Andrographis paniculata-loaded niosome for wound healing application: Characterisation and in vivo analyses

Andrographis paniculata (A. paniculata) is widely used as a topical treatment due to its medicinal properties, such as anti-inflammatory, antibacterial and collagen synthesis, which are essential for the wound healing process. Non-ionic surfactant vesicles or niosomes can increase the bioavailability of poorly water-soluble drugs through a biological membrane. Therefore, A. paniculata extract was loaded into the niosome, which acts as a nanocarrier to facilitate the active compound in the delivery system. A standard Soxhlet method was used to extract A. paniculata by using water or ethanol as a solvent. Both extracts were subjected to High Pressure Liquid Chromatography (HPLC), antioxidant activity and cell culture analysis to determine the best concentration for niosome encapsulation. Niosome was prepared by proniosome-derived niosomal dispersion and homogenized for size reduction. The resulted niosome was incorporated into carbopol gel and the wound healing efficacy was analysed in vivo to evaluate the macroscopic and histology of treated rats. Extraction of A. paniculata by ethanol shows higher andrographolide content (52 ppm) and antioxidant activity at 2.5 mg/mL. Entrapment efficiency (EE) showed that the formulation 1 (0.6 mmol Span60, 0.4 mmol Cholesterol, 0.1 mmol Labrasol) had the highest EE for water and ethanol extract by 97.75% ± 1.28 and 97.21% ± 1.89, respectively. The optimized concentration of 100 ppm was loaded into niosomal gel because it stimulates the proliferation and migration of human skin fibroblast cells. Wound treated by niosomal gel containing A. paniculata ethanol extracts exhibited total recovery by 100%. Prominent collagen fibres and formation hair follicle were observed at the end of 14 days. The present study demonstrates a beneficial effect of A. paniculata-loaded niosomal gel which effectively assist in the wound healing process and protects the tissue from oxidative stress.