Helena Ribeiro - Academia.edu (original) (raw)
Papers by Helena Ribeiro
Pharmaceuticals, 2022
The use of natural products in dermatology is increasingly being pursued due to sustainability an... more The use of natural products in dermatology is increasingly being pursued due to sustainability and ecological issues, and as a possible way to improve the therapeutic outcome of chronic skin diseases, relieving the burden for both patients and healthcare systems. The legalization of cannabis by a growing number of countries has opened the way for researching the use of cannabinoids in therapeutic topical formulations. Cannabinoids are a diverse class of pharmacologically active compounds produced by Cannabis sativa (phytocannabinoids) and similar molecules (endocannabinoids, synthetic cannabinoids). Humans possess an endocannabinoid system involved in the regulation of several physiological processes, which includes naturally-produced endocannabinoids, and proteins involved in their transport, synthesis and degradation. The modulation of the endocannabinoid system is a promising therapeutic target for multiple diseases, including vascular, mental and neurodegenerative disorders. How...
Nanocarriers for Drug Delivery, 2021
Micro-and nanoemulsions are disperse systems widely used for the efficient and targeted drug deli... more Micro-and nanoemulsions are disperse systems widely used for the efficient and targeted drug delivery through various routes of administration. The difference between micro-and nanoemulsions is not related to the size scale, as the names suggest, since both systems might contain droplets with a diameter lower than 100 nm. The main difference between these two systems is that the droplet size of nanoemulsions is obtained by a mechanical reducing method, while microemulsions are formed spontaneously. Thus, microemulsions are thermodynamically and physically stable systems while nanoemulsions are susceptible to Ostwald ripening, one of the main causes of physical instability. In this chapter, the two systems will be presented and compared. Their composition, preparation, and characterization methods will be discussed, and some examples of formulations and medicines that include micro-and nanoemulsions will be presented.
Springer Proceedings in Materials, 2019
Microemulsions are selected for topical delivery because of their stability and isotropic nature.... more Microemulsions are selected for topical delivery because of their stability and isotropic nature. Although microemulsion is macroscopically homogeneous, microscopically, it can be seen the presence of different structures such as oil droplets in water, water droplets in oil, bicontinuous, lamellar mixtures, etc., which can affect the rheology of these systems. The aim of this work was to study the influence of the amount of emollient and surfactant in the rheology of microemulsions for topical delivery.
Dermato, 2021
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Skin’s superficial fungal infections are diseases that affect most people worldwide. About 20 % t... more Skin’s superficial fungal infections are diseases that affect most people worldwide. About 20 % to 25 % of world's population is infected and the incidence continues to increase. There are a number of clinical presentations usually resulting from an infection by one of the dermatophyte species, notably Trichophyton rubrum. A number of modern treatment strategies are available and are generally well tolerated and effective. However, a significant proportion of patients, 2030 %, can expect treatment failure and/or relapse following treatment. The search for new treatment modalities and drugs is hampered by our lack of understanding of the basic pathophysiological mechanisms that underlie these frequently encountered infections. Ketoconazole (KTZ) is a synthetic, broad-spectrum antifungal drug. It is a potential inhibitor of ergoesterol (a main lipid membrane of fungi) synthesis. It is poorly soluble in water and unstable, specially in aqueous media. The purpose of this work was to...
Processes, 2021
There are several approaches to treat ocular diseases, which can be invasive or non-invasive. Wit... more There are several approaches to treat ocular diseases, which can be invasive or non-invasive. Within the non-invasive, new pharmaceutical strategies based on nanotechnology and mucoadhesive polymers are emerging methodologies, which aim to reach an efficient treatment of eye diseases. The aim of this work was the development of novel chitosan/hyaluronic acid nanoparticle systems with mucoadhesive properties, intended to encapsulate antioxidant molecules (e.g., crocin) aiming to reduce eye oxidative stress and, consequently, ocular disease. An ultraviolet (UV) absorber molecule, actinoquinol, was also added to the nanoparticles, to further decrease oxidative stress. The developed nanoparticles were characterized and the results showed a mean particle size lower than 400 nm, polydispersity index of 0.220 ± 0.034, positive zeta potential, and high yield. The nanoparticles were also characterized in terms of pH, osmolality, and viscosity. Mucoadhesion studies involving the determination...
Pharmaceutics, 2021
Semisolids constitute a significant proportion of topical pharmaceutical dosage forms available o... more Semisolids constitute a significant proportion of topical pharmaceutical dosage forms available on the market, with creams being considered profitable systems for releasing active substances into the skin. This work aimed at the development of a generic Clotrimazole topical cream, based on the assumptions that assist the development of such formulations. First, the critical parameters to obtain a final formulation as similar as possible to the reference product were defined. Then, the percentages of cetyl palmitate and octyldodecanol were identified as critical variables and chosen for optimization in further studies. A “quality by design” approach was then used to identify the effect of process variability on the structural and functional similarity (Q3) of the generic product qualitatively (Q1) and quantitatively (Q2). A two-factor central composite orthogonal design was applied and eleven different formulations were developed and subjected to physicochemical characterization and ...
Pharmaceutics, 2021
The by-products of olive oil industry are a major ecological issue due to their phenolic content,... more The by-products of olive oil industry are a major ecological issue due to their phenolic content, highly toxic organic load, and low pH. However, they can be recovered and reused, since their components have antioxidant, anti-inflammatory, and photoprotector properties. In this work, oil-in-water creams containing three different olive oil industry by-products extracts were produced without the use of organic solvents. First, the extracts were thoroughly characterized in vitro for cytotoxicity, inhibition of skin enzymes, and antioxidant and photoprotection capacities. Safety studies were then performed, including ocular and skin irritation tests, ecotoxicity evaluation, and in vivo Human Repeat Insult Patch Test. The results obtained in this initial characterization supported the incorporation of the extracts in the cream formulations. After preparation, the creams were characterized for their organoleptic, physicochemical, droplet size and rheological properties, and microbial con...
Cosmetics, 2020
Pickering emulsions are systems composed of two immiscible fluids stabilized by solid organic or ... more Pickering emulsions are systems composed of two immiscible fluids stabilized by solid organic or inorganic particles. Pickering emulsions are particularly useful in cosmetics, where the surfactants are unwanted, as well as in the pharmaceutical field, where transdermal and/or dermal drug delivery is difficult to achieve and controlled drug release is desired. Here, we studied calcium carbonate particles as stabilizers of Pickering emulsions for topical use. An optimized formulation was obtained using a Quality by Design approach. First, a screening experiment was performed to identify the formulation and process critical variables that affect the quality properties of the Pickering emulsion. The optimization of the production was then studied by establishing the design space. The final formulation was hereinafter investigated regarding the pH, rheological properties, and in vitro cytotoxicity assays. The results showed the formulation had a pH compatible with human skin and a shear ...
International Journal of Food Science & Technology, 2021
Pharmaceutics, 2020
The development of printable hydrogel inks for extrusion-based 3D printing is opening new possibi... more The development of printable hydrogel inks for extrusion-based 3D printing is opening new possibilities to the production of new and/or improved pharmaceutical forms, specifically for topical application. Alginate and starch are natural polysaccharides that have been extensively exploited due to their biocompatibility, biodegradability, viscosity properties, low toxicity, and relatively low cost. This research work aimed to study the physicochemical and release kinetic effects of starch incorporation in alginate-based 3D hydrogel patches for topical delivery using a quality by design approach. The incorporation of a pregelatinized starch is also proposed as a way to improve the properties of the drug delivery system while maintaining the desired quality characteristics. Critical material attributes and process parameters were identified, and the sensitivity and adequacy of each parameter were statistically analyzed. The impact of alginate, starch, and CaCl2·2H2O amounts on relevant ...
Applied Sciences, 2021
One of the new trends of personal care industry is the use of organic ingredients derived from na... more One of the new trends of personal care industry is the use of organic ingredients derived from nature, in particular, from food-processing residues with proven efficacy. Lycopene is a carotenoid responsible for the red color of several fruits, namely tomato, whose antioxidant and photoprotective effects have been studied. Methods: Lycopene-enriched extracts (LEE) were obtained from tomato waste using supercritical CO2 extraction, incorporated in microemulsions and macroemulsions for topical use, and characterized through GC-MS for the identification of volatile compounds. The aim of this work was to evaluate the impact of the presence of lycopene-enriched extracts developed emulsions through the identification of volatile compounds and by a sensory analysis to assess the odor and color perception and the acceptability of such semi-solid systems as cosmetic products. Results: Volatile compounds were identified in the extract and in the formulations containing the extract. Preliminary...
Journal of Sensory Studies, 2020
Molecules, 2020
With the increasing debate on sustainability, there is a strong market trend to formulate more su... more With the increasing debate on sustainability, there is a strong market trend to formulate more sustainable products for topical application. Several studies emphasize the potential applications of natural, organic, or green chemistry-derived ingredients, but comparative studies between conventional ingredients and sustainable alternatives are lacking. This type of study is considered an excellent baseline and time-saving strategy for future studies. In addition, one of the main challenges of replacing ingredients by sustainable alternatives in topical vehicles is to maintain high-quality products. Thus, the main goal of this research study was to create a well-defined strategy supported by specific experimental data for the development of sustainable topical vehicles with high-quality standards. The study was designed to evaluate the effects of replacing conventional ingredients (e.g., hydrocarbons, silicones, and preservatives) by sustainable ones on the physical, chemical, and mic...
Antioxidants, 2020
Skin aging is a biological process influenced by intrinsic and extrinsic factors. The last ones, ... more Skin aging is a biological process influenced by intrinsic and extrinsic factors. The last ones, mainly exposure to UV radiation, increases reactive oxygen species (ROS) production leading to a loss of extracellular matrix, also enhanced by enzymatic degradation of matrix supporting molecules. Thus, and with the growing demand for eco-friendly skin products, natural compounds extracted from brown seaweeds revealed to be good candidates due to their broad range of bioactivities, especially as antioxidants. The aim of this study was to assess the dermo-cosmetic potential of different fractions obtained from the brown seaweed Fucus spiralis. For this purpose, in vitro antioxidant (Total Phenolic Content (TPC), 1,1-Diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, Ferric Reducing Antioxidant Power (FRAP), Oxygen Radical Absorbance Capacity (ORAC)), anti-enzymatic (collagenase, elastase and hyaluronidase), antimicrobial, anti-inflammatory (NO production) and photoprotective (...
Pharmaceutics, 2020
Hypopigmentation is a progressive dermatological condition caused by a reduction in the skin pigm... more Hypopigmentation is a progressive dermatological condition caused by a reduction in the skin pigment, melanin. Its treatment is considered a challenge due to the lack of a highly efficient single therapy. Currently, the main treatments include photochemotherapy, application of corticosteroids and immunosuppressants, and laser. Khellin-based gel-in-oil emulsions appear as a promising alternative since they ensure a concentration of the drug, a natural furanochromone, at the desired location, skin surface. Khellin promotes repigmentation as it forms a dark colored complex after solar irradiation. The aim of this study was the development and characterization (e.g., rheological behaviour, droplet size, tackiness, adhesion and spreadability) of three topical gel-in-oil emulsions prepared with different emollients, formulated through a cold emulsification process, and suitable for the incorporation of khellin. In vitro studies were performed to evaluate the drug release and permeation pr...
Cells, 2020
Psoriasis is a common non-communicable chronic immune-mediated skin disease, affecting approximat... more Psoriasis is a common non-communicable chronic immune-mediated skin disease, affecting approximately 125 million people in the world. Its pathogenesis results from a combination of genetic and environmental factors. The pathogenesis of psoriasis seems to be driven by the interaction between innate immune cells, adaptive immune cells and keratinocytes, in a process mediated by cytokines (including interleukins (IL)-6, IL-17 and IL-22, interferon and tumor necrosis factor) and other signaling molecules. This leads to an inflammatory process with increased proliferation of epidermal cells, neo-angiogenesis and infiltration of dendritic cells in the skin. Dysfunctional de novo glucocorticoid synthesis in psoriatic keratinocytes and the skin microbiome have also been suggested as mediators in the pathogenesis of this disease. To understand psoriasis, it is essential to comprehend the processes underlying the skin immunity and neuroendocrinology. This review paper focuses on the skin as a...
Sustainability, 2020
Assessing sustainability is extremely necessary and appears as an industrial need and requirement... more Assessing sustainability is extremely necessary and appears as an industrial need and requirement in order to facilitate decision making and to evaluate the impacts of existing strategies, products and technologies. Thus, the main goal of this research was to develop a sustainability calculator based on the opinion of experts that work in the different branches of the cosmetic industry, in order to cover the entire life cycle of a cosmetic product. A detailed survey in which all the steps of a cosmetic product life cycle were addressed, was designed and applied to cosmetic professionals. The data obtained with the survey was statistically analysed for the positive and negative impacts of each parameter on sustainability. The analysed data allowed the creation of a Microsoft Excel tool that mirrors the experts’ opinion. A proof of concept was also designed in order to prove the usefulness of the tool. The results show that there are no raw materials and/or packaging materials and pra...
Pharmaceutics, 2019
Quercus Suber Bark from Quercus suber L. is a natural, renewable and biodegradable biomaterial wi... more Quercus Suber Bark from Quercus suber L. is a natural, renewable and biodegradable biomaterial with multifunctional proprieties. In this study, we used it as solid particles to stabilize a Pickering emulsion. The main goal was to produce an optimized topical formulation using biocompatible organic particles as stabilizers of the emulsion instead of the common surfactants, whilst benefiting from Quercus suber L. proprieties. In this work, a Quality by Design (QbD) approach was successfully applied to the production of this emulsion. A screening design was conducted, identifying the critical variables of the formula and process, affecting the critical quality attributes of the emulsion (droplet size distribution). The optimization of the production was made through the establishment of the design space. The stability was also investigated during 30 days, demonstrating that Quercus Suber Bark-stabilized emulsions are stable since the droplet size distribution lowers. In vitro studies w...
Journal of Microencapsulation, 2018
Abstract Pharmaceutical research has been focussed on developing improved delivery systems while ... more Abstract Pharmaceutical research has been focussed on developing improved delivery systems while exploring new ways of using approved excipients. The present work investigated the potential of starch nanocapsules (StNC) as a topical delivery platform for hydrophilic antimicrobial drugs using minocycline hydrochloride (MH) as a model drug. Thus, a quality by design approach was used to assess the role of different factors that affect the main pharmaceutical properties of StNC prepared using an emulsification–solvent evaporation method. Full characterisation was performed in terms of particle size, encapsulation efficiency, morphology and physical stability at 5 ± 3 °C. Results show the surfactant and lipid contents play a major role in StNC particle size distribution. The MH loading only promoted minor changes upon StNC properties. Formulations were stable without variations on physicochemical properties. All tested formulations presented a zeta-potential of +33.6 ± 6.7 mV, indicating a good physical stability and evidencing that StNC are suitable nanocarriers for topical use.
Pharmaceuticals, 2022
The use of natural products in dermatology is increasingly being pursued due to sustainability an... more The use of natural products in dermatology is increasingly being pursued due to sustainability and ecological issues, and as a possible way to improve the therapeutic outcome of chronic skin diseases, relieving the burden for both patients and healthcare systems. The legalization of cannabis by a growing number of countries has opened the way for researching the use of cannabinoids in therapeutic topical formulations. Cannabinoids are a diverse class of pharmacologically active compounds produced by Cannabis sativa (phytocannabinoids) and similar molecules (endocannabinoids, synthetic cannabinoids). Humans possess an endocannabinoid system involved in the regulation of several physiological processes, which includes naturally-produced endocannabinoids, and proteins involved in their transport, synthesis and degradation. The modulation of the endocannabinoid system is a promising therapeutic target for multiple diseases, including vascular, mental and neurodegenerative disorders. How...
Nanocarriers for Drug Delivery, 2021
Micro-and nanoemulsions are disperse systems widely used for the efficient and targeted drug deli... more Micro-and nanoemulsions are disperse systems widely used for the efficient and targeted drug delivery through various routes of administration. The difference between micro-and nanoemulsions is not related to the size scale, as the names suggest, since both systems might contain droplets with a diameter lower than 100 nm. The main difference between these two systems is that the droplet size of nanoemulsions is obtained by a mechanical reducing method, while microemulsions are formed spontaneously. Thus, microemulsions are thermodynamically and physically stable systems while nanoemulsions are susceptible to Ostwald ripening, one of the main causes of physical instability. In this chapter, the two systems will be presented and compared. Their composition, preparation, and characterization methods will be discussed, and some examples of formulations and medicines that include micro-and nanoemulsions will be presented.
Springer Proceedings in Materials, 2019
Microemulsions are selected for topical delivery because of their stability and isotropic nature.... more Microemulsions are selected for topical delivery because of their stability and isotropic nature. Although microemulsion is macroscopically homogeneous, microscopically, it can be seen the presence of different structures such as oil droplets in water, water droplets in oil, bicontinuous, lamellar mixtures, etc., which can affect the rheology of these systems. The aim of this work was to study the influence of the amount of emollient and surfactant in the rheology of microemulsions for topical delivery.
Dermato, 2021
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Skin’s superficial fungal infections are diseases that affect most people worldwide. About 20 % t... more Skin’s superficial fungal infections are diseases that affect most people worldwide. About 20 % to 25 % of world's population is infected and the incidence continues to increase. There are a number of clinical presentations usually resulting from an infection by one of the dermatophyte species, notably Trichophyton rubrum. A number of modern treatment strategies are available and are generally well tolerated and effective. However, a significant proportion of patients, 2030 %, can expect treatment failure and/or relapse following treatment. The search for new treatment modalities and drugs is hampered by our lack of understanding of the basic pathophysiological mechanisms that underlie these frequently encountered infections. Ketoconazole (KTZ) is a synthetic, broad-spectrum antifungal drug. It is a potential inhibitor of ergoesterol (a main lipid membrane of fungi) synthesis. It is poorly soluble in water and unstable, specially in aqueous media. The purpose of this work was to...
Processes, 2021
There are several approaches to treat ocular diseases, which can be invasive or non-invasive. Wit... more There are several approaches to treat ocular diseases, which can be invasive or non-invasive. Within the non-invasive, new pharmaceutical strategies based on nanotechnology and mucoadhesive polymers are emerging methodologies, which aim to reach an efficient treatment of eye diseases. The aim of this work was the development of novel chitosan/hyaluronic acid nanoparticle systems with mucoadhesive properties, intended to encapsulate antioxidant molecules (e.g., crocin) aiming to reduce eye oxidative stress and, consequently, ocular disease. An ultraviolet (UV) absorber molecule, actinoquinol, was also added to the nanoparticles, to further decrease oxidative stress. The developed nanoparticles were characterized and the results showed a mean particle size lower than 400 nm, polydispersity index of 0.220 ± 0.034, positive zeta potential, and high yield. The nanoparticles were also characterized in terms of pH, osmolality, and viscosity. Mucoadhesion studies involving the determination...
Pharmaceutics, 2021
Semisolids constitute a significant proportion of topical pharmaceutical dosage forms available o... more Semisolids constitute a significant proportion of topical pharmaceutical dosage forms available on the market, with creams being considered profitable systems for releasing active substances into the skin. This work aimed at the development of a generic Clotrimazole topical cream, based on the assumptions that assist the development of such formulations. First, the critical parameters to obtain a final formulation as similar as possible to the reference product were defined. Then, the percentages of cetyl palmitate and octyldodecanol were identified as critical variables and chosen for optimization in further studies. A “quality by design” approach was then used to identify the effect of process variability on the structural and functional similarity (Q3) of the generic product qualitatively (Q1) and quantitatively (Q2). A two-factor central composite orthogonal design was applied and eleven different formulations were developed and subjected to physicochemical characterization and ...
Pharmaceutics, 2021
The by-products of olive oil industry are a major ecological issue due to their phenolic content,... more The by-products of olive oil industry are a major ecological issue due to their phenolic content, highly toxic organic load, and low pH. However, they can be recovered and reused, since their components have antioxidant, anti-inflammatory, and photoprotector properties. In this work, oil-in-water creams containing three different olive oil industry by-products extracts were produced without the use of organic solvents. First, the extracts were thoroughly characterized in vitro for cytotoxicity, inhibition of skin enzymes, and antioxidant and photoprotection capacities. Safety studies were then performed, including ocular and skin irritation tests, ecotoxicity evaluation, and in vivo Human Repeat Insult Patch Test. The results obtained in this initial characterization supported the incorporation of the extracts in the cream formulations. After preparation, the creams were characterized for their organoleptic, physicochemical, droplet size and rheological properties, and microbial con...
Cosmetics, 2020
Pickering emulsions are systems composed of two immiscible fluids stabilized by solid organic or ... more Pickering emulsions are systems composed of two immiscible fluids stabilized by solid organic or inorganic particles. Pickering emulsions are particularly useful in cosmetics, where the surfactants are unwanted, as well as in the pharmaceutical field, where transdermal and/or dermal drug delivery is difficult to achieve and controlled drug release is desired. Here, we studied calcium carbonate particles as stabilizers of Pickering emulsions for topical use. An optimized formulation was obtained using a Quality by Design approach. First, a screening experiment was performed to identify the formulation and process critical variables that affect the quality properties of the Pickering emulsion. The optimization of the production was then studied by establishing the design space. The final formulation was hereinafter investigated regarding the pH, rheological properties, and in vitro cytotoxicity assays. The results showed the formulation had a pH compatible with human skin and a shear ...
International Journal of Food Science & Technology, 2021
Pharmaceutics, 2020
The development of printable hydrogel inks for extrusion-based 3D printing is opening new possibi... more The development of printable hydrogel inks for extrusion-based 3D printing is opening new possibilities to the production of new and/or improved pharmaceutical forms, specifically for topical application. Alginate and starch are natural polysaccharides that have been extensively exploited due to their biocompatibility, biodegradability, viscosity properties, low toxicity, and relatively low cost. This research work aimed to study the physicochemical and release kinetic effects of starch incorporation in alginate-based 3D hydrogel patches for topical delivery using a quality by design approach. The incorporation of a pregelatinized starch is also proposed as a way to improve the properties of the drug delivery system while maintaining the desired quality characteristics. Critical material attributes and process parameters were identified, and the sensitivity and adequacy of each parameter were statistically analyzed. The impact of alginate, starch, and CaCl2·2H2O amounts on relevant ...
Applied Sciences, 2021
One of the new trends of personal care industry is the use of organic ingredients derived from na... more One of the new trends of personal care industry is the use of organic ingredients derived from nature, in particular, from food-processing residues with proven efficacy. Lycopene is a carotenoid responsible for the red color of several fruits, namely tomato, whose antioxidant and photoprotective effects have been studied. Methods: Lycopene-enriched extracts (LEE) were obtained from tomato waste using supercritical CO2 extraction, incorporated in microemulsions and macroemulsions for topical use, and characterized through GC-MS for the identification of volatile compounds. The aim of this work was to evaluate the impact of the presence of lycopene-enriched extracts developed emulsions through the identification of volatile compounds and by a sensory analysis to assess the odor and color perception and the acceptability of such semi-solid systems as cosmetic products. Results: Volatile compounds were identified in the extract and in the formulations containing the extract. Preliminary...
Journal of Sensory Studies, 2020
Molecules, 2020
With the increasing debate on sustainability, there is a strong market trend to formulate more su... more With the increasing debate on sustainability, there is a strong market trend to formulate more sustainable products for topical application. Several studies emphasize the potential applications of natural, organic, or green chemistry-derived ingredients, but comparative studies between conventional ingredients and sustainable alternatives are lacking. This type of study is considered an excellent baseline and time-saving strategy for future studies. In addition, one of the main challenges of replacing ingredients by sustainable alternatives in topical vehicles is to maintain high-quality products. Thus, the main goal of this research study was to create a well-defined strategy supported by specific experimental data for the development of sustainable topical vehicles with high-quality standards. The study was designed to evaluate the effects of replacing conventional ingredients (e.g., hydrocarbons, silicones, and preservatives) by sustainable ones on the physical, chemical, and mic...
Antioxidants, 2020
Skin aging is a biological process influenced by intrinsic and extrinsic factors. The last ones, ... more Skin aging is a biological process influenced by intrinsic and extrinsic factors. The last ones, mainly exposure to UV radiation, increases reactive oxygen species (ROS) production leading to a loss of extracellular matrix, also enhanced by enzymatic degradation of matrix supporting molecules. Thus, and with the growing demand for eco-friendly skin products, natural compounds extracted from brown seaweeds revealed to be good candidates due to their broad range of bioactivities, especially as antioxidants. The aim of this study was to assess the dermo-cosmetic potential of different fractions obtained from the brown seaweed Fucus spiralis. For this purpose, in vitro antioxidant (Total Phenolic Content (TPC), 1,1-Diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, Ferric Reducing Antioxidant Power (FRAP), Oxygen Radical Absorbance Capacity (ORAC)), anti-enzymatic (collagenase, elastase and hyaluronidase), antimicrobial, anti-inflammatory (NO production) and photoprotective (...
Pharmaceutics, 2020
Hypopigmentation is a progressive dermatological condition caused by a reduction in the skin pigm... more Hypopigmentation is a progressive dermatological condition caused by a reduction in the skin pigment, melanin. Its treatment is considered a challenge due to the lack of a highly efficient single therapy. Currently, the main treatments include photochemotherapy, application of corticosteroids and immunosuppressants, and laser. Khellin-based gel-in-oil emulsions appear as a promising alternative since they ensure a concentration of the drug, a natural furanochromone, at the desired location, skin surface. Khellin promotes repigmentation as it forms a dark colored complex after solar irradiation. The aim of this study was the development and characterization (e.g., rheological behaviour, droplet size, tackiness, adhesion and spreadability) of three topical gel-in-oil emulsions prepared with different emollients, formulated through a cold emulsification process, and suitable for the incorporation of khellin. In vitro studies were performed to evaluate the drug release and permeation pr...
Cells, 2020
Psoriasis is a common non-communicable chronic immune-mediated skin disease, affecting approximat... more Psoriasis is a common non-communicable chronic immune-mediated skin disease, affecting approximately 125 million people in the world. Its pathogenesis results from a combination of genetic and environmental factors. The pathogenesis of psoriasis seems to be driven by the interaction between innate immune cells, adaptive immune cells and keratinocytes, in a process mediated by cytokines (including interleukins (IL)-6, IL-17 and IL-22, interferon and tumor necrosis factor) and other signaling molecules. This leads to an inflammatory process with increased proliferation of epidermal cells, neo-angiogenesis and infiltration of dendritic cells in the skin. Dysfunctional de novo glucocorticoid synthesis in psoriatic keratinocytes and the skin microbiome have also been suggested as mediators in the pathogenesis of this disease. To understand psoriasis, it is essential to comprehend the processes underlying the skin immunity and neuroendocrinology. This review paper focuses on the skin as a...
Sustainability, 2020
Assessing sustainability is extremely necessary and appears as an industrial need and requirement... more Assessing sustainability is extremely necessary and appears as an industrial need and requirement in order to facilitate decision making and to evaluate the impacts of existing strategies, products and technologies. Thus, the main goal of this research was to develop a sustainability calculator based on the opinion of experts that work in the different branches of the cosmetic industry, in order to cover the entire life cycle of a cosmetic product. A detailed survey in which all the steps of a cosmetic product life cycle were addressed, was designed and applied to cosmetic professionals. The data obtained with the survey was statistically analysed for the positive and negative impacts of each parameter on sustainability. The analysed data allowed the creation of a Microsoft Excel tool that mirrors the experts’ opinion. A proof of concept was also designed in order to prove the usefulness of the tool. The results show that there are no raw materials and/or packaging materials and pra...
Pharmaceutics, 2019
Quercus Suber Bark from Quercus suber L. is a natural, renewable and biodegradable biomaterial wi... more Quercus Suber Bark from Quercus suber L. is a natural, renewable and biodegradable biomaterial with multifunctional proprieties. In this study, we used it as solid particles to stabilize a Pickering emulsion. The main goal was to produce an optimized topical formulation using biocompatible organic particles as stabilizers of the emulsion instead of the common surfactants, whilst benefiting from Quercus suber L. proprieties. In this work, a Quality by Design (QbD) approach was successfully applied to the production of this emulsion. A screening design was conducted, identifying the critical variables of the formula and process, affecting the critical quality attributes of the emulsion (droplet size distribution). The optimization of the production was made through the establishment of the design space. The stability was also investigated during 30 days, demonstrating that Quercus Suber Bark-stabilized emulsions are stable since the droplet size distribution lowers. In vitro studies w...
Journal of Microencapsulation, 2018
Abstract Pharmaceutical research has been focussed on developing improved delivery systems while ... more Abstract Pharmaceutical research has been focussed on developing improved delivery systems while exploring new ways of using approved excipients. The present work investigated the potential of starch nanocapsules (StNC) as a topical delivery platform for hydrophilic antimicrobial drugs using minocycline hydrochloride (MH) as a model drug. Thus, a quality by design approach was used to assess the role of different factors that affect the main pharmaceutical properties of StNC prepared using an emulsification–solvent evaporation method. Full characterisation was performed in terms of particle size, encapsulation efficiency, morphology and physical stability at 5 ± 3 °C. Results show the surfactant and lipid contents play a major role in StNC particle size distribution. The MH loading only promoted minor changes upon StNC properties. Formulations were stable without variations on physicochemical properties. All tested formulations presented a zeta-potential of +33.6 ± 6.7 mV, indicating a good physical stability and evidencing that StNC are suitable nanocarriers for topical use.