(181ac) Aqueous Media Resistant PVA/HPMC Nanofibers By Electrospinning Technique for Drug Delivery System

Poly (vinyl alcohol) (PVA) and hydroxypropyl methylcellulose (HPMC) are potential candidates to be used as drug carriers due to their biosafety, inertness and stability. In addition, the combination of both in a layered material, would allow to prepare a material with a convenient porosity, high surface area, and with the possibility of controlling the shape and size pore. However, in order to develop their use as drug delivery system it is necessary to prepare materials stable under physiological media. Since both polymers are water-soluble, is necessary the development of a synthesis strategy to make it resistant in aqueous solution, which has been the main objective of present work.

With this aim, a novel layered material combining PVA and HPMC containing amoxicillin has been prepared. To optimize its later use in implants and oral surgery, it was opted for its preparation in the form of nanofiber using the electrospinning technique. In order to confer its stability under aqueous media, it has been evaluated a cross-linking method using glutaraldehyde (GA).

Layered samples (not cross-linked and cross-linked) were prepared and characterized, as well as the pure materials (PVA, HPMC, GA and amoxicillin) for their comparation. Scanning electron microscope (SEM) images confirm the stability and the morphology of the nanofibers once the layered sample, after cross-linking process, is immersed in an aqueous solution. However, the layered sample, which was not cross-lined, loses its nanofiber morphology, becomes a gelatinous material and finally, dissolved.

Furthermore, Fourier-transform infrared spectroscopy (FTIR) and thermal-gravimetry analyses (TGA) show the contribution of the pure materials in the layered sample (cross-linked). For the release tests, a buffer solution simulating saliva (with a pH of 6.8 and at 37 °C) is used. The results show a controlled release using the layered sample (cross-linked).

In conclusion, the layered sample prepared and treated by a cross-linking process, shows successful results, remaining its nanofiber morphology and being it a stable material for its purpose.