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Lipid-based nano-delivery systems for skin delivery of drugs and bioactives.

Hua S - Front Pharmacol (2015)

View Article: PubMed Central - PubMed

Affiliation: The School of Biomedical Sciences and Pharmacy, The University of Newcastle Callaghan, NSW, Australia.

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Topical drug delivery across the skin can offer many advantages, such as confer sustained drug release, lower fluctuations in plasma drug levels, circumvent first-pass metabolism, improve patient compliance, and provide local (dermal), or systemic (transdermal) effects (Schäfer-Korting et al., ; El Maghraby et al., )... In general, the different experimental parameters such as formulation, experimental setting, species, gender, and age of skin donors, often make it challenging to compare similar studies (Geusens et al., )... Furthermore, diseased skin is often characterized by a reduce barrier function and an altered lipid composition and organization... Four general mechanisms have been reported, which include (i) intact drug-laden vesicle penetration into the different layers of the skin; (ii) lipid vesicles acting as penetration enhancers via their skin lipid-fluidizing property; (iii) direct carrier-skin drug exchange by “collision complex transfer” between the drug intercalated in the lipid bilayer and the surface phase of the stratum corneum; and (iv) lipid vesicle-mediated enhanced transdermal drug delivery via appendageal pathways (e.g., hair follicles and sweat ducts) (Dubey et al., ; Elsayed et al., ; El Maghraby et al., ; Nounou et al., ; El Maghraby and Williams, )... Liposomes offer many advantages as drug delivery carriers—for example they are biodegradable, non-toxic, and are able to encapsulate both water-soluble and lipophilic substances (Hua and Wu, ; Hua, ; Bozzuto and Molinari, )... They are similar to the epidermis with respect to their lipid composition, which enables them to penetrate the epidermal barrier to a greater extent compared to other conventional dosage forms... Their use in topical formulations have demonstrated improved treatment of inflammatory skin conditions such as atopic dermatitis, psoriasis and acne; pathological conditions of peripheral tissue such as inflammatory pain, melanoma, and wound healing; and transdermal delivery of systemic agents for vaccinations and conditions such as diabetes (insulin delivery) and hormone replacement therapy (estrogen delivery) (Elsayed et al., ; Schäfer-Korting et al., ; El Maghraby et al., ; Geusens et al., )... Based on recent findings, it has been demonstrated that conventional liposomes are of little or no value as carriers for transdermal drug delivery, as they tend to remain confined to upper layers of the stratum corneum and are not able to penetrate into the granular layers of the epidermis (Kirjavainen et al.,, ; Honeywell-Nguyen and Bouwstra, ; Cosco et al., ; Geusens et al., )... Conventional liposomes have shown increased effectiveness for local dermal drug delivery across intact skin in comparison to free drug, with the ability to provide prolonged drug release (Hua and Wu, )... For example, topical application of loperamide HCl-encapsulated liposomal gel, resulted in potent and prolonged analgesic and anti-inflammatory activity in a rodent model of acute inflammatory pain compared to controls (which did not show any therapeutic effects) (Iwaszkiewicz and Hua, )... The newer classes of lipid vesicles, including deformable lipid vesicles and surfactant-based elastic vesicles, have generated improved in vivo and in vitro skin delivery of various drugs and bioactive agents for both dermal and transdermal drug delivery (Elsayed et al., ; Schäfer-Korting et al., ; El Maghraby et al., ; Geusens et al., )... Studies focused on the nanotoxicology of these delivery systems in human skin have been limited, especially with the newer classes, and is likely to vary according to the composition and size of the vesicles... For example, there is a need to evaluate the short-term and long-term effects of repeated applications of formulations containing relatively high concentrations of ethanol or surfactants on the skin... As the preparation of the newer classes of lipid vesicles involves similar methods to those used in the preparation of conventional liposomes, this has made the large-scale manufacturing and evaluation of such products less challenging... Although innovative and efficient, translation of these types of drug delivery systems to the clinic would need to show significant therapeutic advantage over existing therapeutic strategies, due to the added costs required in the manufacturing process.

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Schematic representation of the different types of lipid-based vesicular delivery systems. (A) Conventional liposomes generally consist of a lipid bilayer composed of phospholipids and cholesterol, which encloses an aqueous core. Both the lipid bilayer and the aqueous space can incorporate hydrophobic or hydrophilic compounds, respectively (Hua and Wu, 2013). Liposome characteristics can be modified by the addition of surfactants to form (B) Transfersomes® and (C) niosomes (depending on the ratio of phospholipid to surfactant), or relatively high concentrations of ethanol to form (D) ethosomes (Geusens et al., 2011; Vanic, 2014).
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Figure 1: Schematic representation of the different types of lipid-based vesicular delivery systems. (A) Conventional liposomes generally consist of a lipid bilayer composed of phospholipids and cholesterol, which encloses an aqueous core. Both the lipid bilayer and the aqueous space can incorporate hydrophobic or hydrophilic compounds, respectively (Hua and Wu, 2013). Liposome characteristics can be modified by the addition of surfactants to form (B) Transfersomes® and (C) niosomes (depending on the ratio of phospholipid to surfactant), or relatively high concentrations of ethanol to form (D) ethosomes (Geusens et al., 2011; Vanic, 2014).

Mentions: Liposomes are well-established nano-sized lipid-vesicles that offer potential value in topical drug delivery. They are formed by one or multiple lipid bilayers that enclose a discrete aqueous phase (Figure 1). Liposomes offer many advantages as drug delivery carriers—for example they are biodegradable, non-toxic, and are able to encapsulate both water-soluble and lipophilic substances (Hua and Wu, 2013; Hua, 2014; Bozzuto and Molinari, 2015). They are similar to the epidermis with respect to their lipid composition, which enables them to penetrate the epidermal barrier to a greater extent compared to other conventional dosage forms. The majority of topically applied liposomes onto the skin will accumulate in the upper layers of the stratum corneum and function more as a “reservoir” providing a more localized action (Kirjavainen et al., 1999; Honeywell-Nguyen and Bouwstra, 2005; Cosco et al., 2008; Geusens et al., 2011).


Lipid-based nano-delivery systems for skin delivery of drugs and bioactives.

Hua S - Front Pharmacol (2015)

Schematic representation of the different types of lipid-based vesicular delivery systems. (A) Conventional liposomes generally consist of a lipid bilayer composed of phospholipids and cholesterol, which encloses an aqueous core. Both the lipid bilayer and the aqueous space can incorporate hydrophobic or hydrophilic compounds, respectively (Hua and Wu, 2013). Liposome characteristics can be modified by the addition of surfactants to form (B) Transfersomes® and (C) niosomes (depending on the ratio of phospholipid to surfactant), or relatively high concentrations of ethanol to form (D) ethosomes (Geusens et al., 2011; Vanic, 2014).
© Copyright Policy
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC4588690&req=5

Figure 1: Schematic representation of the different types of lipid-based vesicular delivery systems. (A) Conventional liposomes generally consist of a lipid bilayer composed of phospholipids and cholesterol, which encloses an aqueous core. Both the lipid bilayer and the aqueous space can incorporate hydrophobic or hydrophilic compounds, respectively (Hua and Wu, 2013). Liposome characteristics can be modified by the addition of surfactants to form (B) Transfersomes® and (C) niosomes (depending on the ratio of phospholipid to surfactant), or relatively high concentrations of ethanol to form (D) ethosomes (Geusens et al., 2011; Vanic, 2014).
Mentions: Liposomes are well-established nano-sized lipid-vesicles that offer potential value in topical drug delivery. They are formed by one or multiple lipid bilayers that enclose a discrete aqueous phase (Figure 1). Liposomes offer many advantages as drug delivery carriers—for example they are biodegradable, non-toxic, and are able to encapsulate both water-soluble and lipophilic substances (Hua and Wu, 2013; Hua, 2014; Bozzuto and Molinari, 2015). They are similar to the epidermis with respect to their lipid composition, which enables them to penetrate the epidermal barrier to a greater extent compared to other conventional dosage forms. The majority of topically applied liposomes onto the skin will accumulate in the upper layers of the stratum corneum and function more as a “reservoir” providing a more localized action (Kirjavainen et al., 1999; Honeywell-Nguyen and Bouwstra, 2005; Cosco et al., 2008; Geusens et al., 2011).

View Article: PubMed Central - PubMed

Affiliation: The School of Biomedical Sciences and Pharmacy, The University of Newcastle Callaghan, NSW, Australia.

AUTOMATICALLY GENERATED EXCERPT
Please rate it.

Topical drug delivery across the skin can offer many advantages, such as confer sustained drug release, lower fluctuations in plasma drug levels, circumvent first-pass metabolism, improve patient compliance, and provide local (dermal), or systemic (transdermal) effects (Schäfer-Korting et al., ; El Maghraby et al., )... In general, the different experimental parameters such as formulation, experimental setting, species, gender, and age of skin donors, often make it challenging to compare similar studies (Geusens et al., )... Furthermore, diseased skin is often characterized by a reduce barrier function and an altered lipid composition and organization... Four general mechanisms have been reported, which include (i) intact drug-laden vesicle penetration into the different layers of the skin; (ii) lipid vesicles acting as penetration enhancers via their skin lipid-fluidizing property; (iii) direct carrier-skin drug exchange by “collision complex transfer” between the drug intercalated in the lipid bilayer and the surface phase of the stratum corneum; and (iv) lipid vesicle-mediated enhanced transdermal drug delivery via appendageal pathways (e.g., hair follicles and sweat ducts) (Dubey et al., ; Elsayed et al., ; El Maghraby et al., ; Nounou et al., ; El Maghraby and Williams, )... Liposomes offer many advantages as drug delivery carriers—for example they are biodegradable, non-toxic, and are able to encapsulate both water-soluble and lipophilic substances (Hua and Wu, ; Hua, ; Bozzuto and Molinari, )... They are similar to the epidermis with respect to their lipid composition, which enables them to penetrate the epidermal barrier to a greater extent compared to other conventional dosage forms... Their use in topical formulations have demonstrated improved treatment of inflammatory skin conditions such as atopic dermatitis, psoriasis and acne; pathological conditions of peripheral tissue such as inflammatory pain, melanoma, and wound healing; and transdermal delivery of systemic agents for vaccinations and conditions such as diabetes (insulin delivery) and hormone replacement therapy (estrogen delivery) (Elsayed et al., ; Schäfer-Korting et al., ; El Maghraby et al., ; Geusens et al., )... Based on recent findings, it has been demonstrated that conventional liposomes are of little or no value as carriers for transdermal drug delivery, as they tend to remain confined to upper layers of the stratum corneum and are not able to penetrate into the granular layers of the epidermis (Kirjavainen et al.,, ; Honeywell-Nguyen and Bouwstra, ; Cosco et al., ; Geusens et al., )... Conventional liposomes have shown increased effectiveness for local dermal drug delivery across intact skin in comparison to free drug, with the ability to provide prolonged drug release (Hua and Wu, )... For example, topical application of loperamide HCl-encapsulated liposomal gel, resulted in potent and prolonged analgesic and anti-inflammatory activity in a rodent model of acute inflammatory pain compared to controls (which did not show any therapeutic effects) (Iwaszkiewicz and Hua, )... The newer classes of lipid vesicles, including deformable lipid vesicles and surfactant-based elastic vesicles, have generated improved in vivo and in vitro skin delivery of various drugs and bioactive agents for both dermal and transdermal drug delivery (Elsayed et al., ; Schäfer-Korting et al., ; El Maghraby et al., ; Geusens et al., )... Studies focused on the nanotoxicology of these delivery systems in human skin have been limited, especially with the newer classes, and is likely to vary according to the composition and size of the vesicles... For example, there is a need to evaluate the short-term and long-term effects of repeated applications of formulations containing relatively high concentrations of ethanol or surfactants on the skin... As the preparation of the newer classes of lipid vesicles involves similar methods to those used in the preparation of conventional liposomes, this has made the large-scale manufacturing and evaluation of such products less challenging... Although innovative and efficient, translation of these types of drug delivery systems to the clinic would need to show significant therapeutic advantage over existing therapeutic strategies, due to the added costs required in the manufacturing process.

No MeSH data available.