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Chemical Modulation of Topical and Transdermal Permeation
Published in Marc B. Brown, Adrian C. Williams, The Art and Science of Dermal Formulation Development, 2019
Marc B. Brown, Adrian C. Williams
Surfactants are found in many existing therapeutic, cosmetic, and agrochemical preparations, and are clearly a major component of cleansing products (soaps, shampoos, etc.). Usually surfactants are added to formulations to solubilise lipophilic- active ingredients, and so they have potential to solubilise lipids within the stratum corneum. Generally composed of a lipophilic alkyl or aryl fatty chain, together with a hydrophilic head group, surfactants are often described in terms of their hydrophile-lipophile balance (HLB). The HLB provides a measure of whether the surfactant is hydrophilic or lipophilic, drawn from the nature of the polar head group and hydrophobic fatty chain. The HLB value has thus been proposed as a means to predict penetration enhancement activity, but the literature shows that this is not a reliable tool, since the size and shape of the head and tail groups influence their enhancement activity.
Solid Lipid Nanoparticles for Anti-Tumor Drug Delivery
Published in Mansoor M. Amiji, Nanotechnology for Cancer Therapy, 2006
Ho Lun Wong, Yongqiang Li, Reina Bendayan, Mike Andrew Rauth, Xiao Yu Wu
The main functions of surfactants in SLN are to disperse the melt lipid into aqueous phase in the SLN preparation process and then to stabilize the nanoparticles after cooling. A surfactant molecule has a hydrophilic head and lipophilic tail to reduce the surface tension between two phases. The hydrophile-lipophile balance (HLB) value of surfactants represents the relative proportion of the hydrophilic and lipophilic parts of the molecule.
Surfactants in Cosmetic Products
Published in Heather A.E. Benson, Michael S. Roberts, Vânia Rodrigues Leite-Silva, Kenneth A. Walters, Cosmetic Formulation, 2019
Ricardo Pedro, Kenneth A. Walters
The balance between the philic and phobic portions of a surfactant molecule dictates how (and if) the surfactant will behave as an emulsifier. The HLB (hydrophile–lipophile balance value) is an indication of its emulsification behaviour. In the HLB system, surfactants are classified according to their hydrophilicity.
Multi-strategic approaches for enhancing active transportation using self-emulsifying drug delivery system
Published in Journal of Drug Targeting, 2022
The HLB is a scale of 0–20 used to quantify the hydrophilic and lipophilic components of a surfactant; a measure of these values helps determine the function and application of surfactants in different types of emulsions. For instance, surfactants with HLB values of 6–18 are used for formulating oil in water nanoemulsions, whereas, 3.5–6 HLB valued surfactants are used when w/o emulsions are desired [23]. Long fatty acids with a high degree of esterification are high in lipophilicity and are said to have low HLB values [28]. However, the HLB theory does not study the geometry of the surfactants that forms a decisive element in the hydrophilicity and lipophilicity of the surfactants. Additionally, the lipid properties and interaction between surfactants and lipids is not considered. The HLB value of a surfactant consisting of ethylene oxide as the hydrophilic group is equal to the sum of the mass percentages of polyoxyethylene (E) and polyhydric alcohols (glycerol or sorbitol) (P) multiplied with 20 [23].
Lipid-based nanoformulations in the treatment of neurological disorders
Published in Drug Metabolism Reviews, 2020
Faheem Hyder Pottoo, Shrestha Sharma, Md. Noushad Javed, Md. Abul Barkat, Md. Sabir Alam, Mohd. Javed Naim, Ozair Alam, Mohammad Azam Ansari, George E. Barreto, Ghulam Md. Ashraf
SLNs have been introduced in the early 1990s and are recognized as a substitute for the conventional colloidal drug carriers, i.e. microparticles, liposomes, microemulsions, and nanoemulsions (Ali Khan et al. 2013; Ezzati Nazhad Dolatabadi and Omidi 2016). Instead of liquid lipid of emulsion systems, integration of solid lipids such as triglycerides (tri-stearin), fatty acids (stearic acid or palmitic acid), or waxes (cetylpalmitate) to constitute lipophilic core either to dissolve or disperse hydrophobic drugs, stabilization of systems by emulsifiers or stabilizing agents as well as their nanometric size (around 40–200 nm) range, solid lipid depression systems, i.e. SLNs are being considered as first-generation novel lipid drug carriers. The choice of surfactant and its suitability depends on its hydrophilic lipophilic balance (HLB) value as its ability to prevent aggregation of particles and induce changes in the SLN characteristics. The rate of SLN degradation depends on the type of surfactant used and can be modified by the change of surfactant (Üner and Yener 2007). Due to complete absence of liquid lipid as well as the presence of solid lipids only, SLNs are being considered as most stable and rigid in nature; however, this stability bearing some adverse consequences on polymorphism of drugs as well as their fate as well.
Enhancement of loading and oral bioavailability of curcumin loaded self-microemulsifying lipid carriers using Curcuma oleoresins
Published in Drug Development and Industrial Pharmacy, 2020
Umesh Kannamangalam Vijayan, Sadineni Varakumar, Sushant Sole, Rekha S. Singhal
The solubility of the drug is one of the factors that decide its oral bioavailability [33]. Among the various oleophilic systems tested, curcumin solubility was found to be maximum for ethyl oleate (3.46 ± 0.32 mg/mL; Table 1). Hence, ethyl oleate was taken further for the preparation of curcumin SMEDDS. Ethyl oleate is a food additive with approved GRAS status. Surfactants were also screened for evaluating the solubility of curcumin. Hydrophilic–lipophilic balance or HLB number indicates the ability of the surfactant to stabilize oil-in-water or water-in-oil emulsions and is a balance of the size and strength of the hydrophilic and lipophilic moieties present in the molecules. The efficiency of self-microemulsification is dependent on the HLB of the surfactant with surfactants of HLB 12–15 is regarded as the most efficient [36]. Hence, surfactants such as Tween 80 (HLB-15), Labrasol® (HLB-12) and Kolliphor® HS 15 (HLB 14-16) were screened for solubilization of curcumin. Co-surfactants used for the screening included ethanol, Transcutol® P, propylene glycol, and PEG 400. Co-surfactant reduces the interfacial tension and increases the solubility of the hydrophobic drug. Among the surfactants and co-surfactants screened, Tween 80 and Transcutol® P (TCP) showed maximum solubility (Table 1). Screening of oleoresins based on curcumin solubility showed that the C. aromatica oleoresins give higher solubility compared to oleoresins of M. fragrans, P. nigrum, and Z. officinale (Supporting Information file S2). C. longa oleoresin was taken as control.