Liposomes cosmetic formulations

The selective quantification of different degradation products makes P NMR spectroscopy the ideal method for testing the stability of liposome-containing formulations in pharmaceutical or cosmetic products (Fig. 4.22). 

The main objective of this volume is to demonstrate the importance of the fundamental aspects of interfadal phenomena in various industrial applications. For this purpose 1 have chosen five different topics which are described in five parts. The first part deals with cosmetics and personal care formulations. Several cosmetic formulations can be identified lotions, hand creams (cosmetic emulsions), nanoemulsions, multiple emulsions, liposomes, shampoos and hair conditioners, sunscreens and color cosmetics. The formulation of these complex multiphase systems requires understanding the colloidal forces that eire responsible for their preparation, stabilization and application. The fundamental principles that are responsible for the formulation of the cosmetic formulations must be considered. 

This section, which is by no means exhaustive, will deal with the following topics (i) Surfactants used in cosmetic formulations, (il) Interaction forces between particles or droplets in a dispersion and their combination, (iil) Description of stability in terms of the interaction forces, (iv) Self-assembly structures and their role in stabilization, skin feel, moisturization and delivery of actives, (v) Use of polymeric surfactants for stabilization of nanoemulsions, multiple emulsions, liposomes and vesicles. 

From a formulative point of view, it is important to take into consideration that the base in which liposomes are incorporated could also affect the drug delivery profile as well as the interactions between the liposomes and skin structures. The effect of formulation bases on dyphylline skin permeation from liposomes was examined by Touitou et al. [9]. In this work the effect of four bases for dyphylline liposomes (polyethylene glycol (PEG), carbopol gel, a PEG-enhancer base, and water) was studied. With these bases, the lowest skin permeation flux and a superior skin partitioning of liposomal dyphylline were reported for the PEG base, suggesting that this base favored dyphylline accumulation within the skin. A number of liposomes are currently marketed by cosmetic raw material companies for incorporation in different bases to obtain final products. It is important to keep in mind that the delivery properties of the final formulation could be altered by the vehicle used and should be tested to confirm any performance characteristics claimed. 

Cosmetic creams and lotions may be formulated with ingredient designed to penetrate the outer layer of the skin (the stratum corneum), or explicitly not to enter this layer. Liposomes can be a useful means of delivering selected chemical species since they form lamellar liquid crystalline structures on the surface of skin, do not disrupt the outermost layer of skin and therefore do not cause skin irritation [236]. See also Section 14.2 on vesicles and drug delivery. 

Liposomes have been used for years as components of drug delivery systems, and as transdermal carriers of active ingredients in the cosmetic industry (307, 308). More recently, liposomes have found use in the food and nutritional supplement industries. Keller (308) lists more than a dozen nutritional products on the market that have been formulated with novel liposome-based delivery systems. In the food area, hposomes have been studied for their ability to encapsulate and provide controlled release of enzymes (309, 310), and liposome-encapsulated enzymes have been used to accelerate the ripening of cheese (311). 

Vineland, NJ) or over-the-counter cosmetic creams promoted for improved hydration (L Oreal, Paris and Dior, Paris). More recently, parenteral liposome formulations of amphotericin B, doxorubicin, and dau-norubicin have been approved and marketed (ABELCET, Elan, the Liposome Co., Inc, Princeton, NJ AmBisome and DaunoXome, Nexstar/Fujisawa, Deerfield Park, IL Amphotec and Doxil, Sequus/ Alza, Menlo Park, CA), with others on the horizon for applications in photodynamic therapy. Although the vast majority of liposome preparations are constructed from phospholipids, other nonphospholipid materials can be used either alone or in mixtures to form bilayer arrays. One such example is Amphotec, which utilizes sodium cholesteryl sulfate as the primary lipid. Other liposome forming materials may include but are not limited to fatty-acid compositions, ionized fatty acids, or fatty acyl amino acids, longchain fatty alcohols plus surfactants, ionized lysophospholipids or combinations, non-ionic or ionic surfactants and amphiphiles, alkyl maltosides, a-tocopherol esters, cholesterol esters, polyoxyethylene alkyl ethers, sorbitan alkyl esters, and polymerized phospholipid compositions. ° ... 

Trehalose is used for the lyoprotection of therapeutic proteins, particularly for parenteral administration. Other pharmaceutically relevant applications include use as an excipient for diagnostic assay tablets for stabilization during the freeze-thaw and lyophilization of liposomes and for stabilization of blood cells,cosmetics, and monoclonal antibodies. Trehalose may also be used in formulations for topical application. ... 

Recent findings combining liposomal structures and surfactant formulations in pharmaceuticals and cosmetics seem to open thrilling new possibilities. 

J, du Plessis. K. Egbaria. and N. Weiner, Influence of formulation factors on the disposition of liposomal components into the different strata of the sktn. J. Soc. Cosmet. Chem. 43 (1992) 93-100-... 

Liposomes have particular application in the formulation of medicaments and cosmetics. One of the more recent developments has been their application as formultion aids for pesticides where recent patents have been granted C5] and this will serve as a useful example of how natural surfactants can be utilised in an industrial application. 

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