Design and Characterization of Sodium Alginate and Poly(vinyl) Alcohol Hydrogels for Enhanced Skin Delivery of Quercetin

Abstract

Nature has led to the discovery of biopolymers with noteworthy pharmaceutical applications. Blended biopolymers have demonstrated promising characteristics when compared with their individual counterparts. Sodium alginate (SA) is a marine polymer that has demonstrated the ability to form hydrogels, an interesting property for the development of cutaneous formulations. Predicting the good performance of blended biopolymers, a novel series of hybrid hydrogels based on SA and poly(vinyl) alcohol (PVA) were prepared. Quercetin, a natural polyphenolic flavonoid commonly found in fruits and vegetables, is widely known for its strong anti-inflammatory and antioxidant activity, thus with potential applications against melanoma, dermatitis, psoriasis, and skin ageing. Here, hydrogels were produced at different ratios of SA and PVA. The surface morphology, structure, interaction of polymers, the capacity to absorb water and the entrapment efficiency of quercetin were evaluated for the blended hydrogels. Targeting the cutaneous application of the formulations, the rheological properties of all unloaded and quercetin-loaded hydrogels revealed pseudoplastic behavior, evidence of non-thixotropy, good resistance to deformation, and profile maintenance with temperatures ranging from 20 °C up to 40 °C. The incorporation of quercetin in the hydrogel retained its antioxidant activity, confirmed by radical scavenging assays (ABTS and DPPH). The permeability of quercetin through the skin showed different penetration/permeation profiles according to the hydrogel’s blend. This behavior will allow the selection of SA-PVA at 2/1 ratio for a local and prolonged skin effect, making the use of these hydrogels a good solution to consider for the treatment of skin ageing and inflammation.

The Rediscovery of Honey for Skin Repair: Recent Advances in Mechanisms for Honey-Mediated Wound Healing and Scaffolded Application Techniques

“…Lastly, particular attention should be given to the possible interactions between the compound of interest and the hydrogel components, other active agents, and excipients, and how these can affect the pharmacokinetic aspects of the active principle, for example by modulation of its release. For instance, it is worth mentioning that the incorporation of polyphenols within a scaffold or delivery system might restrict their antioxidant potential, as shown by a diminished responsiveness to radical scavenging tests such as ABTS and DPPH of different quercetin-hydrogel formulations compared to the free flavanol [173]. In addition, no statistical difference in antibacterial potency was observed between Manuka honey samples with different UMF when these were loaded into scaffolds for medical engineering, despite a significantly different bacterial inhibition being obtained with direct application of the same honeys [92].…”

Synthesis of Biomaterial-Based Hydrogels Reinforced with Cellulose Nanocrystals for Biomedical Applications

“…The viscosity of a shear thinning liquid has an inversely proportional relationship with the shear rate, whereas a shear thickening liquid has a directly proportional relationship between viscosity and the shear rate [37]. Pseudoplastic nature is important for topical formulations that have viscous behaviour under static conditions; nevertheless, this viscous behaviour tends to decrease at a higher shear rate which results in better spreadability and improves the drug permeation of specific substances upon topical application [11]. By the reinforcement of CNC to hydrogels, the viscosity vs. shear rate curve of CNC-ALG-GEL and CNC-CHI-GEL hydrogels has transformed to a plateau shape, due to the breaking down of CNC domains by shearing force [38].…”

“…Many researchers have developed biopolymer-based materials such as hydrogels and scaffolds for wound dressing, biomedical applications, and therapeutic research. Several research studies have been extensively made for the incorporation/fabrication/injection of CNC into biopolymers such as alginate, chitosan, gelatin, polyvinyl alcohol, and hydroxyapatite [2,5,[8][9][10][11]. Jeddi and Mahkam synthesized nanocarboxymethyl cellulose from CNC to incorporate in bilayer alginate-chitosan hydrogel beads and successfully use as a carrier for the controlled delivery of dexamethasone [12].…”

Non-Invasive Drug Delivery Systems

“…Non-invasive drug delivery research is an active, rich and multidisciplinary research area and this Special Issue aims to present the current state of the art in the field. The contributions in this Special Issue address drug delivery systems for administration through the oral route [ 1 , 2 , 3 , 4 ], respiratory administration [ 5 , 6 ], nose-to-brain delivery [ 7 ] and via the skin [ 8 , 9 , 10 , 11 , 12 , 13 , 14 ]. Furthermore, a broad range of drug delivery systems and therapeutics (both small drug molecules and biologics) for non-invasive delivery were investigated and discussed, including nanosystems such as silica nanoparticles [ 15 ].…”

“…Articles focusing on delivery via the skin report a range of delivery systems. This includes sodium alginate and poly(vinyl) alcohol hydrogels for enhanced skin delivery of quercetin (a natural polyphenolic flavonoid commonly found in fruits and vegetables and known for anti-inflammatory and antioxidant effects) as an example system that could be considered as an option for the treatment of skin ageing and inflammation [ 8 ]. Microneedle-based systems for administration of local anaesthesia (lidocaine) are reported by Yang et al [ 9 ], confirming the delivery of clinically-relevant levels of lidocaine and a fast onset time.…”