OCTYLDODECANOL

Ethanolic extracts of Achyrocline satureioides have pronounced antioxidant activity mainly due to the presence of the flavonoid quercetin. However, direct topical application of the extract is not possible due to the presence of high amounts of ethanol. In this sense, nanoemulsions arise as an alternative for topical formulation associating molecules with limited aqueous solubility. This article describes the development of topical nanoemulsions containing either A. satureioides extract or one of its most abundant flavonoid, quercetin. Nanoemulsions composed of octyldodecanol, egg lecithin, water and extract (NEE), or quercetin (NEQ) were prepared by spontaneous emulsification. This process led to monodisperse nanoemulsions presenting a mean droplet size of approximately 200-300 nm, negative zeta potential, and high association efficiency. A study of quercetin skin retention using porcine skin which was performed using a Franz diffusion cell revealed a higher accumulation of quercetin in skin for NEE when compared to NEQ. Finally, the antioxidant activity of formulations was measured by thiobarbituric acid-reactive species and the APPH model. A lower lipoperoxidation for the extract in respect to quercetin solution was observed. However, no difference between NEQ and NEE lipoperoxidation could be seen. The protection against lipoperoxidation by the formulations was also measured in the skin, where lower formation of reactive species was observed after treatment with NEE. In conclusion, this study shows the formulation effect on the physicochemical properties of nanoemulsions as well as on the skin retention and antioxidant activity of quercetin.

This article describes the development of topical hydrogels containing genistein-loaded nanoemulsions, obtained by means of spontaneous emulsification. This procedure yielded monodisperse nanoemulsions in a sub 250 nm range exhibiting negative zeta-potential and low viscosity. The formulations were incorporated into acrylic-acid hydrogels in order to have their viscosity adjusted for topical application. The semisolid formulations exhibit non-Newtonian pseudoplastic behavior. The skin permeation/retention of genistein from formulations was carried out using porcine ear skin mounted in Franz diffusion cells under sink conditions. The results showed a slow flow of genistein through the skin. Higher amount of genistein was detected into the skin from the formulation composed by medium chain triglycerides as oily core when compared to the octyldodecanol one. The overall results show that hydrogels containing genistein-loaded nanoemulsions could be considered as a promising formulation to delivery isoflavones into the skin.

External environmental stressors and internal physiological changes frequently compromise the skin barrier, resulting in conditions such as dermatitis and dehydration. A key underlying factor is the depletion of ceramides, essential lipids in the stratum corneum that maintain skin integrity. Although topical ceramide supplementation is effective for barrier repair, its clinical application is limited by poor solubility and low skin permeability. To overcome these challenges, this study developed an oil-in-water nanoemulsion (O/W-NE) using ultrasonic emulsification for the efficient transdermal delivery of ceramide C2. Octyldodecanol was selected as the oil phase to enhance ceramide solubility, while glycerin was incorporated to increase aqueous phase viscosity, reduce particle size, and function as a biocompatible penetration enhancer. The optimized nanoemulsion achieved a particle size of 112.5 nm and an encapsulation efficiency of 85%. Its performance was evaluated via in vitro release, ex vivo skin permeation, and in vivo biocompatibility studies. Mechanistic investigations revealed that both particle size and glycerin concentration significantly influenced ceramide penetration into the epidermis and dermis. Additionally, the nanoemulsion exhibited moisturizing and barrier-repair effects in a damaged skin model. Overall, this O/W-NE offers a stable, non-invasive strategy for enhancing ceramide delivery and restoring skin barrier function.

Green and sustainable trends are growing and with that the demand for naturally derived ingredients is rising. Dispersing agents are essential components of lipsticks due to their ability to wet pigment particles, reduce agglomerates and prevent re-agglomeration by stabilizing pigment particles. In this study, meadowfoam seed oil was evaluated as a pigment-dispersing agent for lipsticks and compared with castor oil and octyldodecanol. Dispersions of Red 7 Lake were formulated with 20, 30 and 40% solid content using castor oil, octyldodecanol or meadowfoam seed oil. Particle size, viscosity, spreadability, wetting, oil absorption and colour were measured. Four of the nine dispersions were then formulated into lipsticks, including all the 30% pigment dispersions and the 40% dispersion with meadowfoam seed oil. Lipsticks were tested for hardness, pay-off, friction, rheology, colour and stability for 4 weeks. Average particle size was between 6 and 9 µm across the dispersions. The castor oil dispersions were more viscous, stickier and harder to spread than the other dispersions. The wetting contact angle was very low for all three dispersing agents, indicating that all of the oils wet the pigment well. The lipsticks varied in hardness, as expected, based on differences in the viscosity of the dispersing agents, and oil absorption of the powder. Red 7 Lake absorbed the highest amount of castor oil, which contributed to higher stick hardness. The castor oil lipstick and the meadowfoam seed oil lipstick containing 40% pigment were the hardest and most elastic. The octyldodecanol lipstick was the softest. Friction was the lowest for the meadowfoam seed oil lipstick containing 40% pigment, while pay-off was the highest for the octyldodecanol lipstick. The colour of the lipsticks as a stick and after being spread on paper was very similar. While the chemical composition and physicochemical properties of the dispersing agents were different, all three dispersing agents studied formed dispersions and lipsticks with appropriate characteristics. Meadowfoam seed oil's performance was qualitatively and quantitatively similar to castor oil and octyldodecanol. By modifying the amount of pigment and dispersing agent used, lipsticks that have similar characteristics to commercial products can be formulated. Les tendances écologiques et durables sont en hausse, ainsi que la demande en ingrédients d’origine naturelle. Les agents de dispersion sont des composants essentiels des rouges à lèvres en raison de leur capacité à mouiller les particules pigmentaires, à réduire les agglomérats et à prévenir la réagglomération en stabilisant les particules pigmentaires. Dans cette étude, l’huile de graines de limnanthe a été évaluée en tant qu’agent de dispersion pigmentaire pour les rouges à lèvres et comparée à l’huile de ricin et à l’octyldodécanol. MÉTHODES: Les dispersions de Red 7 Lake ont été formulées avec une teneur solide de 20, 30 et 40 % à l’aide d’huile de ricin, d’octyldodécanol ou d’huile de graines de limnanthe. La taille des particules, la viscosité, la facilité d’étalement, le mouillage, l’absorption de l’huile et la couleur ont été mesurés. Quatre des neuf dispersions ont ensuite été formulées dans des rouges à lèvres, y compris toutes les dispersions pigmentaires à 30 % et la dispersion à 40 % avec l’huile de graines de limnanthe. Les rouges à lèvres ont été testés pour la dureté, le résultat, la friction, la rhéologie, la couleur et la stabilité pendant 4 semaines. RÉSULTATS: La taille moyenne des particules était comprise entre 6&#xa0

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 product performance studies. The results were used to estimate the influence of the two variables in the variation of the responses, and to determine the optimum point of the tested factors, using a design space approach. Finally, an optimized formulation was obtained and analysed in parallel with the reference. The obtained results agreed with the prediction of the chemometric analysis, validating the reliability of the developed multivariate models. The in vitro release and permeation results were similar for the reference and the generic formulations, supporting the importance of interplaying microstructure properties with product performance and stability. Lastly, based on quality targets and response constraints, optimal working conditions were successfully achieved.

Transdermal delivery of therapeutic amounts of vitamin D3 is proposed to overcome its variable oral bioavailability, especially for people who suffer from fat malabsorption. The main challenge for this delivery route is to overcome the barrier properties of skin, especially for very lipophilic compounds such as vitamin D3. In this study, the effect of different penetration enhancers, such as oleic acid, dodecylamine, ethanol, oleic acid in propylene glycol, isopropyl myristate, octyldodecanol, and oleyl alcohol in propylene glycol were evaluated in vitro for their effectiveness in delivering vitamin D3 through polyamide filter, polydimethylsiloxane membrane, and porcine skin. A diffusion cell was used to study the transdermal permeability of vitamin D3. Ointment formulations of vitamin D3 were prepared containing the most widely used penetration enhancers, oleic acid, and dodecylamine. The ointment containing oleic acid as chemical penetration enhancer did not improve delivery compared to control. On the other hand, the formulation containing dodecylamine as a penetration enhancer did improve the transdermal delivery of vitamin D3. However, statistical significance and an amount high enough for nutritional supplementation purposes were reached only when the skin was pretreated with 50% ethanol. In these conditions, the ointment delivered an amount of 760-ng vitamin D3 per cm(2) of skin. The research shows promise that transdermal delivery could be an effective administration route for vitamin D3 when ethanol and dodecylamine are used as penetration enhancers.

This study describes the physico-chemical properties and the skin permeation profile of quercetin (Q) and 3-O-methylquercetin (MQ) from lipid nanoemulsions. Formulations composed of octyldodecanol, egg lecithin, water (NE) and cetyl trimethyl ammonium bromide (CNE) were obtained by spontaneous emulsification. This procedure yielded monodisperse nanoemulsions exhibiting a mean droplet size of approximately 200-300 nm. Nanoemulsions were further characterized in terms of zeta-potential, surface tension, and morphology by transmission electron microscopy. The amount of flavonoids incorporated into nanoemulsions reached nearly 100% (at 1 mg/mL). The permeation studies were carried out using ear pig skin mounted in Franz diffusion cells. The overall results have shown a slow permeation profile of both Q and MQ from nanoemulsions. However, a higher permeation flux rate of flavonoids from CNE (approximately 0.2 microg/cm2/h) as compared to NE (approximately 0.08 microg/cm2/h) was observed, showing the effect of the positively charged surface of CNE on this parameter. Such results open interesting perspectives for the topical administration of the flavonoids Q and MQ.

We have recently described the incorporation of genistein into topical nanoemulsions. This study describes the physicochemical properties and the genistein permeation profile from these nanoemulsions. Formulations composed of egg lecithin, medium chain triglycerides (MCT) or octyldodecanol (ODD) and water were prepared by spontaneous emulsification. Irrespective of the oil core employed (MCT or ODD), this procedure yielded monodisperse emulsions with mean droplet sizes in the range of 230-280 nm. The addition of genistein in the oil phase, before emulsification, did not alter the properties of nanoemulsions. The amount of genistein incorporated in both formulations was close to 100% (1 mg/mL). Solubility and DSC experiments suggested that egg-lecithin may play an important role on the incorporation of genistein in nanoemulsions. Genistein permeation from formulations was assessed using pig ear skin in Franz type diffusion cells. The overall results showed a slow permeation profile for genistein from both nanoemulsions.Such results open interesting perspectives for the topical administration of genistein.

The aim of this study was to develop and validate an isocratic LC method for the quantification of genistein in topical nanoemulsions. The analyses were performed at room temperature on a reversed-phase C18 column using a mobile phase composed of methanol/water/acetonitrile (70:25:5, w/w/w) at 1.0 ml x min(-1). The detection was carried out on a UV detector at 327 nm. The linearity, in the range of 25-75 microg/ml, presented a determination coefficient (r2) higher than 0.999, calculated by the least square method. No interferences from the excipients (egg-lecithin, octyldodecanol or medium chain triglycerides) were detected. The R.S.D. values for intra- and inter-day precision experiments were lower than 2.3%. The recovery of genistein from nanoemulsions ranged from 96.6% to 106.6%. The excellent performance of the method, its linearity, accuracy and precision, demonstrate that it can be readily used to quantify genistein incorporated in nanoemulsions.

The lipophilic character of five vehicles (or co-vehicles): diethylhexylmaleate, dimethicone, light mineral oil, octyldodecanol and oleyl alcohol and eight botanical oils: Aloe vera oil, coconut oil, extra virgin olive oil, grape leaf oil, grape seed oil, hazelnut oil, jojoba oil and safflower oil was determined by partitioning esters of p-hydroxybenzoic acid (parabens) between them and phosphate buffer (pH 7.4). The results were compared to those obtained with 1-octanol. The most lipophilic effects were observed with octyldodecanol and oleyl alcohol for the vehicles (or co-vehicles), coconut oil, jojoba oil and safflower oil for botanical oils. Light mineral oil showed the least lipophilic effect. With butylparaben, it was observed that oleyl alcohol, octyldodecanol, coconut oil and jojoba oil were 0.94, 0.91, 0.74 and 0.68 times as lipophilic as 1-octanol respectively. The study indicates that octyldodecanol and oleyl alcohol could be good substitutes for 1-octanol in partition coefficient determination. The estimated permeability coefficients of the parabens suggest that octyldodecanol, oleyl alcohol, coconut oil and jojoba oil could be potential dermal permeation enhancers.

The aim of this study was to validate an isocratic LC method for the quantification of either quercetin (Q) or methylquercetin (MQ) incorporated in topical nanoemulsions. The analyses were performed at room temperature on a reversed-phase C(18) column using a mobile phase composed of methanol/water (70:30, v/v) and trifluoracetic acid 0.1% at 0.8 mL min(-1). The detection was carried out on a UV detector at 368 or 354 nm for Q and MQ, respectively. The linearity, in the range of 0.15-1.5 microg/mL, presented a determination coefficient (r(2)) higher than 0.99, calculated by the least square method for both flavonoids. No interferences from the excipients (egg-lecithin or octyldodecanol) were detected. The R.S.D. values for intra- and inter-day precision experiments were lower than 2% for both flavonoids. The recovery ranged from 98.9% to 103.46% for Q and from 98.9% to 102.92% for MQ.