Gelatin/Chitosan Bilayer Patches Loaded with Cortex Phellodendron amurense/Centella asiatica Extracts for Anti-Acne Application

Abstract

Acne is a chronic inflammatory skin disease that often occurs with anaerobic Propionibacterium acnes (P. acnes). Anti-acne patches, made of hydrocolloid or hydrogel, have become a popular way of topical treatment. The outer water-impermeable layer of commercial patches might create hypoxic conditions and promote P. acnes growth. In this study, gelatin/chitosan (GC) bilayer patches were prepared at different temperatures that included room temperature (RT), −20 °C/RT, and −80 °C/RT. The most promising GC bilayer patch (−80 °C /RT) contained a dense upper layer for protection from bacteria and infection and a porous lower layer for absorbing pus and fluids from pimples. The anti-acne bilayer patch was loaded with Cortex Phellodendri amurensis (PA) and Centella asiatica (CA) extracts. PA extract could inhibit the growth of P. acnes and CA extract was reported to improve wound healing and reduce scar formation. Moreover, the water retention rate, weight loss rate, antibacterial activity, and in vitro cytotoxicity of the patches were investigated. The porous structure of the patches promoted water retention and contributed to absorbing the exudate when used on open acne wounds. The GC bilayer patches loaded with PA/CA extracts were demonstrated to inhibit the growth of P. acnes, and accelerate the skin fibroblast cell viability. Based on their activities and characteristics, the GC bilayer patches with PA/CA extract prepared at −80 °C/RT obtain the potential for the application of acne spot treatment.

Pharmacological Effects of Centella asiatica on Skin Diseases: Evidence and Possible Mechanisms

“…The methanol extract of C. asiatica was assayed for antibacterial activity using a disk diffusion assay [ 30 ]. The inhibition zones for the disks with 60 μ L of 15 mg/mL C. asiatica extract were <15 mm against P. acnes , indicating that the C. asiatica extract showed little antibacterial activity against P. acnes .…”

Herbal nanocosmecuticals: A review on cosmeceutical innovation

“…They used various ingredients such as talc, garlic, kaolin, nutmeg, gum Arabic, and titanium dioxide. 26 Recently, pigment from plant betalains is used in novel delivery for efficient lip care products. Similarly, colorant from the plant Bixa Orellana was used in lip jelly.…”

Patches for Acne Treatment: An Update on the Formulation and Stability Test

“…The function of the water-impermeable layer is that it can provide a protective layer and can help prevent the spread of pathogenic microorganisms, but this water-impermeable layer can create hypoxic conditions and increase the growth of P. acnes. This water-impermeable coating is not efficient at treating acne due to its protective function, so some medical-grade patches are required containing several substances such as benzoyl peroxide, salicylic acid, or chlorhexidine which can inhibit bacterial growth [14]. Based on the type of acne, acne patches are divided into several types (table 3).…”

“…Most of the anti-acne patches are hydrocolloid or hydrogel stickers which are waterproof on the surface to protect acne from secondary infection. The hydrocolloid patch can absorb fluid on the pimples and make the pimples flatten [14]. Hydrogel is a cross-linked hydrophilic polymer network with a high water content.…”