Design, Preparation, and Physicochemical Characterisation of Alginate-Based Honey-Loaded Topical Formulations

Abstract

Honey has widespread use as a nutritional supplement and flavouring agent. Its diverse bioactivities, including antioxidant, antimicrobial, antidiabetic, anti-inflammatory, and anticancer properties, have also made it an aspirant natural product for therapeutic applications. Honey is highly viscous and very sticky, and its acceptance as a medicinal product will require formulation into products that are not only effective but also convenient for consumers to use. This study presents the design, preparation, and physicochemical characterisation of three types of alginate-based topical formulations incorporating a honey. The honeys applied were from Western Australia, comprising a Jarrah honey, two types of Manuka honeys, and a Coastal Peppermint honey. A New Zealand Manuka honey served as comparator honey. The three formulations were a pre-gel solution consisting of 2–3% (w/v) sodium alginate solution with 70% (w/v) honey, as well as a wet sheet and a dry sheet. The latter two formulations were obtained by further processing the respective pre-gel solutions. Physical properties of the different honey-loaded pre-gel solutions (i.e., pH, colour profile, moisture content, spreadability, and viscosity), wet sheets (i.e., dimension, morphology, and tensile strength) and dry sheets (i.e., dimension, morphology, tensile strength, and swelling index) were determined. High-Performance Thin-Layer Chromatography was applied to analyse selected non-sugar honey constituents to assess the impacts of formulation on the honey chemical composition. This study demonstrates that, irrespective of the honey type utilised, the developed manufacturing techniques yielded topical formulations with high honey content while preserving the integrity of the honey constituents. A storage stability study was conducted on formulations containing the WA Jarrah or Manuka 2 honey. The samples, appropriately packaged and stored over 6 months at 5, 30, and 40 °C, were shown to retain all physical characteristics with no loss of integrity of the monitored honey constituents.

Determination of Physicochemical Characteristics, Phytochemical Profile and Antioxidant Activity of Various Clover Honeys

“…The pH values of all clover honeys this study investigated (Table 1) were slightly more acidic than the majority of the investigated WA honeys, which had a mean pH of 4.56, ranging from 3.86 to 5.69 [14] . A slightly higher water content was also detected in the investigated clover honeys compared to the majority of the WA reference honeys, which ranged in moisture content from 14.05 to 26 %, with a mean of 17.47 % [14–16] …”

“…After developing the HPTLC plates in two different mobile phases of varying polarities (Mobile Phases A and B), the plates were derivatised with DPPH reagent which allowed to specifically capture antioxidant bands. Their DPPH radical scavenging activity was then calculated based on the band's respective colour by converting its RGB value (generated automatically by the HPTLC software) into a corresponding hue value [15] . The obtained hue value was used to express the level of scavenging activity in relation to that of gallic acid, which is the standard reference compound to express total antioxidant activity in the FRAP assay (Table 5 and Table 6).…”

“…Moisture content was determined as described by Hossain et al [39] . Briefly, 100 mg honey samples were placed on the sample well of a Refractometer (HI96801, Hanna Instruments, Smithfield, RI, USA), readings were taken in triplicate and the result expressed as a percentage (w/w) [15] …”

Application of a Customised Franz-Type Cell Coupled with HPTLC to Monitor the Timed Release of Bioactive Components in Complex Honey Matrices

“…Honey-based formulations were prepared according to a previously published protocol [ 13 ]. The honeys used in this study were two Western Australian (WA) Manuka honeys ( Leptospermum sp.…”

“…A solution of 4,5,7-trihydroxyflavanone in methanol was prepared (0.5 mg/mL) and used as a reference solution for HPTLC analysis. The respective baseline samples for all honeys and their corresponding formulations (t = 0 min) were prepared as follows: 200 mg pure honey/honey-loaded formulations were dissolved in 1 mL of deionised water followed by three extractions with 5 mL each of a mixture of dichloromethane and acetonitrile (50:50 v / v ) [ 13 ]. The extraction efficiency for this approach was determined by spiking artificial honey (made from 1.5 g sucrose, 7.5 g maltose, 40.5 g fructose, and 33.5 g glucose in 17 mL of sterile distilled water) [ 14 ] with 0.3 mg of 4,5,7-trihydroxyflavanone and was found to be 99.55%.…”