Printable-Microencapsulated Ascorbic Acid for Personalized Topical Delivery

Abstract

This study presents the successful development of printable-microencapsulated ascorbic acid (AA) for personalized topical delivery using laser printing technology. Rice flour with a 10% AA content was selected as an encapsulation material. Hydrophobic nanosilica was used to create negative electrostatic charges on the microencapsulated surfaces via a high-speed mixture. This process facilitated the microencapsulated AA fabrication using a commercial laser printer and produced a well-patterned design with some minor print defects, such as banding and scattering. The amount of encapsulated AA per area was 0.28 mg/cm², and the RGB color code was 0,0,0. An emulsion carrier system comprising pentylene glycol (P5G) or diethylene glycol monoethyl ether (DEGEE), Tween 20, oleic acid, and deionized (DI) water at a ratio of 20:30:30:20 was developed to enhance AA transmission into the skin. The Franz diffusion cell technique was used to investigate topical absorption on Strat-M membranes using P5G and DEGEE as enhancers. The steady-state fluxes were 8.40 (±0.64) and 10.04 (±0.58) μg/h/cm² for P5G and DEGEE, respectively. Cytotoxicity tests conducted on fibroblast cells revealed low cytotoxicity for the encapsulation products and carriers.

Keywords: ascorbic acid; laser printer; personalized topical delivery; printable microencapsulation; transdermal delivery.

Figure 1

Schematic view for fabrication of printable-microencapsulated ascorbic acids and carrier emulsion systems.

Figure 2

FTIR spectra of dry-milled rice flour (R), l-ascorbic acid powders (AA), hydrophobic silica (AEROSIL R202), 10% AA encapsulated in rice granules (10C-R), and 10C-R treated with 1% hydrophobic silica (1R202-10C-R): (a) 500–4000 cm^–1, (b) 960 cm^–1, and (c) XRD patterns of R, AA, and 10C-R.

Figure 3

SEM morphologies of (a) R, (b) AA powders, (c) 10C-R (outside and cross section), (d) 10C-R treated with silica (outside and cross section), (e) XR202-10C-R treated with silica 1, 3, 5%, (f) printable encapsulated AA in this study, and (g) commercial toner.

Figure 4

(a) Picture of an original artwork (.pdf), (b) picture of printed artwork, (c) defect in banding, and (d) defect in the background.

Figure 5

Cytotoxicity in fibroblast cells (a) in carrier solution T17 and P17 and (b) 10C-R and 5R812S-10C-R. Data are expressed as mean ± SD (n = 3). *p < 0.05, **p < 0.01, and ***p < 0.001.

Figure 6

Biocompatibility in fibroblast cells of 5R812S-10C-R, T17, and P17. Data are expressed as mean ± SD (n = 4). *p < 0.05, **p < 0.01, and ***p < 0.001.