Menthol/cyclodextrin inclusion complex nanofibers: Enhanced water-solubility and high-temperature stability of menthol

Abstract

Cyclodextrins are capable of forming non-covalent host-guest inclusion complexation with variety of molecules in order to enhance water-solubility and thermal stability of such hydrophobic and volatile molecules. Menthol, an efficient antibacterial and flavour/fragrance agent, is used in various applications like food, pharmacy, cosmetics, however, its low water-solubility and high volatility somewhat limit its application. In this study, menthol/cyclodextrin-inclusion complex (menthol/CD-IC) was formed in highly concentrated aqueous solution by using hydroxypropyl-b-cyclodextrin (HPbCD) and hydroxypropyl-g-cyclodextrin (HPgCD). The phase solubility studies and computational modeling studies revealed that menthol and these two CDs (HPbCD and HPgCD) formed stable inclusion complexes with the optimal molar ratio of 1:1 (menthol:CD) and inclusion complex formation enhanced the watersolubility of menthol. The electrospinning of nanofibers (NFs) from highly concentrated aqueous solutions (160%, w/v) of menthol/CD-IC was successfully performed without using additional fiber forming polymer and bead-free and uniform menthol/CD-IC NFs in the form of self-standing and flexible nanofibrous webs were produced. The initial molar ratio (1:1, menthol:CD) of the menthol/CD-IC in the solutions was mostly preserved in the menthol/CD-IC NFs (above 0.70:1.00, menthol:CD). The watersolubility of menthol was enhanced and menthol/CD-IC NFs have shown fast-dissolving character. The slow-release of menthol was achieved for menthol/CD-IC NFs, and the evaporation of menthol was shifted to much higher temperature (up to 275 C) for menthol/CD-IC NFs which proved the hightemperature stability for menthol due to inclusion complexation.

Fast-dissolving carvacrol/cyclodextrin inclusion complex electrospun fibers with enhanced thermal stability, water solubility, and antioxidant activity

“…To reveal the mechanism of inclusion complex, ab initio calculations based on density functional J Mater Sci (2018) 53:15837-15849 theory were done according to our previous studies [21,23].…”

“…Nonetheless, in our previous studies, uniform fibers from cyclodextrins have been successfully electrospun since cyclodextrin molecules can form aggregates via intermolecular hydrogen bonding in their highly concentrated solutions which results in formation of continuous jet without breaking up [11,12]. Moreover, in our recent studies, it has been shown that the fabrication of functional fibers from cyclodextrin inclusion complexes (CD-IC) with food additives and antibacterial substances is also possible [13][14][15][16][17][18][19][20][21][22][23][24].…”

Molecular Encapsulation of Cinnamaldehyde within Cyclodextrin Inclusion Complex Electrospun Nanofibers: Fast-Dissolution, Enhanced Water Solubility, High Temperature Stability, and Antibacterial Activity of Cinnamaldehyde

“…The presence of such CD aggregates prevents the breakage of the jet during electrospinning, and therefore bead-free uniform NFs can be electrospun from pure CD. 17−19 Furthermore, electrospun NFs from a variety of CD-ICs with food flavors and essential oils such as vanillin, 20 vitamin E, 21 eugenol, 22 menthol, 23 thymol, 24 and carvacrol 25 were also produced successfully.…”

Agrobiological Interactions of Essential Oils of Two Menthol Mints: Mentha piperita and Mentha arvensis

“…The applicability of encapsulation to MPEO was previously researched with maltodextrin [127], modified starches [128,129], and gelatin/gum Arabic [130] as core materials. Additionally, menthol was encapsulated in cyclodextrin [131]. It was shown that encapsulation was effective for retaining of PMEO and its sustaining release [128][129][130].…”