Electrospun cellulose acetate fiber mats containing asiaticoside or Centella asiatica crude extract and the release characteristics of asiaticoside

Ultra-fine cellulose acetate (CA; Mw ≈ 30,000 Da; degree of acetyl substitution ≈ 2.4) fiber mats containing asiaticoside (AC) from the plant Centella asiatica L. either in the form of pure substance (PAC) or a crude extract (CACE) were fabricated by electrospinning. Incorporation of either PAC or CACE (40 wt.% based on the weight of CA) in the neat CA solution (17% w/v in 2:1 v/v acetone/dimethylacetamide) did not affect the morphology of the obtained fibers, as both the neat and the herb-loaded CA fibers were smooth. The average diameters of these fibers ranged between 301 and 545 nm. Determination of the release characteristics of AC from the herb-loaded CA fiber mats was carried out by the total immersion and the transdermal diffusion through a pigskin method in acetate or phosphate buffer solution that contained methanol (hereafter, A/B/M or P/B/M medium) at either 32 or 37 °C, respectively. In the total immersion method, the maximum amounts of the AC released from the PAC- and the CACE-loaded CA fiber mats into the A/B/M medium were ∼24 and ∼10% (based on the weight of the specimens), while those of the AC released into the P/B/M medium were ∼26 and ∼12%, respectively. Considerably lower values were, however, obtained when the materials were placed on top of a piece of pigskin. Lastly, the herb-loaded CA fiber mats released no substance that was harmful to normal human dermal fibroblasts, rending their potential for use as topical/transdermal or wound dressing patches.