China
Africa
Explore chapters and articles related to this topic
Polysaccharide-Based Polymers in Cosmetics
Published in E. Desmond Goddard, James V. Gruber, Principles of Polymer Science and Technology in Cosmetics and Personal Care, 1999
E. Desmond Goddard, James V. Gruber
Hydroxypropylmethylcellulose shares characteristic solution properties of both HPC and MC. It has been suggested that HPMC, like MC, enhances surfactant foaming through interfacial gelation (164). Because of its inherent lipophilicity and surface activity HPMC maintains stable oil-in-water emulsions even after heat sterilization (165,166). This provides unique opportunities to prepare sterile creams and lotions for pharmaceutical and dermatological applications. Ethylhydroxyethylcellulose. EHEC (39) is included here even though it has limited applications in personal care. The interest in EHEC stems from its ability to gel at temperatures only slightly above 30∘C, particularly in the presence of anionic and cationic surfactants (167-169). The hydrophobic domains on EHEC build strong interpolysaccharide cross-links as the polysaccharide solution is warmed. This thermal gelation effect is sensitive to the concentrations of the EHEC and surfactant employed (169). The lipophilic nature of the ether substituents on EHEC all but qualify it as a hydrophobically modified HEC (Section III.E.).
Validation of Oral/Topical Liquids and Semi-Solids
Published in James Agalloco, Phil DeSantis, Anthony Grilli, Anthony Pavell, Handbook of Validation in Pharmaceutical Processes, 2021
Creams are emulsions consisting of oils dispersed in aqueous medium. The active can be in either the oil or the water phase. Alternatively, a non-active cream base may contain a suspended solid. In either case, the physical characteristics of the cream can govern the quality of the final preparation. The cream base CPPs and CQAs are generally restricted to the physical parameters of viscosity, specific gravity or density, and homogeneity. Final formulated bulk adds API assay(s), bioburden, preservative assay, and efficacy to the cream base CPPs and CQAs.
Optimization of clobetasol propionate loaded niosomal gel for the treatment of psoriasis: Ex vivo and efficacy study
Published in Journal of Dispersion Science and Technology, 2022
The assembly was dismantled after 24 h of the ex vivo study, and the amount of clobetasol propionate retained over the skin tissue, deposited in the stratum corneum and the VED layers was quantified by Liquid chromatography–mass spectrometry (LCMS) (Figure 3). In marketed cream USP group, the amount of clobetasol propionate deposited in the stratum corneum and the VED layers was 1.26 ± 0.12% and 3.56 ± 2.3% respectively. While, the amount of drug retained on the skin tissue was very high (86.62 ± 5.6%) due to poor permeation profile of pure clobetasol propionate. In case of niosomal gel, high clobetasol propionate deposition was noted (stratum corneum = 6.26 ± 1.4% and VED = 18.45 ± 2.3%) which clearly suggest the effectiveness of niosomes to improve drug deposition in the skin tissues due to efficient fusion of nanoparticles in the skin tissue. The lipid rich epidermis (target site) could act as drug depot for lipophilic carriers where psoriasis originates. Thus, application of niosomes could be effective to treat psoriasis. Langasco et al. noted 12% deposition of clobetasol propionate using bio-based microemulsion prepared using lecithin and isopropyl myristate.[41]
Preparation and evaluation of polymer-encapsulated UV filter nanocapsules with miniemulsion polymerization
Published in Journal of Dispersion Science and Technology, 2021
Qing An, Xinjiong Ni, Dong Liu, Yun Zhang, Yuhua Cao
As shown in Figure 7, without UV filter, the SPF value of base cream was 4.30. As 1.7% free OD-PABA added in base cream, the SPF value of the sunscreen was 6.20. Unexpectedly, as 8.3% PMMA nanoparticles without organic UV filter in base cream, the SPF value of the sunscreen was 8.30, even larger than that of free OD-PABA sunscreen. The solid UV reflection spectrum of PMMA nanoparticles testified that it has UV broad-spectrum reflection and strong UV radiation blocking. Such good performance of PMMA nanoparticles as the physical UV filter resulted from the strong reflection and scattering. Once 10% UV filter nanocapsules (containing 1.7% OD-PABA and 8.3% PMMA coating material) was added in base cream, the SPF of the sunscreen had 22.80, improved by 300% compared with free OD-PABA sunscreen. Admittedly, the nanocapsules encapsulated OD-PABA could prominently improve UV blocking performance.
Treatment of wastewater containing oil and grease by biological method- a review
Published in Journal of Environmental Science and Health, Part A, 2021
P. Sanghamitra, Debabrata Mazumder, Somnath Mukherjee
The oil droplets with more or less same rising velocities, move in upward direction in case of oil-in-water emulsion with monodispersed system (same size droplets), hence forming a droplet rich cream layer at the upper part and a droplet-depleted serum layer at base of the container. The intermediate emulsion layer separating cream and serum layer is close to the original emulsion. A decrease in depth of emulsion layer and increase in cream and serum layer with respect to time was observed as shown in Figure 1. The re-dispersion of droplets in creamed layer with gentle agitation indicates weak attraction between the droplets. There is creaming of droplets at diverse velocities in case of oil-in-water emulsion of polydisperse type (containing various sizes of droplets) as smaller droplets cream moves less quickly than larger ones as shown in Figure 2. The spatial location of numerous droplets with a function of time governs the stability for oil-in-water emulsions.[47]