STEARYL ALCOHOL

To establish an in vitro release (IVR) method for butenafine hydrochloride cream using Immersion Cells and compare the drug release characteristics of commercial samples. Reevaluating post-listing semisolid drug products based on quality attributes of IVR performance is crucial for guaranteeing clinical efficacy. An in vitro release testing (IVRT) method using Immersion Cells was developed and validated for sensitivity, linearity, and reproducibility. It was adapted for use with Vertical Diffusion Cells (VDCs) to compare two devices. Univariate tests were conducted to assess the effect of excipients on in vitro release rates (IVRRs). Three regulatory guidelines recommended by FDA, NMPA and EMA for IVR performance consistency assessment were compared to evaluate the sameness of marketed samples. For IVRT of butenafine hydrochloride cream, Immersion Cells exhibited the same functionality as VDCs. Stearyl alcohol which serves as oil phase matrix and thickener in the cream had a significant impact on IVRRs. Regarding the consistency of marketed samples, FDA guidelines supported a consistent conclusion, while NMPA and EMA guidelines reached the opposite conclusion, which were primarily attributed to different acceptance criteria outlined in the three regulatory guidelines. Additional strategies are needed to ensure consistent therapeutic outcomes of butenafine hydrochloride cream throughout its life cycles, such as stricter control of stearyl alcohol dosage during manufacturing. Further research is needed to explore appropriate limits for consistency assessment of it. Immersion Cells offers the advantage of lower cost in routine quality control and its application in IVRT for semisolid formulations merits further expansion.

Traditionally, cosmetic emulsions have been developed using trial-and-error approaches, which can be ineffective and time-consuming. This study employed a Quality by Design approach to determine how formulation ingredients impact the physical stability of a sustainable sunscreen. A 2 3 full factorial design assessed the effects of the concentrations of polyglyceryl-2 stearate, glyceryl stearate, stearyl alcohol (self-emulsifier), brassica glycerides (co-emulsifier), and xanthan gum (gelling agent) on the apparent viscosity and instability index of the emulsified vehicle. Another 2 3 full factorial design evaluated the effects of the concentration of zinc oxide, titanium dioxide, and phytic acid on the instability index of the sustainable sunscreen formulation. The instability index of the emulsified vehicle was influenced by self-emulsifier and co-emulsifier concentrations. In contrast, its apparent viscosity was influenced by self-emulsifier and gelling agent concentrations, and by interactions among self-emulsifier, co-emulsifier, and gelling agent. The instability index of the sunscreen formulation was mainly influenced by zinc oxide and phytic acid concentrations. Robust mathematical models were developed and used to predict the optimal compositions of the emulsified vehicle and sunscreen formulation within the experimental domains. The optimal compositions predicted by the mathematical models developed were 8% self-emulsifier, 3% co-emulsifier, and 0.3% gelling agent for the emulsified vehicle, and 6.3% zinc oxide, 2% titanium dioxide, and 1% phytic acid for the sunscreen formulation. These optimized formulations met the Quality Target Product Profiles, ensuring appropriate physical stability, rheological performance, antioxidant properties, and the desired SPF, water resistance, and UVA-PF characteristics.

Psoriasis is a chronic inflammatory skin disease. Topical medicines are the preferred treatment for mild to moderate psoriasis, but the effect of excipients used in semi-solid preparations on psoriasis-like skin inflammation is not fully understood. In the present study, we investigated the effect of stearyl alcohol, a commonly used excipient, on imiquimod (IMQ)-induced psoriasis-like skin inflammation in mice. Psoriasis-like skin inflammation was induced by topical IMQ treatment on the back of mice. Skin lesion severity was evaluated by using psoriasis area and severity index (PASI) scores. The skin sections were stained by haematoxylin-eosin and immunohistochemistry. Stearyl alcohol (20% in vaseline) treatment significantly reduced the IMQ-induced increase of PASI scores and epidermal thickness in mice. IMQ treatment increased the number of Ki67- and proliferating cell nuclear antigen (PCNA)-positive cells in the skin, and the increases were inhibited by stearyl alcohol (20% in vaseline) treatment. Stearyl alcohol treatment (1%, 5%, 10% in vaseline) dose-dependently ameliorated IMQ-induced increase of PASI scores and epidermal thickness in mice. Hexadecanol (20% in vaseline), stearic acid (20% in vaseline) and vaseline treatment had no significant effect on IMQ-induced psoriasis-like skin inflammation in mice. In conclusion, stearyl alcohol has the effect of improving IMQ-induced psoriasis-like skin inflammation in mice.

Imiquimod (IMQ) is an immunomodulating drug that is approved for the treatment of superficial basal cell carcinoma, actinic keratosis, external genital warts and perianal warts. However, IMQ cream (Aldara ® ) has several drawbacks including poor skin permeation, local toxicity, and compromised patient compliance as a topical pharmacological option. Our research aimed to develop and optimize nanostructured lipid carriers (NLCs) containing IMQ for the first time using a hybrid design of experiments approach. The optimized formulation was then incorporated into a matrix-type topical patch as an alternative dosage form for topical application and evaluated for IMQ deposition across different skin layers in comparison to the performance of the commercial product. Additionally, our work also attempted to highlight the possibility of implementing environment-friendly practices in our IMQ-NLCs formulation development by reviewing our analytical methods and experimental designs and reducing energy and solvent consumption where possible. In this study, stearyl alcohol, oleic acid, Tween ® 80 (polysorbate 80), and Gelucire ® 50/13 (Stearoyl polyoxyl-32 glycerides) were selected for formulation development. The formulation was optimized using a 2 k factorial design and a central composite design. The optimized formulation achieved the average particle size, polydispersity index, and zeta potential of 75.6 nm, 0.235, and - 30.9 mV, respectively. Subsequently, a matrix-type patch containing IMQ-NLCs was developed and achieved a statistically significant improvement in IMQ deposition in the deeper skin layers. The IMQ deposition from the patch into the dermis layer and receptor chamber was 3.3 ± 0.9 µg/cm 2 and 12.3 ± 2.2 µg/cm 2 , while the commercial cream only deposited 1.0 ± 0.8 µg/cm 2 and 1.5 ± 0.5 µg/cm 2 of IMQ, respectively. In summary, IMQ-NLC-loaded patches represent great potential as a topical treatment option for skin cancer with improved patient compliance.

Background: Patients with chronic wounds have an increased risk of developing allergic contact dermatitis (ACD). Reports of ACD to wound care products are not uncommon. To minimize contact sensitization in patients with chronic wounds, allergenic ingredients should be avoided when possible. Objective: With more than 5000 wound care products available in the United States, it is essential to understand which products can be chosen to minimize allergen exposures. Methods: Ingredients in wound care products in 5 wound care clinics across 2 institutions were cross-referenced with the American Contact Dermatitis Society core allergen series 2020. Results: Of the 267 wound care products included, 97 (36.3%) contained at least one allergen, including 31 dressings/wraps (22.3%), 25 medications (69.4%), 12 cleaning supplies (36.3%), 16 tapes/glues (80%), 2 instruments (14.3%), 8 emollients and vehicles (61.5%), 1 ostomy product (11.1%), and 2 odor-eliminating products (66.7%). Thirty-four different allergens were identified across all products. The most common allergens present in the included items were acrylates and propylene glycol, followed by parabens, cetyl stearyl alcohol, tocopherol, fragrance, and phenoxyethanol. Conclusions: Many wound care products contain at least one contact allergen, highlighting the importance of clinician education on ACD in the context of wound care product selection.

Stearyl alcohol is found in various cosmetics and topical medications and is regarded as safe. Allergic contact dermatitis is reported due to this chemical on rare occasions. We report seven cases, comprising three men and four women aged between 36 and 62 between the years 2013 to 2019, of allergic contact dermatitis due to the use of topical medication, where the patient showed a positive result to a patch test using stearyl alcohol. There were 10 topical medications that we considered to be the cause of this: three were from Oronine ® H ointment, two from Eurax ® cream, one from Eurax H cream, and four from topical antifungal medications. All these medications contained stearyl alcohol. Seven cases of patch tests with stearyl alcohol all showed positive results. Moreover, having done a patch test with cetyl alcohol, two out of three tests showed positive. When researching allergic contact dermatitis due to topical medications, it is important to test for allergy to stearyl alcohol as well as their main ingredients, because it is contained in numerous products and has the ability to cause allergic contact dermatitis.

This study aims to develop coenzyme Q10 nanostructured lipid carriers (NLCs) using tristearin and stearyl alcohol as well as isopropyl palmitate (IPP) as solid and liquid lipid respectively for the dermal delivery system. The coenzyme Q10 NLCs were optimized using tristearin, and stearyl alcohol in different concentrations and further characterized by dynamic light scattering (DLS) for particle size, polydispersity index (PDI), zeta potential, differential scanning calorimetry (DSC) and X-ray diffractometry for crystallinity behavior, Fourier transform infrared spectroscopy (FT-IR) for drug-lipid interaction, scanning electron microscopy (SEM) for particle shape, viscometer for viscosity, and pH meter for pH value. Furthermore, entrapment efficiency (EE), drug loading (DL), and skin penetration in vivo were also evaluated while molecular docking was conducted to examine the interaction between coenzyme Q10 and the lipids. The coenzyme Q10 NLCs with tristearin-IPP and stearyl alcohol-IPP as lipid matrix had <1,000 nm particle size, <0.3 PDI, less negative than -30 mV zeta potential, about 41% crystallinity index, and about six as the pH value. Moreover, the EE, DL, viscosity, and in vivo skin penetration of the NLCs using tristearin were higher compared to stearyl alcohol, however, the skin penetration depths for both NLCs were not significantly different. Furthermore, the in silico binding energy of coenzyme Q10-tristearin was lower compared to coenzyme Q10-stearyl alcohol. Both of them showed hydrophobic and van der Waals interaction. The NLCs of coenzyme Q10 were formulated successfully using tristearin-IPP and stearyl alcohol-IPP for dermal delivery.

An in vivo analysis of stearyl alcohol and stearic acid films on the skin surface using polarized infrared-external reflection spectroscopy revealed that whether the sample molecules adopt an energetically stable conformation and orientation strongly depends on the molecular functionalities and sample preparation conditions. For stearic acid, even the difference in solute concentration between 0.1 and 0.5 wt% results in a different molecular conformation and orientation. This illustrates that the molecular organization of the adsorbate on the skin surface is sensitively determined by the kinetics of the sample film growth, not by the simple thermodynamic equilibrium with the skin temperature.

Topical 5-fluorouracil has proven to be an effective treatment for flat warts. Although cases of local irritation at the site of application have been reported, allergic contact dermatitis on the adjacent normal skin is generally uncommon. Reactions to propylene glycol and stearyl alcohol, two vehicle components of 5-fluorouracil, have also been described. In this report, we present a 21-year-old woman who developed allergic contact dermatitis of the adjacent normal skin after topical application of 5-fluorouracil to the face for the treatment of flat warts.

In oleogel food systems (based on the mixture between stearic acid and stearyl alcohol) the strong effect of the weight ratio (R) between these two components on the textural and structural properties is well described. The effect of R for other fatty acids and fatty alcohols is less explored. Moreover, they do not show an enhancement of the oleogel properties for specific R. The effect of R on the oleogel properties, for a mixture of fatty acid and fatty alcohol with longer alkyl chains (behenyl alcohol and behenic acid) in sunflower and soybean oils, which are raw materials widely used in cosmetic and pharmaceutical industries, was investigated. We characterized the oleogel properties as a function of R in terms of structuring potential: hardness, oil loss and gel stability. This information was correlated with microstructural data obtained at different length scales by coupling optical microscopy, DSC, SFC, SAXS and WAXS experiments. Our results highlight that R tunes the oleogel properties in a comparable manner to previous results obtained for stearic acid and stearyl alcohol-based oleogels. Two specific R (8:2 and 7:3) close to the 3:1 molecular ratio gave oleogels with both the highest hardness and stability. The morphology and size of the mixed crystals obtained for these R cannot solely explain why they are stronger gels with low oil loss in comparison to the other R. The almost complete crystallization for these two R is one of the key parameters controlling the oleogel properties. As described in the literature, we also suggest that the differences in oleogel properties come from the spatial distribution of the crystalline mass. In this study, we confirm that the effect of the 3:1 molecular ratio in mixed surfactant systems described more than 50 years ago for foams, emulsions and Langmuir monolayers occurs also on the crystallization of mixed fatty alcohol and fatty acid in oils leading to better oleogels properties.

Premenstrual syndrome (PMS) is experienced by many women who suffer from either its psychological or physical symptoms. Current treatment is limited to symptomatic therapy or oral contraceptives. On the other hand, l-theanine, which has a relaxant effect, has been reported to be useful for PMS, but its short half-life when administered orally makes it less effective. Permeability and properties of transdermal gel containing l-theanine were evaluated as a preclinical study of PMS symptoms relief formulation. Lyogel composed of stearic acid, stearyl alcohol, and propylene glycol was selected. The ratio of these components and the preparation method were investigated. Permeation of Strat-M membranes was evaluated by using Franz cells ( in vitro ). Moreover, lyogel was applied to institute of cancer research mice's backs for 10 days to examine the permeability of l-theanine. l-Theanine solution did not permeate the Strat-M membrane at all in the permeation study, but lyogel allowed l-theanine to permeate. When the composition of lyogel was 4.4:11.1:296 (mmol) for stearic acid, stearyl alcohol, and propylene glycol, l-theanine absorption through Strat-M membrane was better. In skin permeation study using mice, l-theanine was detected in the serum, that is, it was proven that l-theanine penetrated the skin. The preparation of transdermal gels contained l-theanine was investigated as a preclinical study. The skin permeability of semisolid formulations of hydrophobic ointments, hydrophilic ointments, oily creams, creams, and lyogel containing theanine was compared and found that lyogel was the best. The composition of lyogel was also studied to obtain a formulation with good application comfort. Although it is suggested that this lyogel could be tested in clinical studies to determine whether it is effective for relief of PMS symptoms, lyogel may be suitable as an easy-to-use l-theanine-containing formulation for women that can relieve PMS symptoms.