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Monographs of fragrance chemicals and extracts that have caused contact allergy / allergic contact dermatitis
Published in Anton C. de Groot, Monographs in Contact Allergy, 2021
Cyclohexyl acetate is a colorless to pale yellow clear liquid; its odor type is fruity and its odor is described as ‘solventlike and fruity sweet with banana and apple nuances’ (www.thegoodscentscompany.com). Cyclohexyl acetate is a synthetic chemical used as a fragrance and flavor. It is also a good solvent for cellulose ethers and nitrocellulose and has powerful solvency for basic dyes, blown oils, raw rubber, metallic soaps, driers, shellac, bitumen, and a wide range of natural and synthetic resins and gums. The chemical is used in spraying and brushing lacquers imparting blush resistance and good flow (U.S. National Library of Medicine).
Dermal and Transdermal Drug Delivery Systems
Published in Tapash K. Ghosh, Dermal Drug Delivery, 2020
Kenneth A. Walters, Majella E. Lane
Topical treatment of skin and nail diseases is desirable in terms of patient acceptability and reduction of side effects associated with systemic drug delivery. This is particularly the case for nail diseases as they are frequently difficult to cure and require long periods of treatment compared with the skin. The nail plate is a highly keratinized tissue, which is characterized by low permeability to diffusing compounds, hence its barrier properties represent a significant challenge for formulation scientists. Currently, actives to treat nail fungal infections are available in lacquer form where the volatile formulation components evaporate to leave a residual film on the nail surface. Despite many literature reports employing chemical and physical enhancement strategies to enhance drug delivery to the nail, new formulation strategies have not impacted on this field to date (Walters et al., 2012).
The Human Nail: Structure, Properties, Therapy and Grooming
Published in Heather A.E. Benson, Michael S. Roberts, Vânia Rodrigues Leite-Silva, Kenneth A. Walters, Cosmetic Formulation, 2019
Kenneth A. Walters, Majella E. Lane
Hui et al. (2007a) investigated a range of different nail lacquers and a co-solvent vehicle for delivery of a novel oxaborole antifungal to the nail. Lacquers were formulated with a film-forming agent, solvent, and, optionally, a penetration enhancer. Ethanol was the solvent, poly (vinyl methyl ether alt maleic acid monobutyl ester), poly (2-hydroxyethyl methacrylate), poly (vinyl acetate) were the film formers. The co-solvent vehicle consisted of ethanol and propylene glycol. Approximately the same amount of the test compound penetrated the nail plates regardless of the vehicle. The co-solvent vehicle showed a superior permeation capability into and through the normal human nail plate in vitro compared with a commercial formulation of ciclopirox (Penlac®, ciclopirox 8%).
Hydroxypropyl chitosan nail lacquer of ciclopirox-PLGA nanocapsules for augmented in vitro nail plate absorption and onychomycosis treatment
Published in Drug Delivery, 2022
Eman Yahya Gaballah, Thanaa Mohammed Borg, Elham Abdelmonem Mohamed
The optimized NCs (F3) and its HPCH nail lacquer (L3) showed average low pH of 3.46 ± 0.01 and 3.97 ± 0.15, respectively, possibly due to the ionization of acidic groups of PLGA polymer chain (de Melo et al., 2011). The basic nature of HPCH may account for the significantly (p < 0.05) higher average pH values of the lacquer when compared to that of the optimized NCs dispersion (Bansal et al, 2011). The average relative viscosity of the optimized NCs was 1.2 ± 0.01 CP. The significantly (p < 0.05) higher viscosity of its nail lacquer (4.23 ± 0.06 CP) relative to that of NCs dispersion is expected to prolong the contact time on the nail plate that could permit a proper hydration and a drug absorption across the nails as well as an improved storage stability due to the hindered aggregation. The higher viscosity of the lacquer when compared to that of dispersion can be explained by the effects of HPCH as a thickening agent.
Feasible and eco-friendly removal of hexavalent chromium toxicant from aqueous solutions using chemically modified sugarcane bagasse cellulose
Published in Toxin Reviews, 2021
Ahmed Eleryan, Ahmed El Nemr, Abubakr M. Idris, Majed M. Alghamdi, Adel A. El-Zahhar, Tarek O. Said, Taher Sahlabji
Cellulose was extracted from sugarcane bagasse. Two hundred grams of dried sugarcane bagasse was placed in a 5-L round bottom flask. Four liters of 2% NaOH was added and the mixture was heated at 70 °C for 2 h in a water bath (Gurgel and Gill 2009b, Shin et al. 2012). The residual pulp was washed several times with double-distilled deionized water to eliminate the black lacquer before filtration. The residual pulp was bleached twice by 4 L of 50% NaClO and 100 ml of acetic acid at 70 °C for 2 h and washed again with double-distilled deionized water. Extra bleaching was performed with 4 L of 0.5% H2O2 at 70 °C for 2 h followed by washing with double-distilled deionized water. Finally, the produced white pulp was dried in an oven at 50 °C and pulverized for chemical modification.
Update on current approaches to diagnosis and treatment of onychomycosis
Published in Expert Review of Anti-infective Therapy, 2018
Aditya K. Gupta, Rachel R. Mays, Sarah G. Versteeg, Neil H. Shear, Vincent Piguet
The two newly approved topical antifungals, efinaconazole and tavaborole, are both formulated as solutions as opposed to lacquers [50,51]. In order for the solution to be effective the antifungal needs to reach the nail bed and matrix, and accumulate in the nail plate. The nail plate has poor permeability and access to circulation so the solution-based formula allows the application of drug to the stratum corneum and subungual space (subungual delivery) in addition to the ventral aspect of the nail plate (transungual delivery) [64]. As opposed to lacquer, solutions do not require patients to remove the application weekly, which is an inconvenience that may affect patient compliance.