainspinning dope. Then drug-loaded alginate fiber was produced by wet-spinning through calciumchloride solution. This study had examined the rheological properties and spinnability ofsodium alginate solution; investigated the effect of spinning dope concentration, coagulationbath concentration, coagulation bath temperature and draft ratios on the fiber morphology,structure and mechanical properties; fabricated nano-capsules drug-loaded alginate fiber underthe optimiality spinning conditions, and investigated the effect of capsule dosage, pH andtemperature on the drug release behavior of drug-loaded alginate fiber, and tested the fibermoisture absorption and gel-forming properties. Finally, the results were showed as follows:1) The rheological properties and spinnability of sodium alginate solution: Sodium alginatesolution was typical pseudoplastic fluid. And, with the increasing of concentration, thenon-Newtonian index (n) was gradually reduced, while the structural viscosity index (Δη) wasgradually increased, resulting to the reduced of sodium alginate liquidity. Finally, the suitableconcentration for wet-spinning was obtained:0.5-4.5%.2) Fabricated alginate fiber and obtained optimal spinning parameters: System investigatedthe effect of spinning dope concentration, coagulation bath concentration, coagulation bathtemperature and draft ratios on the morphology, structure and mechanical properties of alginatefiber, and obtained the optimal spinning parameters: spinning dope concentration was3.5%,coagulation bath concentration was2.5%, coagulation bath temperture was30℃, and draft ratio was1.5. At this time, alginate fiber showed good morphology, and obtained max mechanicalproperties (tensile strength of18.90±0.90cN/tex, elongation at break of8.83±0.35%,respectively). Besides, with the increasing of draft ratios, the regularity of molecular chains wasgradually enhanced, and resulting to the better fiber orientation and crystallization.3) Fabricated and characterized drug-loaded alginate fiber: Calcium alginate nano-capsuleswere produced as methylene blue as drug model, and the max drug loaded ratio was70.1±1.3%.Drug-loaded alginate fiber was successfully wet-spun by mixing nano-capsules with sodiumalginate solution. Nano-capsules could be evenly present on the fiber surface and internal, andwould not significantly affect the fiber structure and mechanical properties. The drug capacity ofdrug-loaded alginate fiber by this method was two times than traditional drug-loaded fiber.Besides, it had confirmed that this preparation could effectively reduce the drug wastage in thespinning process, and improve the drug loaded ratio. Apart from this, drug-loaded alginate fibershowed more prominent sustained release function in vitro drug release. The moisture absorptionand gel-forming properties were also tested, and the results showed that the maximum waterabsorption was25.17g/g, and gelated just need4min, which had confirmed the possibility ofdrug-loaded alginate fiber as medical dressing.