Proanthocyanidins from Vaccinium vitis-idaea L. Leaves: Perspectives in Wound Healing and Designing for Topical Delivery.

The compositions and health-beneficial properties of lingonberry leaves (Vaccinium vitis-idaea L.) are well established; however, their proanthocyanidins are still heavily underutilized. Optimizing their delivery systems is key to enabling their wider applications. The present study investigates the phytochemical and 'wound-healing' properties of proanthocyanidin-rich fraction(s) (PRF) from lingonberry leaves as well as the development of optimal dermal film as a proanthocyanidin delivery system. The obtained PRF was subjected to HPLC-PDA and DMAC analyses to confirm the qualitative and quantitative profiles of different polymerization-degree proanthocyanidins. A 'wound healing' in vitro assay was performed to assess the ability of PRF to modulate the wound environment for better healing. Low concentrations of lingonberry proanthocyanidins were found to accelerate 'wound' closures, while high levels inhibited human fibroblast migration. Fifteen dermal films containing PRF were prepared and evaluated based on their polymer (MC, HEC, PEG 400) compositions, and physical, mechanical, and biopharmaceutical properties using an experimental design. The composition containing 0.30 g of MC, 0.05 g of HEC, and 3.0 g of PEG 400 was selected as a promising formulation for PRF delivery and a potentially effective functional wound dressing material, supporting the need for further investigations.

Assessment of Physical, Mechanical, Biopharmaceutical Properties of Emulgels and Bigel Containing Ciclopirox Olamine.

Emulsions are thermodynamically unstable systems and it is difficult to produce biphasic formulations with large amounts of oil. The aim of our study was to prepare biphasic formulations containing 1% ciclopirox olamine and to determine the influence of the method of oil incorporation (without and with emulsifier and gelifier) on the physical (pH, particle size, rheological properties), mechanical, and biopharmaceutical properties of the formulations. It was found that the use of a poloxamer 407 gel as the hydrophase could result in a stable formulation when an oil with (EPG) or without an emulsifier (APG) or oleogel (OPG) was used as the oily phase. The results of the studies showed that the addition of an emulsifier (polysorbate 80) led to a decrease in the sol-gel temperature, a slower release of ciclopirox olamine, and a higher stability in the freeze-thaw test. However, regardless of the way the oil is incorporated, the particles are distributed in the same range and the antifungal activity against T. rubrum is the same. It is possible to create a biphasic formulation with a large amount of oil and poloxamer gel, but for greater stability, it is recommended to include an emulsifier in the composition.

Propolis - quality analysis and use in topical formulations.

The aim of this study was to produce propolis extracts, assess their quality and effect on skin cells and determine the penetration of active ingredients from designed semi-solid topical formulations. The use of higher-concentration ethanol and a larger amount of raw material allows extracting a larger quantity of active ingredients from raw propolis. Ultrasound extraction is an effective method for the production of aqueous extracts of propolis. The results show that depending on concentration, propolis extracts reduce the viability of keratinocytes. The phenolic compounds under observation penetrated the epidermis and dermis from designed formulations. The base of semi-solid formulation influences the efficacy of propolis preparations. The overall quantity of phenolic compounds that penetrated the skin was around 2 % from the ointment and 1.5 % from the cream.

Comparison of aqueous, polyethylene glycol-aqueous and ethanolic propolis extracts: antioxidant and mitochondria modulating properties.

BACKGROUND: Propolis is multicomponent substance collected by honeybees from various plants. It is known for numerous biological effects and is commonly used as ethanolic extract because most of active substances of propolis are ethanol-soluble. However, water-based propolis extracts could be applied more safely, as this solvent is more biocompatible. On the other hand, water extracts has significantly smaller range and quantity of active compounds. The extraction power of water could be enhanced by adding co-solvent which increases both solubility and penetration of propolis compounds. However, variation of solvents results in different composition of active substances that might have distinct effects. The majority of biological effects of propolis are attributed to the antioxidant properties of its active compounds. Antioxidant effect might be a result of either direct scavenging of ROS or modulation of ROS producing organelle activity. Therefore, the aim of this study was to investigate and compare chemical composition, antioxidant properties and effects on mitochondrial respiration of aqueous (AqEP), polyethylene glycol-aqueous (Pg-AqEP) and ethanolic (EEP) propolis extracts. METHODS: Chemical composition of propolis extracts was determined using HPLC and Folin-Ciocalteu method. Ability to neutralize H2O2 and intracellular ROS concentration in C6 glioma cells were determined fluorometrically by using 10-acetyl-3,7-dihydroxyphenoxazine and 2',7'-dichlorofluorescein diacetate, respectively. Mitochondrial superoxide generation was assessed under fluorescent microscope by using MitoSOX Red. Oxygen uptake rates of mitochondria were recorded by high-resolution respirometer Oxygraph-2 k. RESULTS: Our data revealed that phenolic acids and aldehydes make up 40-42% of all extracted and identified compounds in AqEP and Pg-AqEP and only 16% in EEP. All preparations revealed similar antioxidant activity in cell culture medium but Pg-AqEP and EEP demonstrated better mitochondrial superoxide and total intracellular ROS decreasing properties. At higher concentrations, AqEP and EEP inhibited mitochondrial respiration, but Pg-AqEP had concentration-dependent mitochondria-uncoupling effect. CONCLUSIONS: Aqueous and non-aqueous propolis extracts differ by composition, but all of them possess antioxidant properties and neutralize H2O2 in solution at similar efficiency. However, both Pg-AqEP and EEP were more effective in decreasing intracellular and intramitochondrial ROS compared to AqEP. At higher concentrations, these preparations affect mitochondrial functions and change energy production in C6 cells.

Formulation of Propolis Phenolic Acids Containing Microemulsions and Their Biopharmaceutical Characterization.

Microemulsions (MEs) were formulated using PEG-8 caprylic/capric glycerides and ethanolic propolis extracts. Characterization of MEs was performed by determining mean droplet size, polydispersity index, stability under varying external factors, and formulation effect on delivery of phenolic compounds into the skin ex vivo. Essential oils were included into the formulations of MEs and their influence on physical characteristics of the nanostructured systems as well as penetration into epidermis and dermis were evaluated. The droplet size, their distribution, and stability of the formulated MEs were not affected. Presence of essential oils in the formulation increased penetration of phenolic compounds in general, but only the amount of ferulic acid increased significantly. Mean droplet size increased with increase of oily phase amount, suggesting that phenolic compounds and components of essential oils were not modifying the formation of the interphase film composition and/or structure. Phenolic compounds were predominantly located in the lipid phase of the MEs thus minimizing their availability at the surface of the skin.

MODELING AND BIOPHARMACEUTICAL EVALUATION OF SEMISOLID SYSTEMS WITH ROSEMARY EXTRACT.

Scientific literature provides a great deal of studies supporting antioxidant effects of rosemary, protecting the body's cells against reactive oxygen species and their negative impact. Ethanol rosemary extracts were produced by maceration method. To assess biological activity of rosemary extracts, antioxidant and antimicrobial activity tests were performed. Antimicrobial activity tests revealed that G+ microorganisms are most sensitive to liquid rosemary extract, while G-microorganisms are most resistant to it. For the purposes of experimenting, five types of semisolid systems were modeled: hydrogel, oleogel, absorption-hydrophobic ointment, oil-in-water-type cream and water-in-oil-type cream, which contained rosemary extract as an active ingredient. Study results show that liquid rosemary extract was distributed evenly in the aqueous phase of water-in-oil-type system, forming the stable emulsion systems. The following research aim was chosen to evaluate the semisolid systems with rosemary exctract: to model semisolid preparations with liquid rosemary extract and determine the influence of excipients on their quality, and perform in vitro study of the release of active ingredients and antimicrobial activity. It was found that oil-in-water type gel-cream has antimicrobial activity against Staphylococcus epidermidis bacteria and Candida albicans fungus, while hydrogel affected only Candida albicans. According to the results of biopharmaceutical study, modeled semisolid systems with rosemary extract can be arranged in an ascending order of the release of phenolic compounds from the forms: water-in-oil-type cream < absorption-hydrophobic ointment < Pionier PLW oleogel < oil-in-water-type eucerin cream < hydrogel < oil-in-water-type gel-cream. Study results showed that oil-in-water-type gel-cream is the most suitable vehicle for liquid rosemary extract used as an active ingredient.

Formation and Biopharmaceutical Characterization of Electrospun PVP Mats with Propolis and Silver Nanoparticles for Fast Releasing Wound Dressing.

Antibacterial, antiviral, antifungal, antioxidant, anti-inflammatory, and anticancer activities of propolis and its ability to stimulate the immune system and promote wound healing make it a proper component for wound dressing materials. Silver nanoparticles are recognized to demonstrate strong antiseptic and antimicrobial activity; thus, it also could be considered in the development of products for wound healing. Combining propolis and silver nanoparticles can result in improved characteristics of products designed for wound healing and care. The aim of this study was to formulate electrospun fast dissolving mats for wound dressing containing propolis ethanolic extract and silver nanoparticles. Produced electrospun nano/microfiber mats were evaluated studying their structure, dissolution rate, release of propolis phenolic compounds and silver nanoparticles, and antimicrobial activity. Biopharmaceutical characterization of electrospun mats demonstrated fast release of propolis phenolic compounds and silver nanoparticles. Evaluation of antimicrobial activity on Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa, Proteus vulgaris, Bacillus subtilis, Bacillus cereus, and Candida albicans strains confirmed the ability of electrospun mats to inhibit the growth of the tested microorganisms.

Release of propolis phenolic acids from semisolid formulations and their penetration into the human skin in vitro.

Antioxidant and free radical scavenging effects are attributed to phenolic compounds present in propolis, and when delivered to the skin surface and following penetration into epidermis and dermis, they can contribute to skin protection from damaging action of free radicals that are formed under UV and premature skin aging. This study was designed to determine the penetration of phenolic acids and vanillin into the human skin in vitro from experimentally designed vehicles. Results of the study demonstrated the ability of propolis phenolic acids (vanillic, coumaric, caffeic, and ferulic acids) and vanillin to penetrate into skin epidermis and dermis. The rate of penetration and distribution is affected both by physicochemical characteristics of active substances and physical structure and chemical composition of semisolid vehicle. Vanillin and vanillic acid demonstrated relatively high penetration through epidermis into dermis where these compounds were concentrated, coumaric and ferulic acids were uniformly distributed between epidermis and dermis, and caffeic acid slowly penetrated into epidermis and was not determined in dermis. Further studies are deemed relevant for the development of semisolid topically applied systems designed for efficient delivery of propolis antioxidants into the skin.

[A study on release of propolis extract components from emulsion-type dispersions]. / Propolio ekstrakto komponentu atsipalaidavimo is emulsiniu dispersiju tyrimai.

BACKGROUND AND OBJECTIVE: Carrier development is one of the essential stages in the formulation of semisolid pharmaceutical dosage form for topical application. The stability of semisolid preparation during storage can be predicted from rheological testing. An adequate composition of semisolid preparation determines its stability and proper release of drug substance, and allows bypassing long-term heating and melting of the cream base components while incorporating complex extracts. Soft propolis extract, well known for its antimicrobial, antiviral, anti-inflammatory, and antioxidant effects, was chosen as a complex biologically active ingredient for the development of emulsion dispersion system. The aim of this study was to evaluate the impact of physical-chemical characteristics of the carrier on the release rate of biologically active ingredients from the modeled dosage form in vitro, thus justifying the relevance of the carrier composition and applied technologies. MATERIAL AND METHODS: Soft propolis extract (1%-3%) was incorporated into water-in-oil type emulsion. The quality of the model systems was evaluated referring to their viscosity, quantity of polyphenols and their rate of release from the preparation by applying an in vitro model. Quantitative determination of polyphenols was performed by spectrophotometry using a standard calibration curve of ferulic acid. RESULTS: The results showed that a stable homogeneous semisolid emulsion system containing soft propolis extract could be produced when the concentration of emulsifier was in the range of 3%-12%. The quantity of emulsifier had an impact on the viscosity of semisolid systems, but practically had no effect on the release rate of polyphenols from the cream matrix. The results also demonstrated that the added amount of soft propolis extract had a less significant effect than temperature of the system. CONCLUSION: It was confirmed that changes in the viscosity of emulsion dispersion systems had no effect on the stability of model dispersion systems when temperature was increased, and this has to be evaluated to determine the storage conditions of the model preparations.