Pantelic Alkyl Polyglucosides

From Natural-origin Surfactants to Prospective Delivery Systems
1. Auflage 2014
ISBN: 978-1-908818-77-5
Verlag: Elsevier Science & Techn.
Format: EPUB
Kopierschutz: Adobe DRM (»Systemvoraussetzungen)

E-Book, Englisch, Band 0, 208 Seiten

Reihe: Woodhead Publishing Series in Biomedicine

The on-going 'green' trend in the personal care industry coupled with global environmental concerns, place natural-origin, biodegradable and skin-friendly surfactants such as alkyl polyglucosides (APGs) in high demand. After successful use in cosmetics, sufficient data has been obtained to welcome some sugar emulsifiers into the field of drug dosage. Alkyl Polyglucosides presents a comprehensive compendium which guides a researcher from the APG-related preformulation stages to formulation processing, including the investigation of various APG-stabilized systems skin performance. This book introduces various APG representatives, their benefits in relation to certain conventional surfactants, physicochemical and interfacial properties, possible interaction with commonly used ingredients and diverse characterization techniques indispensable for the assessment of colloidal systems. The first chapter introduces alkyl polyglucosides, followed by chapters on their properties, behaviour, an overview of the patent protection mechanisms and guidelines for submitting patent applications. Finally, a conclusion surveys international patent applications involving APGs. - Introduces the field of alkyl polyglucoside emulsifiers, listing all the contemporary and newly synthesized APG emulsifiers - Provides detailed information on various aspects of APG-based structures - Reveals potential of APG-stabilized vehicles as prospective delivery systems using several model drugs and cosmetic actives - Includes an up-to-date review of research conducted in the field of APGs, facilitating future preformulation and formulation studies for researchers - Offers a concise and practical compendium of characterization techniques

Autoren/Hrsg.

Pantelic, Ivana

Inhaltsverzeichnis

1;Cover
;1
2;Alkyl Polyglucosides : From natural-origin surfactants to prospective delivery systems
;4
3;Copyright
;5
4;Contents;6
5;List of figures and tables
;10
5.1;Figures;10
5.2;Tables;13
6;About the authors;14
7;1:
Alkyl Polyglucosides: An emerging class of sugar surfactants;18
7.1;1.1 Introduction;18
7.2;1.2 Environmental evaluation of APGs;25
7.3;1.3 References;32
8;2:
Behind the Alkyl Polyglucosidebased structures: Lamellar liquid crystalline and lamellar gel phases in different emulsion system;38
8.1;2.1 Introduction;39
8.2;2.2 Alkyl Polyglucosides;41
8.3;2.3 Physicochemical properties of APGs;43
8.4;2.4 General considerations on APGs’ safety profile
;50
8.5;2.5 Lamellar mesophase stabilized emulsion systems;51
8.6;2.6 References;65
9;3:
Towards Alkyl Polyglucosidestabilized formulations: Influence of some common excipients ;70
9.1;3.1 Introduction;70
9.2;3.2 Addition of other stabilizers (cosurfactants, costabilizers);71
9.3;3.3 Components of the oil phase;73
9.4;3.4 Cosolvents and potential penetration enhancers;78
9.5;3.5 Concluding remarks;85
9.6;3.6 References;86
10;4:
Emulsion systems: From stability concerns to sensory properties;90
10.1;4.1 Introduction;90
10.2;4.2 Rheology;92
10.3;4.3 Textural analysis;93
10.4;4.4 Sensory evaluation;94
10.5;4.5 Case study I : Change of one component in the oil phase of a water in oil emulsion
;96
10.6;4.6 Case study II : Change of the oil phase in simple ternary oil in water emulsion systems
;106
10.7;4.7 Case study III : Change of the active substance in the oil in water emulsion systems
;113
10.8;4.8 Concluding remarks;119
10.9;4.9 References;120
11;5:
Alkyl Polyglucosidebased delivery systems: In vitro/in vivo skin absorption assessment;124
11.1;5.1 Introduction;125
11.2;5.2 In vitro enhancer and diffusion cells;127
11.3;5.3 In vivo tape stripping technique;136
11.4;5.4 In vivo skin blanching assay;143
11.5;5.5 Concluding remarks;146
11.6;5.6 References;146
12;6:
Objective skin performance evaluation: How mild are APGs to the skin?;152
12.1;6.1 Introduction;153
12.2;6.2 The skin performances of APGs: safety and efficacy considerations
;155
12.3;6.3 How to assess efficacy and skin irritation potential of APG-based emulsions: methods
;158
12.4;6.4 Concluding remarks;172
12.5;6.5 References;173
13;7:
International patent protection of Alkyl Polyglucosides;180
13.1;7.1 Introduction;181
13.2;7.2 An overview of the patent protection mechanisms at international and regional levels;182
13.3;7.3 Recent case law relating to the patent protection of Alkyl Polyglucosides;188
13.4;7.4 Concluding remarks;195
13.5;7.5 References;196
14;Index;198

Leseproben

2 Behind the Alkyl Polyglucoside-based structures: Lamellar liquid crystalline and lamellar gel phases in different emulsion systems
Snezana Savic, Ivana Pantelic, Milica Lukic, Bojan Markovic and Jela Milic,     University of Belgrade, Serbia Abstract:
Surfactants play an important role in the development of colloidal delivery systems for cosmetics and pharmaceutical ingredients. Alkyl Polyglucosides (APGs) show peculiar physicochemical behaviour, which affects their interfacial properties. For example, the phase behaviour of APG/water systems is only slightly influenced by temperature. Hence, no temperature-dependent phase inversion occurs in APG-containing emulsions. They may form thermotropic liquid crystalline phases on heating, and lyotropic liquid crystalline phases on addition of a solvent. In lyotropic liquid crystals, increasing alkyl chain length leads to destabilization of the hexagonal phase in favour of the lamellar one, which is interesting for pharmaceutical systems. The addition of fatty alcohol to APG/water mixtures leads to the appearance of different lamellar phases. Characteristics of APG-mediated systems will be discussed in this chapter. Key words APG adsorption and clouding behaviour APG interfacial properties critical micelle concentration lamellar liquid crystalline phases lamellar mesophases micelle shape stabilized delivery systems 2.1 Introduction
As is well known, surfactants show interesting interfacial and bulk properties (Geetha and Tyagi, 2012) and have a wide variety of uses (Paul and Moulik, 2001). If one excludes other potential purposes, surfactants are one of the most exploited raw materials in the formulation of versatile cosmetic products, but also one of the most important classes of pharmaceutical excipients, finding a wide range of uses in pharmaceutical preparations. Depending on the type of formulation, surfactants may play a role in solubilization or stabilization of cosmetic actives/drugs in different liquid preparations, improve physical stability and textural characteristics of emulsion systems and semisolids, or alter the flow properties of powders and granulates in the manufacturing of solid cosmetics or pharmaceutical dosage forms (Corrigan and Healy, 2002). Moreover, surfactants play an important role in the development of colloidal delivery systems for cosmetics and active pharmaceutical ingredients (APIs), such as reverse micelles, vesicles, liquid crystal dispersions, nanoemulsions and nanoparticles (Müller-Goymann, 2004). In addition, surfactants strongly affect biological membranes, changing their permeability and thus, for instance, influencing the penetration of drugs and cosmetic actives into the skin. This behaviour is strongly related to surfactants’ safety profiles, as they also have the capacity to irritate the skin and damage biological membranes (Savic et al., 2010). Although this phenomenon is mainly concentration-dependent, it is particularly related to the so-called traditional/conventional surfactants/emulsifiers. For example, if one considers the field of dosage forms/drug delivery systems design, though a large number of commercial surfactants are available, a proportionally small group of them are approved as pharmaceutical excipients, and therefore widely accepted by the pharmaceutical industry. From this group, surfactants of particular pharmaceutical importance include anionic sodium lauryl sulphate (SLS/SDS) and non-ionic polyoxyethylated glycol monoethers (e.g. cetomacrogol), sorbitan esters (Span®) and ethoxylated sorbitan esters or polysorbates (Tween®) (DAB 2006; BP 2009; Ph. Eur. 7; USP/NF 35). In fact, it could be said that a whole series of potential uses of surfactants could be perfectly covered by the conventional representatives. However, increased attention given to the environment over the past few decades has produced a growing interest in the field of the so-called natural surfactants. This term relates, in its broadest sense, to surface-active substances coming from natural raw materials. Generally, there are three categories of natural surfactants: amphiphiles produced by yeast or bacteria, amphiphiles containing a natural polar headgroup, and amphiphiles containing a natural hydrophobic tail. Sugars and amino acids are the two most important examples of surfactant polar headgroups of natural origin (Holmberg, 2001; Johansson and Svensson, 2001;Stubenrauch, 2001). As well as the awareness of environmental protection, there is an increase in demand for natural products, already elaborated in the previous chapter. Still, the range of surfactants suitable for the formulation of authentic natural cosmetics is quite limited (Alkyl Glucosides, Alkyl Glutamates, Alkyl Citrates, Alkyl Lactylates, Alkyl Sulphates, Alkyl Tartrates, protein derivatives, soaps, natural betaines or saponins), according to the standards of non-governmental organizations (NGOs) such as NaTrue (The International Natural and Organic Cosmetic Association), BDIH (Bundersverband der Industrie- und Handelsunternehmen) and COSMOS (cosmetic organic and natural standard). To be part of a natural cosmetic product, all ingredients (including surfactants) should be evaluated not only with respect to their origin, but also taking into account other criteria, such as the applied manufacturing process, by-products, preservation systems, biological degradation and aquatic toxicity (Hauthal, 2012). Although there are certain surfactants that are accepted by all the organizations mentioned, there are still some differences regarding their acceptance criteria. From the aforementioned it is clear that Alkyl Polyglucosides (APGs), also known as Alkyl Glucosides, could be safely used as primary/basic surfactants as well as co-surfactants in the formulation of those cosmetic products declared as natural. Indeed, APGs are commonly defined as a newer class of so-called natural, polyethylene glycol (PEG)-free surfactants, produced from renewable resources (von Rybinski and Hill, 1998;Holmberg, 2001; Stubenrauch, 2001; Tasic-Kostov et al., 2011a). In this vein, their biodegradability, accompanied by their natural origin, means they could be considered as the most important sugar-based surfactants today (Tasic-Kostov et al., 2011a). There is a strong interest in exploring APGs as surfactants for several types of application, since they are multifunctional substances that have proved to be very efficient in different cleaning products. There are also certain indications that some of them could be used as food emulsifiers (Tasic-Kostov et al., 2011a). On the other hand, APGs were studied as prospective surfactants/emulsifiers for emulsion systems stabilized with lamellar phases of liquid crystalline (La) and/or gel crystalline (Lß) type with high potential for skin moisturization, which could be a useful property for both cosmetic and pharmaceutical products (Savic et al., 2004; Savic et al., 2005a; Savic et al., 2005b; Savic et al., 2006; Savic et al., 2007; Savic et al., 2008a; Savic et al., 2008b; Savic et al., 2009a; Savic et al., 2009b; Savic et al., 2010; Tasic-Kostov et al., 2010; Kovacevic et al., 2011; Savic et al., 2011; Tasic-Kostov et al., 2011a; Tasic-Kostov et al., 2011b; Jaksic et al., 2012; Tasic-Kostov et al., 2012; Lukic et al., 2013). Therefore, APGs will be the focus of this chapter as structure-dependent promoters of lamellar mesophases. The chapter will provide crucial information on their physicochemical characteristics as well. 2.2 Alkyl Polyglucosides
APGs are a group of surfactants derived from natural sources, becoming widely known for their unique properties as compared with petrolatum-based surfactants (Geetha and Tyagi, 2012). They are a new generation of highly effective non-ionic carbohydrate-derived surfactants, low in toxicity, ecologically safe and made at low cost from renewable resources, having interesting interfacial properties (Hill, 2008; Geetha and Tyagi, 2012). In contrast to the other surfactants, many of the technical properties of the APGs are outstanding (Balzer and Luders, 2000). They have some surprising structural similarities to the glycolipids and other biological structures, and are hence frequently referred to as green surfactants. Taking into account their carbohydrate nature as well as their physiological and dermatological acceptability, APGs have been primarily used in the detergent, food, cosmetic and pharmaceutical industry, and are therefore candidates to be widely applied in the formulation of personal care and skin care products as well as in various types of pharmaceutical dosage forms, both conventional and advanced, nanosized delivery systems (Savic et al., 2010; Geetha and Tyagi, 2012). In addition, they are attractive for catalysis and adsorption applications, nanotechnology, analytical separation, biotechnology, ecological lubricants, environmental remediation and improved oil recovery (Adamezak et al., 1999; Geetha and Tyagi, 2012)....