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Spray-freeze-dried Particles as Novel Delivery Systems for Vaccines and Active Pharmaceutical Ingredients
Published in S. Padma Ishwarya, Spray-Freeze-Drying of Foods and Bioproducts, 2022
The efficacy of aforesaid methods/devices of transdermal delivery is limited by physical (hydrophobicity of stratum corneum) and chemical (presence of multiple enzyme types in the epidermal layer) barriers. Various physical modifications have been carried out to enhance the permeability of molecules through the skin layers, listed as follows: (1) thermal ablation; (2) iontophoresis (applying local electric current to deliver ionic therapeutic compounds into the systemic circulation); (3) sonophoresis (usage of ultrasound to enhance the absorption of topical compounds through the different layers of skin); (4) electroporation (generating small pores on the surface of stratum corneum using pulse voltage) and (5) microneedles (Fig. 8.12). Chemical penetration enhancers like dimethylsulfoxide (DMSO) or Azone, oleic acid, ethanol, propylene glycol, menthol and limonene are also used to enhance drug permeability. Nevertheless, both physical and chemical enhancers need to be used at high dose or high potency to achieve their intended purpose. But, this can lead to skin irritation and affect the skin barrier function.
Recent Nanotechnological Advancements in Delivery of Peptide and Protein Macromolecules
Published in Pradipta Ranjan Rauta, Yugal Kishore Mohanta, Debasis Nayak, Nanotechnology in Biology and Medicine, 2019
Penetration enhancers are employed to enhance the passage of a pharmacologically active quantity of peptide or protein through the mucosal membranes and can be classified into five categories (Table 11.1). Although the complete mechanism of penetration enhancement is still unclear, some of the prominent ways through which the penetration enhancers carry out their function are by altering the structures/properties of mucosal membranes; by altering the thermodynamic activity of proteins and peptides; and by protecting peptides and proteins from proteolytic activity. Although most of the penetration enhancers act by disordering the membrane integrity, not enough information about the correlation between the efficacy and the degree of change/damage to membrane cells with their use is available (Lee and Yamamoto, 1989). Also, penetration enhancers may cause irreversible undetermined biochemical change at the site of effect. Practically, their chronic use may impart toxicity by causing them to absorb themselves. The efficacy of penetration enhancers is determined by the type and characteristics of the protein and penetration enhancer, the administration site, and the delivery system.
Transdermal Drug Delivery Systems
Published in Ambikanandan Misra, Aliasgar Shahiwala, In-Vitro and In-Vivo Tools in Drug Delivery Research for Optimum Clinical Outcomes, 2018
In passive methods dosage forms have been developed and/or tailored to augment the diffusion of drug and/or enhance their permeability across the skin. These methods include the use of penetration enhancers (Williams and Barry 2004), supersaturated systems (Pellet et al. 2003), prodrugs or metabolic approaches (van Heerden et al. 2010; Tsai et al. 1996), liposomes, and other vesicles or nanocarriers (Honeywell and Bouwstra 2005; Trotta 2004; Escobar-Chávez et al. 2012; Shakeel and Ramadan 2010). However, these methods cannot lead to significant changes in the barrier properties of the skin, and thus, the number of drugs which can penetrate are limited. The passive methods do not involve the application of external forces on the skin to manipulate its barrier properties, while active methods use external forces to overcome the barriers. These are useful for low molecular weight drug molecules with poor aqueous solubility and permeability and also improve the dose control, patient acceptance and compliance in comparison to semisolid formulations. Penetration enhancers can increase the permeability of the skin. The classification of different penetration enhancers with their examples are summarized in Table 3.3 (Dragicevic et al. 2015; Escobar-Chávez et al. 2012).
Nanoemulsion-based patch for the dermal delivery of ascorbic acid
Published in Journal of Dispersion Science and Technology, 2022
Ahlam Zaid Alkilani, Rania Hamed, Ghaid Hussein, Sabreen Alnadi
Different mechanisms can be pointed out to justify the ex vivo results such as the maintaining close contact between the polymeric matrix of F1 and SC over the entire application, where patch-skin contact, for prolonged period of time, is essential to improve the permeation of AA across the skin.[63] In addition to the attracted properties of the AA nanoemulsion including the nano-sized droplets which provide a large surface to volume ratio and presence of oil, surfactant, and cosurfactant as penetration enhancers,[48] the presence of PEG 400, which is used as plasticizer in F1, may further improve the penetration of AA.[59] These penetration enhancers may act by disturbing the SC lipid mortar, decreasing the diffusion barrier of the skin, increasing the hydration of SC, and providing the fluidization of the lipid matrix.[42] All these factors can occur simultaneously and synergistically, providing the results found in this work.
The impact of formulation variables on the optimization of pilot scale clobetasol 17-propionate creams
Published in Cogent Engineering, 2020
Ayeshah Fateemah Beebee Fauzee, Roderick Bryan Walker
Formulating a semi-solid pharmaceutical product is technically challenging due to potential stability issues and the use of appropriate surfactants may enhance the stability of topical products dramatically of used at appropriate concentrations (Sheikh et al., 2011). Gelot® 64 is an oil-in-water emulsifying agent that is a mixture of glyceryl stearate and polyethylene glycol-75 stearate (PEG-75 stearate) and functions as a surfactant, solubilizer, thickening agent, emollient, spreading agent, wetting agent, and dispersant in cosmetic and pharmaceutical formulations (Fauzee, 2011). Glyceryl monostearate acts as a self-emulsifying system that usually produces satisfactory o/w emulsions as it is a mixture of monoacylglycerols that consist mainly of monostearoylglycerol, with variable amounts of di- and tri-acylglycerols (Ballmann & Mueller, 2008). Cetostearyl alcohol is a mixture of solid aliphatic alcohols that is used as a stiffening agent and/or emulsion stabilizer in cream, ointment, and other topical preparations (Fauzee, 2011). Skin penetration enhancers are critical to improve the partitioning of an Active Pharmaceutical Ingredient (API) into the stratum corneum thereby facilitating drug transport into and through the skin. Formulation scientists may add additional non-volatile, water-miscible co-solvents such as propylene glycol into cream formulations to further enhance the permeation process. In this way evaporation of components of a formulation occurs leaving a film with a high concentration of API on the skin surface further increasing the concentration gradient and facilitation of drug delivery. The cream, therefore, deposits lipids and other moisturizers on and into the horny layer of the skin, increasing and/or restoring hydration of the tissues (Walker & Smith, 1996).
Design and development of raw clay-based formulations emulsions loaded with ascorbyl glucoside, in vitro evaluations on topical delivery and cell viability
Published in Journal of Dispersion Science and Technology, 2023
Jemima Daniela Shultz, Gislaine Ricci Leonardi, Silvana Raquel Alina Bertolino, Silvia Lucia Cuffini, Hana Mohd, Amanda Costa Caritá, Wanilson Luiz-Silva, Parinbhai Shah, Wilma Gladis Ticona Chambi, Bozena Michniak-Kohn
In this study it was observed that SP, SW and W4 clays all played a role as penetration enhancers for the formulations tested. Usually, penetration enhancers act by lipid disruption and interact with the stratum corneum intercellular lipid domain and its organization resulting in making the skin more permeable.[41] Understanding the physiochemical relationship of active/vehicle interactions through a membrane barrier is critical for selection of optimal formulation penetration enhancement efficacy.[42]