Unsaturated fatty acids lactose esters: cytotoxicity, permeability enhancement and antimicrobial activity

Sugar based surfactants conjugated with fatty acid chains are an emerging broad group of highly biocompatible and biodegradable compounds with established and potential future applications in the pharmaceutical, cosmetic and food industries. In this work, we investigated absorption enhancing and antimicrobial properties of disaccharide lactose, mono-esterified with unsaturated fatty acids through an enzymatic synthetic approach. After chemical and cytotoxicity characterizations, their permeability enhancing activity was demonstrated using intestinal Caco-2 monolayers through transepithelial electrical resistance (TEER) and permeability studies. The synthesised compounds, namely lactose palmitoleate (URB1076) and lactose nervonate (URB1077), were shown to exhibit antimicrobial activity versus eight pathogenic species belonging to Gram-positive, Gram-negative microorganisms and fungi

Dizajn, razvoj i vrednovanje novih nanoemulzija za transdermalnu primjenu celekoksiba

The aim of the present study was to investigate the potential of nanoemulsion formulations for transdermal delivery of celecoxib (CXB). The in vitro skin permeation profile of optimized formulations was compared with CXB gel and nanoemulsion gel. Significant increase in the steady state flux (Jss), permeability coefficient (Kp) and enhancement ratio (Er) was observed in nanoemulsion formulations T1 and T2 (p < 0.05). The highest value of these permeability parameters was obtained in formulation T2, which consisted of 2% m/m of CXB, 10% m/m of oil phase (Sefsol 218 and Triacetin), 50% m/m of surfactant mixture (Tween-80 and Transcutol-P) and 40% m/m of water. The anti-inflammatory effects of formulation T2 showed a significant increase (p < 0.05) in inhibition after 24 h compared to CXB gel and nanoemulsion gel on carrageenean-induced paw edema in rats. These results suggested that nanoemulsions are potential vehicles for improved transdermal delivery of CXB.U radu su opisana ispitivanja nanoemulzija za transdermalnu primjenu celekoksiba (CXB). Profil permeacije kroz kožu ispitivan je in vitro i uspoređivan sa CXB gelom i nanoemulzijskim gelom. U formulacijama T1 i T2 postignuto je značajno povećanje ustaljenog fluksa (Jss), koeficijenta permeabilnosti (Kp) i povećanje omjera (Er) (p < 0.05). Najveće vrijednosti parametara permeabilnosti dobivene su u formulaciji T2 koja je sadržala 2% m/m CXB, 10% m/m uljne faze (Sefsol 218 i Triacetin), 50% m/m površinski-aktivnih tvari (Tween-80 i Transcutol-P) i 40% m/m vode. Protuupalno djelovanje formulacije T2 na edem šape štakora uzrokovan karageninom značajno je povećano (p < 0.05) poslije 24 h u usporedbi sa CXB gelom i nanoemulzijskim gelom. Rezultati ukazuju na poboljšanu isporuku celekoksiba putem nanoemulzija

Water Solubilization Using Nonionic Surfactants from Renewable Sources in Microemulsion Systems

In this study the effect of temperature, NaCl and oils (hydrocarbons: C8–C16) on the formation and solubilization capacity of the systems of oil/monoacylglycerols (MAG):ethoxylated fatty alcohols (CEO20)/propylene glycol (PG)/water was investigated. The effects of the surfactant mixture on the phase behavior and the concentration of water or oil in the systems were studied at three temperatures (50, 55, 60 °C) and with varied NaCl solutions (0.5; 2; 11%). Electrical conductivity measurement, FTIR spectroscopy and the DSC method were applied to determine the structure and type of the microemulsions formed. The dimension of the microemulsion droplets was characterized by dynamic light scattering. It has been stated that the concentration of CEO20 has a strong influence on the shape and extent of the microemulsion areas. Addition of a nonionic surfactant to the mixture with MAG promotes an increase in the area of microemulsion formation in the phase diagrams, and these areas of isotropic region did not change considerably depending on the temperature, NaCl solution and oil type. It was found that, depending on the concentration of the surfactant mixture, it was possible to obtain U-type microemulsions with dispersed particles size distribution ranging from 25 to 50 nm and consisting of about 30–32% of the water phase in the systems. The conditions under which the microemulsion region was found (electrolyte and temperature—insensitive, comparatively low oil and surfactant concentration) could be highly useful in detergency

Microfluidic analysis techniques for safety assessment of pharmaceutical nano- and microsystems

This chapter reviews the evolution of microfabrication methods and materials, applicable to manufacturing of micro total analysis systems (or lab‐on‐a‐chip), from a general perspective. It discusses the possibilities and limitations associated with microfluidic cell culturing, or so called organ‐on‐a‐chip technology, together with selected examples of their exploitation to characterization of pharmaceutical nano‐ and microsystems. Materials selection plays a pivotal role in terms of ensuring the cell adhesion and viability as well as defining the prevailing culture conditions inside the microfluidic channels. The chapter focuses on the hepatic safety assessment of nanoparticles and gives an overview of the development of microfluidic immobilized enzyme reactors that could facilitate examination of the hepatic effects of nanomedicines under physiologically relevant conditions. It also provides an overview of the future prospects regarding system‐level integration possibilities facilitated by microfabrication of miniaturized separation and sample preparation systems as integral parts of microfluidic in vitro models.Non peer reviewe

Pharmaceutical nonionic oil-in-water microemulsions

SIGLEAvailable from British Library Document Supply Centre-DSC:DXN026525 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Light-scattering investigations on dilute nonionic oil-in-water microemulsions

Dilute 3-component nonionic oil-in-water microemulsions formulated with either a polyoxyethylene surfactant (C18∶1E10 or C12E10) or the alkylamine-N-oxide surfactant, DDAO (C12AO), and containing either a triglyceride or an ethyl ester oil have been examined using dynamic and static light-scattering techniques. Analysis of the results showed distinct differences in the tested oils mode of incorporation into the microemulsion droplets, with both the molecular volume of the oil and the hydrophobic chain length of the surfactant being important. For example, microemulsions formulated by C18∶1E10 and containing one of the larger molecular volume oils (that is, either a triglyceride, Miglyol 812, or soybean oil) or the ethyl ester of fatty acid oil, ethyl oleate, exhibited first a decrease and then an increase in hydrodynamic size and surfactant aggregation number, suggesting that the asymmetric C18∶1E10 micelles became spherical upon the addition of a small amount of oil and grew thereafter because of further oil being incorporated into the core of the spherical microemulsion droplet. A similar conclusion of sphericity could not be drawn for microemulsions stabilized by C18∶1E10 and containing one of the oils smaller in molecular volume (namely tributyrin, ethyl butyrate, or ethyl caprylate) where neither the aggregation number nor the hydrodynamic radius changed much upon the addition of oil. This result suggested that these oils were preferentially located in the interfacial surfactant monolayer, behaving in much the same way as a cosurfactant. A different trend of results, however, was seen for microemulsions prepared using C12E10 and C12AO, most likely because these surfactants produced approximately spherical micelles. In this case, the microemulsions containing the oils larger in molecular volume tended to exhibit an increase in surfactant aggregation number and hydrodynamic size, suggesting the growth of spherical micelles, while the smaller oils (in particular ethyl butyrate) caused a significant decrease in surfactant aggregation number incompatible with their being incorporated into the centre of the droplet, suggesting that the oils were being located in the interfacial surfactant monolayer. These results suggest that the various oils are incorporated into the microemulsions in very different ways