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The commercially available Polysorbate 80 (PS-80) is a highly heterogeneous product. It is a complex and structurally diverse mixture consisting of polymeric species containing polyoxyethylenes (POEs), fatty acid esters, with/or without a carbohydrate core. The core is primarily sorbitan, with some isosorbide and sorbitol. Depending on the sources of fatty acids and the degrees of esterification, multiple combinations of fatty acid esters are commonly observed. A number of POE intermediates, such as polyoxyethylene glycols, POE-sorbitans, POE-isosorbides, and an array of fatty acid esters from these intermediates remain in the raw material as well. The complex composition of PS-80 is difficult to control and poses a significant characterization challenge for its use in the pharmaceutical industry. Here, we present a novel solution for PS-80 characterization using ultra high-performance liquid chromatography coupled with charge-reduction high resolution mass spectrometry. Post column co-infusion of triethylamine focused the signal into mainly singly charged molecular ions and reduced the extent of in-source fragmentation, resulting in a simpler ion map and enhanced measurement of PS-80 species. The data processing workflow is designed to programmatically identify PS-80 component classes and reduce the burden of manually analyzing complex MS data. The 2-dimensional graphical representation of the data helps visualize these features. Together, these innovative methodologies enabled us to analyze components in PS-80 with unprecedented detail and shall be a useful tool to study formulation and stability of pharmaceutical preparations. The power of this approach was demonstrated by comparing the composition of PS-80 obtained from different vendors.

This study aimed to develop a niosome-encapsulated clindamycin phosphate (CMP) formulation for topical delivery. The possibility of encapsulation of this antibiotic in niosomes, its stability, cytotoxicity, and antibacterial capability were evaluated. Diverse combinations of sorbitan esters and their ethoxylated derivatives with cholesterol were used to prepare the lipid vesicles. This series of niosomes had high physical stability depicted as unchanged size distribution curves during 6-month storage. Formulations composed of Span 60 and Tween 60 in combination with 30 mol% of cholesterol exhibited the highest encapsulation efficiency (47.14%). Minimal inhibitory concentration of the niosomal CMP against Staphylococcus aureus was higher than free CMP. Slow and biphasic release profile of CMP was also shown. These results indicate that niosomes can be used as stable carriers for topical delivery of CMP in acne.

A new effective biocatalyst was prepared by coating lipase from Candida cylindracea with sorbitan esters such as span 60 and 65. This biocatalyst was characterized by employing the Scanning Electron Microscopy, X-Ray diffraction patterns and a lipase assay. The type of surfactant used during the lipase modification process has shown significant effect in the lipase activity and the protein content of the modified lipase complex. It was found that catalytic behavior of modified lipase was greatly affected by the source of the used span. Span 65-coated Candida cylindracea lipase showed the highest conversion of 50% in enzymatic esterification of glucose and lauric acid.

In this work, we prepared nonionic surfactants from waste cooking oil materials. Hydrolysis was carried out for palm and palm kernel waste cooking oils to get a mixture of free fatty acids. The mixture of free acids was esterified with sorbitan and then ethoxylated at different ethylene oxide units. Two surfactants exhibited promising surface-active properties among the six prepared surfactants based on the results of surface tension. The interfacial tension (IFT) around the critical micelle concentration was measured against a series of n-hydrocarbon to detect the minimum alkane carbon number (ACN) (Πmin) for each of these surfactants. The effect of normal and branched alcohols on Πmin was also studied to design the surfactant/alcohol mixture for the chemical flooding process. From the results of IFT, the ethoxylated ester derivatives of palm kernel fatty acids (EPK-20) exhibited minimum IFT γmin (0.06 mN m–1) at Πmin equal to 12, and the ethoxylated ester derivatives of palm fatty acids (EP-40) achieved γmin equal to 0.09 mN m–1 at Πmin of 10. Branched alcohols shifted Πmin to a higher value to reach the equivalent ACN of the crude oil and decrease the IFT to lower values. The flooding process showed that the maximum oil recovery was obtained by EPK-20 (54.2% when used purely and 66.2% when used with isoamyl alcohol). In comparison, EP-40 exhibited that oil recovery equals 46% without alcohol and 46.4% with iso-butanol alcohol. The results were interpreted and discussed based on interfacial properties, wettability alteration, and the ACN.

Surface active agents have been used in many pharmaceutical formulations for different purposes as penetration enhancers. In this study, the penetration enhancement activity of four nonionic surfactants from polyoxyethylene sorbitan fatty acid esters alone and in combination with some short-chain alcohols on red blood cells were investigated. Hemolysis at different concentrations of each nonionic surfactant (0.1, 0.2, 0.5, 1, and 2%) and ethanol, isopropyl alcohol, glycerol, and propylene glycol (0.5, 1, 2, 5, and 10% w/v) were investigated. Critical micelle concentration (CMC) and micellization thermodynamic parameters of tween 80 in presence of ethanol and glycerol at different concentrations were determined. The influence of the ethanol and glycerol on nonionic surfactant micelle formation was evaluated by determining CMC and micellization thermodynamic parameters of tween80 at different concentrations of alcohol-tween mixtures. The mixture of Tween 20 and glycerol have the lowest hemolytic activity while tween 80-ethanol mixture has the highest hemolysis activity. The self-aggregation of surfactant monomers was affected by short-chain alcohols. The structure breaking ability of alcohol and their interactions with the hydrophilic-hydrophobic groups of surfactants might be the main factors for changing the micelle formation. The CMCs of tween 80 was incremented by increasing the concentration of alcohol. The results indicated that by adding and increasing short chain alcohols the CMCs increased also the CMCs were increasing through raising the temperature (while in the presents of surfactants alone the CMCs decreased by raising temperature).

Nonionic surfactant interfaces are often considered to be unaffected by aqueous ions. However, ions often localize to interfaces and, as such, can interact with surfactants either via direct contact or by affecting interfacial hydrogen bond structures in water. Characterizing these effects is essential to understanding how ions affect interfacial properties at the oil-water interface in the presence of nonionic surfactants. Here, we use two-dimensional infrared (2D IR) spectroscopy in combination with atomistic molecular dynamics (MD) simulations to study the effects of high-concentration Na+ and Ca2+ ions on interfacial hydrogen bond dynamics in heterogeneous sorbitan stearate reverse micelles. Experiments show only minor changes in interfacial hydrogen bond populations when salts are added but those interfacial water network dynamics are slowed by nearly 300%. Molecular dynamics simulations show the slowdown results from an increased disorder in surfactant headgroup orientation and packing density, which stabilizes hydrogen bonding interactions between surfactants and interfacial water.

Since traditional nonyl phenyl type nonionic surfactants have been known as destructive to the ecosystem, sorbitan nonionic surfactants (Tween 20, 40, 60 and 80) were used to make acrylic emulsion ...

Hydrolysis of polysorbate in biopharmaceutical liquid formulations upon long-term storage represents a risk factor, since reduction of the intact surfactant concentration may compromise protein stability. Moreover, accumulation of polysorbate degradation products is associated with the formation of particulates potentially affecting drug product stability and quality. These effects are conventionally assessed by real-time end-of-shelf life studies constituting an integral yet lengthy process of formulation development. To accelerate this procedure, we describe here a powerful tool to conduct shake stress studies based on the controlled hydrolysis of polysorbate 20 by beads-immobilized lipases. For this purpose, the production of stable, partially degraded material characterized by a representative presence of non-emulsifying degradants such as ethoxylated sorbitan and free fatty acids was monitored by state-of-the-art chromatographic methods ensuring realistic pharmaceutical conditions. Freeze-thaw, shaking and shipping stress studies of a mAb formulation did not only demonstrate that this approach is useful to determine the critical degradation level impairing drug product quality, but furthermore revealed significant differences in protective effects depending on the hydrolysis pattern. As these results emphasize, the outlined strategy may support formulation scientists to unveil the interrelationship between polysorbate hydrolysis products and stabilization of the active pharmaceutical ingredient in a holistic and time-saving manner.

We are reporting on the interaction of zinc oxide (ZnO) nanoparticles (NPs) with the lyotropic phase comprises of Polyoxyethylene (20) sorbitan monolaurate and protic solvent ethylene glycol. The c...

The objective of this study is to investigate the effects of three different organogelators, sorbitan monostearate (SMS), soya lecithin (SL) and glyceryl monostearate (GMS) prepared at different concentrations (12%, 15% and 18%, w/w) on the structural, thermal and mechanical properties of palm olein (PO)-based organogels. Polarized light microscopy analysis revealed needle-like crystals in SMS-PO, rod-shaped tubules in SL-PO and rosette-like aggregates in GMS-PO organogels. Intermolecular hydrogen bonding and van der Waals forces were the main drivers for the self-aggregation of these organogelators in PO, as observed in Fourier transform infrared (FTIR) spectroscopy. X-ray diffraction (XRD) results indicated β’-type polymorphic structure in SL-PO and GMS-PO. As the concentration of organogelators increased, there was a corresponding increase in the firmness, gel-sol transition (Tgs) and melting temperatures of the organogels. SMS-PO with amorphous structure had the lowest firmness, thus produced weaker gel with lower thermal stability. The oil binding capacity (OBC) of both SL-PO and GMS-PO were over 90%, significantly higher than that of SMS-PO organogels. These findings indicate that crystallization is the key determinant factor to the final properties of the organogel networks. This is influenced by the molecular structure and the concentration of the organogelators used.

Polysorbates (PS), commonly known as Tween (TM), are some of the most extensively used excipients and protein stabilisers in biopharmaceutical products worldwide. It is stipulated in the pharmacopoeia specifications that these ethoxylated surfactants are complex mixtures comprised of a wealth of molecular species. While little is known about the propensity of PSs to crystallise, they are used in applications ranging from food products, cosmetics, different types of drug dosage forms like creams and oral products to parenteral applications. However, in recent years a range of issues and safety concerns have appeared when using them for stabilising biopharmaceutical products including precipitation, particle formation, and adverse biological effects. Therefore, the aim of this study was to thoroughly characterise the thermotropic behaviour and mechanism of crystallisation of polysorbates with different hydrocarbon tails and their non-ethoxylated sorbitan ester equivalents for comparison. A systematic and comprehensive product characterisation was carried out, taking advantage of a combination of complementary techniques such as differential scanning calorimetry, matrix assisted laser desorption ionisation time-of-flight and small- and wide-angle X-ray diffraction. We show that polysorbate 80, having an unsaturated hydrocarbon tail, crystallises by the ethylene oxide chains in the headgroup. Polysorbate 20, 40, and 60, containing saturated hydrocarbon esters tails, crystallise not only by the ethylene oxide chains but also by their hydrocarbon tails. An analogous behaviour was observed for the PS non-ethoxylated equivalents, the sorbitan esters. Sorbitan esters with saturated hydrocarbon tails displayed a crystallisation of the tail upon cooling, whereas the sorbitan ester with unsaturated hydrocarbon tail displayed no crystallisation.

Polysorbates are widely used in food and cosmetic products and pharmaceuticals for emulsion stabilization, preventing surface absorption and as stabilizers against protein aggregation. But their impacts on the secondary structure and conformational stabilization of bovine casein, a typical intrinsically disordered protein (IDP), have not been fully addressed so far, which is crucial to evaluate the performance of polysorbates as stabilizer for food products containing bovine casein. Here, we assessed the effects of polysorbate 20 (PS-20) and polysorbate 80 (PS-80) on the secondary structure and conformation of bovine casein micelles by fluorescence and circular dichroism spectra, dynamic light scattering (DLS), small angle x-ray scattering (SAXS) and transition electron microscopy (TEM). In addition, three-dimensional structure of bovine β-casein, a major component of bovine casein, was predicted using homology modelling with the aid of PSIPRED server to outline the potential binding sites of bovine casein for polysorbates. We found that PS-20 presented a higher binding affinity (Ka = 3.76 × 106 M−1) and stoichiometry (n = 0.89) to bovine casein than that of PS-80 (Ka = 1.45 × 106 M−1, n = 0.45). The α-helical and β-sheet conformation of bovine casein was increased upon binding with PS-20 whereas binding of PS-80 had little impact on secondary structural elements of this milk protein. Moreover, bovine casein micelles were dissociated by PS-20, which co-assembled into micellar-like particles with a rather spherical shape and homogenous size distribution ranging from 20 to 50 nm in diameter. The lauric acid chains may bind with disordered regions connected by colloidal calcium phosphate (CCP) as the core, and the sorbitan groups may associate with N-terminal outwards as the shell providing hydrophilicity to stabilize the polysorbates-casein complex. On the contrary, PS-80 led to formation of sponge-like aggregates with the radius ranging from 200 to 500 nm as indicated by the data of DLS, SAXS and TME. We assume that the stearic hindrance originating from oleic group and the kink due to the cis-double bond in the sidechain of PS-80 contribute to the aggregation of bovine casein induced by PS-80. Furthermore, a tentative binding mechanism of polysorbates with bovine casein micelles and model of complexes were proposed to illustrate the polysorbates-induced structural change and conformational stabilization of bovine casein micelles. Thus, we argue that the difference in binding of polysorbates to bovine casein may influence the functional properties (emulsification, foaming ability, etc) of milk protein. Taken together, we suggest that PS-20 may be preferred option as potential protein stabilizer for dairy products, and careful consideration should be given when selecting PS-80 as stabilizer for bovine casein, a typical IDP.

Fatty alcohol-polysorbate 60-water ternary systems were used as models to represent the continuous phases of the respective semisolid oil-in-water emulsions for topical delivery of cosmetic and medicinal agents. The influence of batch variation of polysorbate 60 and fatty alcohol on structure and consistency of these systems was investigated using microscopy, rheology, differential scanning calorimetry and X-ray scattering techniques. The polysorbate 60 : cetostearyl alcohol mixed emulsifying wax showed swelling in water, that is, the lamellar repeat distance continually augmented from 93 to 125 Å with water percentage 20-90%. Cetostearyl alcohol ternary systems were thicker than cetyl alcohol ones independently of polysorbate 60 batches used. All the ternary systems showed an initial increase in consistency over the first 2 weeks of storage, which was followed by slight changes in consistency (cetostearyl alcohol systems) due to the re-allocation of polysorbate 60 molecules in the gel network or significant breakdown of structure (cetyl alcohol systems) due to the transformation of swollen α-lamellar gel phase into β, γ crystals on 25°C storage. With all fatty alcohols, the consistency of polysorbate 60 ternary system was directly dependent upon interlamellar water thickness as governed by the length and distribution of polyoxyethylene groups within polysorbate 60 molecules. In relation with the composition of polysorbate 60 batches used, the consistency of ternary systems was higher when prepared with the polysorbate 60 batch containing a greater amount of sorbitan polyoxyethylene monoesters. It was proposed that the swollen α-crystalline gel phase could be better formed by sorbitan polyoxyethylene monoesters rather than sorbitan polyoxyethylene diesters.Des systemes ternaires alcool gras-polysorbate 60-eau ont été utilisés comme modèles pour représenter les phases continues des émulsions huile-dans-eau semi-solides respectives pour l'administration topique d'agents cosmétiques et médicinaux. L'influence de la variation des lots de polysorbate 60 et d'alcool gras sur la structure et la consistance de ces systèmes a été étudiée en utilisant la microscopie, la rhéologie et la calorimétrie différentielle à balayage et la diffusion des rayons X. La cire émulsifiante mixte polysorbate 60 : alcool cétostearylique a montré un gonflement dans l'eau, c'est-à-dire que la distance de répétition du motif lamellaire a continuellement augmentée de 93 à 125 A° avec un pourcentage d'eau de 20-90%. Les systèmes ternaires d'alcool cétostearylique étaient plus épais que ceux d'alcool cétylique indépendamment des lots de polysorbate 60 utilisés. Tous les systèmes ternaires ont montré une augmentation initiale de la consistance au cours des 2 premières semaines de stockage, qui a été suivie par de légers changements de consistance (systèmes d'alcool cétostearylique) en raison de la re-affectation des molécules de polysorbate 60 dans le réseau de gel ou d’une rupture significative de structure (systèmes d'alcool cétylique) en raison de la transformation des phases lamellaires gonfles de type α-gel en cristaux β, γ conservés a 25°C. Avec tous les alcools gras, la consistance du système ternaire polysorbate 60 dépendait directement de l'épaisseur inter lamellaire de l'eau car gouverné par la longueur et la distribution des groupes de polyoxyethylène au sein des molécules de polysorbate 60. En relation avec la composition des lots de polysorbate 60 utilisés, la consistance des systèmes ternaires était plus élevée lorsque préparé avec le lot de polysorbate 60 contenant une plus grande quantité de monoesters de polyoxyethylene sorbitane. Il a été proposé que la phase de gel α-cristallin gonflé pourrait être mieux formée par des monoesters de polyoxyethylene sorbitane plutôt que des diesters de polyoxyethylene sorbitane.

Polysorbates (PSs) are synthetic nonionic surfactants consisting of polyethoxy sorbitan fatty acid esters. PSs have been widely employed as emulsifiers and stabilizers in various drug formulations and food additives. Recently, various PS-based formulations have been developed for safe and efficient drug delivery. This review introduces the general features of PSs and PS-based drug carriers, summarizes recent progress in the development of PS-based drug formulations, and discusses the physicochemical properties, biological safety, P-glycoprotein inhibitory properties, and therapeutic applications of PS-based drug formulations. Additionally, recent advances in brain-targeted drug delivery using PS-based drug formulations have been highlighted. This review will help researchers understand the potential of PSs as effective drug formulation agents.

In this experimental study, experiments were carried out using a nano-lubricant consisting of polyol ester (POE)-titanium dioxide (TiO2)-surfactant instead of POE oil used in the compressor in a refrigeration system cycle test apparatus. The main aim of the study was to provide more efficient operation of the refrigeration system. Triton X100 (TX-100) and sorbitan polyoxyethylene monooleate (Tween 80) were used as the surface-active material. Nano-lubricants were formed by mixing TiO2 nanoparticles with POE oil at different concentrations. At these different nanoparticle concentrations, 0.5% of the surfactant was used. The reason for using a surfactant in the nano-lubricant was to prevent agglomeration in the mixture. TX-100 and Tween 80 surfactants were also used to study the effects of the surfactant on the nano-lubricant. Experiments were carried out using three different concentrations and three measurements for each concentration using the POE/TiO2/surfactant nano-lubricants. The best improvement was achieved when a nano-lubricant consisting of a mixture of TX-100 and POE oil with a concentration of 1.5% TiO2 was used. The improvement in coefficient of performance (COP) for the refrigeration cycle was 39.42%. \

RATIONALE Approximately 7 million liters of Corexit® dispersants were applied during the 2010 Deepwater Horizon oil spill to facilitate the dispersion of crude oil. At the time of application, the exact chemical composition of Corexit® was relatively unknown. Characterization of Corexit® 9500 was performed using high-resolution mass spectrometry to further understand the complexity of the nonionic surfactant components of this mixture. METHODS Corexit®9500 was analyzed by ultra-high-performance liquid chromatography (UHPLC) coupled to a high resolution Orbitrap Fusion Lumos mass spectrometer operated in positive electrospray ionization mode and a charged aerosol detector. Chromatographic conditions were optimized to efficiently separate isobaric and isomeric compounds. Polyethoxylated nonionic surfactants in Corexit® 9500 were identified using the following criteria: accurate mass (

In this study, we sought to develop methods for amphiphilic engineering of bioresorbable polymers, sorbitan–poly(lactic acid) (sorbitan–PLA) and poly(ethylene glycol)–polylactic acid (PEG–PLA), by melt polycondensation of lactic acid in the presence of the binary initiators sorbitan and methoxy PEG in a single reactor. Briefly, oligo(lactic acid) (OLA) was first prepared by distilling water out of lactic acid under vacuum; then, sorbitan and methoxy PEG were introduced in the reactor, followed by the simultaneous polycondensation of OLA onto sorbitan and methoxy PEG, resulting in a mixture containing sorbitan–PLA/PEG–PLA copolymers. Without further purification, the recovered products were dissolved in saline buffer, mixed with squalane oil, and then homogenized to construct a stable colloidal vesicle. Then, we conducted a mechanistic study to progressively elucidate the relationship between the dispersion structure and the sustained release of a model protein bovine serum albumin. This one-pot approach has potential for applications and commercial use in the field of biodegradable controlled-release delivery systems. This study describes the production of the amphiphilic bioresorbable polymers sorbitan–PLA and PEG–PLA in a single reactor. This method aims to simplify the separation process and reduce purification costs while increasing the chemical yield. The obtained mixtures could stabilize squalene/water interfaces, resulting in a double-dispersion structure that is favorable for encapsulation in sustained delivery applications.

Characterizing the hydrogen bond structure and dynamics at surfactant interfaces is essential for understanding how microscopic interactions translate to bulk microemulsion properties. Heterogeneous blends containing tens or hundreds of surfactants are common in the industry, but the most fundamental studies have been carried out on micelles composed of a single surfactant species. Therefore, the effect of surfactant heterogeneity on the interfacial structure and dynamics remains poorly understood. Here, we use ultrafast two-dimensional infrared spectroscopy and molecular dynamics simulations to characterize sub-picosecond solvation dynamics as a function of the surfactant composition in ∼120 nm water-in-oil reverse micelles. We probe the ester carbonyl vibrations of nonionic sorbitan surfactants, which are located precisely at the interface between the polar and nonpolar regions, and as such, report on the interfacial water dynamics. We show a 7% increase in hydrogen bond populations together with a 37% slowdown of interfacial hydrogen bond dynamics in heterogeneous mixtures containing hundreds of species, compared to more uniform compositions. Simulations, which are in semiquantitative agreement with experiments, indicate that structural diversity leads to decreased packing efficiency, which in turn drives water further into the otherwise hydrophobic region. Interestingly, this increase in hydration is accompanied by a slowdown of dynamics, indicating that water molecules solvating surfactants are conformationally constrained. These studies demonstrate that the composition and heterogeneity are key factors in determining interfacial properties.

Present article discusses the formation of a bigel formulation for drug delivery applications via a newly developed green approach using gamma radiation induced crosslinking. Bigels were prepared using olive oil/sorbitan-monopalmitate/sterculia gum and are designated as green alternative renewable materials. The polymer samples were characterized by cryo-SEMs, FTIR, 13C NMR, TGA, DTG, DSC, microscopic analysis and swelling studies. The release profile of a drug moxifloxacin was determined along with the evaluation of various biomedical properties, including biocompatibility and mucoadhesion, as well as antioxidant and mechanical properties. The release profile of drug moxifloxacin from olive oil–SMP–sterculia-cl-poly(acrylamide) (AAm) bigels followed non-Fickian diffusion mechanism. The release profile of the drug from drug loaded olive oil–SMP–sterculia-cl-poly(AAm) bigels was best fitted by Higuchi kinetic model. The results indicated that sterile and pure bigel formulations could be used as gastrointestinal drug delivery systems owing to their haemocompatible, non-haemolytic, mucoadhesive, antioxidant and viscoelastic nature.

The confinement of Bronsted acidic 1-methyl-3-(3-sulfopropyl)-1H-imidazol-3-ium hydrosulfate ([PSMIm][HSO4]) into the channel walls of two-dimensional (2D) COFs using a one-pot self-assembly strategy was achieved by incorporating an imine-linked TPB–DMTP–COF (TPB, triphenylbenzene; DMTP, dimethoxyterephthaldehyde) as the host. An appropriate loading of [PSMIm][HSO4] is crucial for the BIL–COF hybrids to maintain proper geometry in the channel and sufficient acidic sites for the sorbitol substrate and sorbitan intermediate to enter and react. The best yield of isosorbide (97%) from sorbitol to date was obtained in the presence of BIL–COF-30 as the catalyst under optimized conditions. Besides, BIL–COF-30 can be recycled for at least five runs without activity loss.

The discoloration of chlorophyll (Chl) by light is an ongoing issue for green beverages in the food industry. To suppress the discoloration of Chl in aqueous solution, the effects of different emulsifiers were investigated on the discoloration of Chl under ultraviolet (UV) irradiation to determine their potential application for use as food additives. Sucrose fatty acid ester (SE), sorbitan fatty acid ester (TW), and quillaja saponin (QS) were used as emulsifiers, while Triton X-100 (TX) was used for reference. The discoloration of Chl was measured using a color difference meter. The species of Chl in solution were determined using ultraviolet-visible (UV-Vis), fluorescence, and circular dichroism (CD) spectroscopy, and the particle size of Chl in solution was determined using dynamic light scattering. The Chl aggregates were observed by the observation of increased peak areas at longer wavelengths in the UV spectra of Chl, in addition to a reduced fluorescence intensity. The CD spectra showed that the Chl aggregates were arranged in a random structure. Furthermore, the average particle size of the Chl aggregates was determined to be approximately 100 nm. SE and QS were found to significantly enhance the formation of self-aggregates due to their high hydrophilicities compared to those of TW and TX. As a result, SE and QS protect themselves from light to suppress the discoloration of Chl. The present results therefore suggest that SE and QS are suitable emulsifiers to address the problem of Chl discoloration in beverages, such as green tea and vegetable juices. PRACTICAL APPLICATION: Chlorophyll (Chl), a green pigment present in vegetables and green tea, is discolored by light. In this study, it was found that emulsifiers (sucrose fatty acid ester and quillaja saponin) suppress the discoloration of Chl. The implementation of these emulsifiers as food additives would enable green tea or green vegetable juices to maintain their colors for long periods and could contribute significantly to the beverage industry.

The effect of adding ethoxylated sorbitan ester surfactants (Tweens®) to poly(ethylene glycol) diacrylate-based monolithic recipes was investigated. Five different Tweens® have been evaluated to investigate the exact role of non-ionic surfactants in poly(ethylene glycol) diacrylate-based monolith preparations. These monoliths were characterized by scanning electron microscopy, infrared spectroscopy, and nitrogen physisorption analysis. Different morphological features, and surface areas were observed when different types of Tween® were included in the recipe; Tween® 20 and 85 showed small globules, while Tween® 40, 60 and 80 exhibited larger globular structures with different sizes and degrees of coalescence. The different Tween®-based monoliths were investigated for the chromatographic separation of mixtures consisting of hydroxybenzoic acids and alkylbenzenes. These columns were mechanically stable, except for Tween® 80. The highest methylene selectivity and the best overall performance were achieved by Tween® 60. The efficiency was increased by increasing the concentration of the Tween® 60 and the amount of poly(ethylene glycol) diacrylate Mn 700 in the recipes up to 30 wt%, each. Further increases in either Tween® 60 or poly(ethylene glycol) diacrylate Mn 700 led to formation of non-permeable columns. The optimized column was successfully used for separation of mixtures of nonsteroidal anti-inflammatory and sulfa drugs, with a maximum efficiency of 60,000 plates/m. Refereed/Peer-reviewed

As a result of the synthesis protocol polyoxyethylene sorbitan monooleate (polysorbate 80, PS80) is a highly complex mixture of compounds. PS80 was therefore separated into its main constituents, e.g. polyoxyethylene isosorbide esters and polyoxyethylene esters, as well as mono- di- and polyesters using preparative high-performance liquid chromatography. In this comprehensive study the individual components and their ethoxylation level were verified by matrix assisted laser desorption/ionization time-of-flight and their thermotropic behavior was analyzed using differential scanning calorimetry and X-ray diffraction. A distinct correlation was found between the average length of the ethylene oxide (EO) chains in the headgroup and the individual compounds’ ability to crystallize. Importantly, a critical number of EO units required for crystallization of the headgroup was determined (6 EO units per chain or 24 per molecule). The investigation also revealed that the hydrocarbon tails only crystallize for polyoxyethylene sorbitan esters if saturated. PS80 is synthesized by reacting with approximately 20 mol of EO per mole of sorbitol, however, the number of EO units in the sorbitan ester in commercial PS80 products is higher than the expected 20 (5 EO units per chain). The complex behavior of all tested compounds revealed that if the amount of several of the linear by-products is reduced, the number of EO units in the chains will stay below the critical number and the product will not be able to crystallize by the EO chains.

This paper addresses sorbitan and sucrose ester in physical transformations of palm mid-fraction (PMF). Both emulsifiers influenced the crystallization properties of PMF, mainly due to emulsifier solubility, which affects its ability to interfere with the kinetics of solution-mediated phase transformations. DSC results corroborate the polymorphism analysis, indicating that the mechanism and rate of phase transformation depend on the chemical structure and amount of each emulsifier. The addition of sorbitan tristearate (STS) and sucrose stearate (S-370) increased the crystallization speed of the PMF and caused changes in the crystallization behavior. STS favored the β'→β transition, while S-370 stabilized the β'-form. We can conclude that the presence of emulsifiers dissimilar to the composition of PMF modified its physical structure, either by increasing the liquid fraction or by reducing molecular motion, facilitating or preventing polymorphic transformations.

International audience; We present a new membrane mimetic system using a membrane softening detergent commonly known as Tween 80 (TW80), to form oriented systems for solid-state NMR applications. TW80 is a fatty acid ester (oleate) of sorbitan polyethoxylate and a mild non-ionic surfactant. Phosphatidylcholine (PC)/TW80 model membrane systems were characterized by solid-state NMR and FTIR spectroscopy. 31 P and 2 H NMR spectra showed that DMPC (14:0) and DPPC (16:0) self-assemble with TW80 to form oriented structures, and maintain alignment over a wide range of molar ratios and temperatures. The addition of lanthanide ions revealed that the membrane alignment can be flipped from parallel to perpendicular with respect to the magnetic field direction. Using 15 N solid-state NMR and a labeled model transmembrane peptide, we showed that TW80-based membranes can be employed to determine the peptide orientation in the magnetic field, which is useful for structural determination. Altogether, our work showed that TW80 could be exploited for direct and efficient membrane protein extraction and to enhance membrane and membrane protein orientation without using a detergent removal step. This approach could be extended to a wide range of membranes including native ones.

Two of the most widely used surfactants to stabilize biologicals against e.g. interfacial stress are polysorbate 20 (PS20) and polysorbate 80 (PS80). In recent years, polysorbate degradation in biopharmaceutical formulations has been observed. Polysorbate (PS) is mainly composed of sorbitan and isosorbide fatty acid (FA) esters, varying in their FA composition. Especially hydrolysis, which can be induced chemically as well as enzymatically, leads to the release of FAs from PS. These FAs are poorly soluble in aqueous buffer systems due to their hydrophobic nature and therefore prone to precipitation and particle formation. Since the emergence of particles in liquid formulations has to be avoided, it is important to prevent their formation. This study evaluates the solubility limits of selected FAs, which are likely to be released during the degradation of PS20 and PS80 in the presence of defined PS concentrations. Our results show that the solubility is highly dependent on the pH, the temperature, the used PS concentration and the aliphatic chain of respective FAs. Solubility of FAs, such as palmitic and oleic acid under the conditions determined in this study, are in the range of 3–130 µg·ml−1 (12–460 µM). Furthermore, the results allow making an estimation to which extent PS may degrade before particle formation in the drug product may be expected.

The transdermal delivery of sparingly soluble drugs is challenging due to of the need for a drug carrier. In the past few decades, ionic liquid (IL)-in-oil microemulsions (IL/O MEs) have been developed as potential carriers. By focusing on biocompatibility, we report on an IL/O ME that is designed to enhance the solubility and transdermal delivery of the sparingly soluble drug, acyclovir. The prepared MEs were composed of a hydrophilic IL (choline formate, choline lactate, or choline propionate) as the non-aqueous polar phase and a surface-active IL (choline oleate) as the surfactant in combination with sorbitan laurate in a continuous oil phase. The selected ILs were all biologically active ions. Optimized pseudo ternary phase diagrams indicated the MEs formed thermodynamically stable, spherically shaped, and nano-sized (&lt, 100 nm) droplets. An in vitro drug permeation study, using pig skin, showed the significantly enhanced permeation of acyclovir using the ME. A Fourier transform infrared spectroscopy study showed a reduction of the skin barrier function with the ME. Finally, a skin irritation study showed a high cell survival rate (&gt, 90%) with the ME compared with Dulbecco&rsquo, s phosphate-buffered saline, indicates the biocompatibility of the ME. Therefore, we conclude that IL/O ME may be a promising nano-carrier for the transdermal delivery of sparingly soluble drugs.

Although the cytotoxic and permeation enhancing activities of some fatty acid esters (FAEs) have been studied individually, there lacks systemic studies on how their molecular structures can affect these activities and how the activities would change when FAEs form micelles or nanoemulsion droplets. Therefore, this study aims to address these issues by investigating the cytotoxic and permeation enhancing effects of twenty-six FAEs in lipid droplets on Madin-Darby Canine Kidney (MDCK) cell monolayer. The effect of FAEs on the cytotoxicity and the transport of nanoemulsion droplets depends on how easy the FAE monomers can diffuse out of the droplets and perturbate into the cellular membrane, which determined by the critical structures of FAEs including hydrophilic head size, chain length, number of chains, and number of double bond(s) in the chain. The less the intermolecular attraction, the easier the monomer to diffuse out of the lipid droplets and the more interaction with the cell monolayer. Fatty acid monoester (FAME) with less intermolecular attraction than di- and tri-esters had more cytotoxic and higher permeation enhancing effects. Among the FAMEs, the cytotoxicity and permeation enhancing effects were in the order: medium-chain with small hydrophilic head (propylene glycol and glycol) > long-chain with two double bonds > medium-chain with large head (sorbitan, polyethylene glycol, sucrose, and PEGylated sorbitan) ≈ long-chain with single double bond > saturated long-chain, which are consistent with the intermolecular attraction force (low-high). However, the more kinks in the monomer’s tail caused by the double bond, the less the monomer can perturbate into the cell membrane, resulting in less cytotoxicity and permeation enhancement. In conclusion, the FAEs with less intermolecular attraction and straight chain have more cytotoxic and permeation enhancing effects when formulated in nanoemulsion.

Vesicles are described and evaluated in this chapter. Liposomes are lipid bilayers rolled up into spherical shells with enclosed liquid within shells, separated from the outer (surrounding) liquid solution. On the other hand, elastic liposomes (ELs; Transfersomes) are phospholipid vesicles similar to traditional liposomes, but they are different from the latter because of the presence of edge activators (surfactants) that impart deformability and elasticity. It has been reported that these vesicles can enter the bloodstream through the skin. The claim that ELs can permeate intact skin is still controversial since skin pores can be opened without major impairment to only 20–40 nm. It has been postulated that Transfersomes are transported across the skin via concentration-independent, naturally occurring, and most likely hydration-based, transepidermal gradient(s). The chapter also discusses other vesicles such as other surfactant-based elastic vesicles, niosomes, ethosomes (ESMs), and transethosomes. The elastic vesicles were formulated from the micelle-forming surfactant octaoxyethylene laurate ester (PEG-8-L) and the bilayer-forming surfactant sucrose laurate ester (L-595). When nonionic surface active agents self-assemble, they form vesicles called niosomes. Nonionic surfactants such as polysorbates (Tweens), polyethoxy fatty ethers (Brij), and sorbitan fatty acid esters (Spans) are used for the preparation of niosomes. Compared to liposomes, niosomes have a larger membrane flexibility, a higher chemical stability, and a low cost of production. ESMs refer to lipid vesicles with relatively high ethanol content. These vesicular systems can increase the skin permeation of medications. Most ESMs are prepared from phospholipid, water, and ethanol. ESMs may also contain propylene glycol or isopropyl alcohol along with ethanol. Transethosomes are vesicles formulated by adding penetration enhancers or an edge activator (surfactant) to conventional ESMs. Transethosomes combine the advantages of ESMs and deformable liposomes.

Developing a facile method to prepare edible oleogels under moderate conditions would be of great interest. In this research, oleogels were obtained directly from the mixtures of cellulose particles (average particle size ≈ 25μm), sorbitan fatty acid esters (Span60 and Span40) and medium chain triglycerides (MCT). Results showed that 6% (w/w) cellulose particles combined with 9% (w/w) sorbitan fatty acid esters could form a strong network to trap the oil phase through ultra-sonic treating. The strength of the oleogels could be regulated by the cellulose particles content and its ratio to surfactant. XRD, DSC and SEM data revealed that there was synergetic effect between the cellulose particles and fatty acid esters during the gelation. The cellulose particles covered with Span60 could associate with each other to form a network in the oil phase, in the similar way to the Span60 micelles. These findings would be significant for the development and application of food grade oleogels.

Advantages associated with the use of polylactic acid (PLA) nano- or microparticles as drug delivery systems have been widely proven in the field of pharmaceutical sciences. These biodegradable and biocompatible carriers have demonstrated different loading and release properties depending on interactions with the cargo, preparation methods, particles size or molecular weight of PLA. In this study, we sought to show the possibility of influencing these properties by modifying the structure of the constituting polymer. Seven non-functionalized or functionalized PLA polymers were specifically designed and synthesized by microwave-assisted ring-opening polymerization of d,l-lactide. They presented short hydrophobic and/or hydrophilic groups thanks to the use of C20 aliphatic chain, mPEG1000, sorbitan esters (Spans®) or polysorbates (Tweens®), their PEGylated analogues, as initiators. Then, seven types of drug-loaded nanoparticles (NP) were prepared from these polymers and compared in terms of physico-chemical characteristics, drug loading and release profiles. Although the loading properties were not improved with any of the functionalized PLA NP, different release profiles were observed in an aqueous medium at 37 °C and over a period of five days. The presence of PEG moieties in the core of PLA-polysorbates NP induced a faster release while the addition of a single aliphatic chain induced a slower release due to better interactions with the active molecule.

Mg(OH)2 was considered as an environment-friendly material that has been received extensive attention on environmental remediation. It has low aqueous solubility that could slowly dissolve and provide a long-term source for alkalinity. However, the poor suspension stability and positive surface charge restrict its utilization in groundwater remediation. In this study, stable, negatively charged and cost effective colloidal Mg(OH)2 was synthesized. Fourier infrared spectrum, surface charge and microscope photographs of colloidal Mg(OH)2 were measured to analyze the modified mechanism of surfactant to Mg(OH)2. Column tests were conducted to investigate the transport and slow OH− releasing properties of colloidal Mg(OH)2. Experimental results indicated that sodium dodecyl sulfate (SDS) could significantly enhance the stability of Mg(OH)2 suspension while needed large consumption (over its critical micellar concentrations(CMC)). Polyoxyethylene sorbitan fatty acid ester (Tween-80) could significantly decrease the CMC of SDS, leading to more aggregation of SDS around Mg(OH)2 particle surface, increasing the utilization of SDS, and formulating relatively stabled double layer structure. Colloidal Mg(OH)2 could both be intercepted by porous media and have certain mobility in aquifer, exhibiting a long pH buffering capacity after it was injected to aquifer.

Penicillium frequentans can be used in the management of brown rot caused by Monilinia spp. Competition is the primary mode of biocontrol activity of P. frequentans, which must therefore cover most of fruit surface to avoid pathogen infection. Our objective was to optimize the efficacy of P. frequentans by maximizing fruit surface coverage and retention with the antagonist formulation by surfactant incorporation.; Results: Sixteen surfactants were assessed for the management of brown rot at 3-5 different concentrations. Nine surfactants increased the droplet surface up to 2.5 times compared with water on an inert surface, with or without the presence of P. frequentans in each drop. Eight surfactants increased P. frequentans on the fruit surface, enhancing colony forming units after run off or lateral spray application uptake by 50% compared to the control without surfactants. But only some doses of sodium carboxymethyl cellulose, gelatin, Tween 20, sorbitan alkyl esters, synthetic latex, polyethylene glycol isotridecyl ether, and hydroxypropyl methylcellulose could show the same covered fruit surface after run off or lateral spray application. There were also no phytotoxic side-effects on five different species of stone fruit.; Conclusions: The efficacy of P. frequentans dry conidia can be enhanced by optimizing the composition of the formulation with surfactants. © 2018 Society of Chemical Industry.; © 2018 Society of Chemical Industry.

The potential of proniosomes as a transdermal drug delivery system for Atenolol was investigated by encapsulating the drug in various formulations of proniosomal gel composed of various ratios of sorbitan fatty acid esters, cholesterol, lecithin prepared by Coacervation-phase separation method. The objectives of the present study were to define effects on the antihypertension activity and pharmacokinetics of a novel transdermal Proniosomal gel incorporating Atenolol. The formulated systems were characterized in vitro for size, drug entrapment, In vitro and in vivo drug permeation profiles and vesicular stability at different storage conditions. The optimized Atenolol proniosomes (AT8) showed nanometric vesicle size, high entrapment efficiency and marked enhancement in transdermal permeation. The prepared Proniosomal gel showed the relative bioavailability of 365.38 fold increased for AT8 than oral. The maximal concentrations (Cmax), of drug were significantly reduced while the areas under the plasma concentration–time curve (AUC), and mean residence times (MRT), t1/2 were evidently increased and extended, respectively. The results suggest that proniosomes can act as promising carrier which offers an alternative approach for transdermal delivery of Atenolol. Keywords: Proniosomes, Atenolol, Niosomes, Pharmacokinetic study, Transdermal delivery

We comprehensively studied the complexity of the mode of action of adjuvants by uncoupling the parameters contributing to the spray process during foliar application of agrochemicals. The ethoxylated sorbitan esters Tween 20 and Tween 80 improved the efficiency of pinoxaden (PXD) in controlling grass-weed species in greenhouse experiments by aiding retention, having humectant properties, maintaining the bioavailability, and increasing the cuticular penetration of PXD. The nonethoxylated sorbitan esters Span 20 and Span 80 showed minimal effects on retention, droplet hydration, or cuticular penetration, resulting in reduced PXD effects in the greenhouse. Tris(2-ethylhexyl)phosphate (TEHP) does not contribute much to retention and spreading but strongly enhances the diffusion of PXD across isolated P. laurocerasus cuticular membranes. As TEHP was most efficient in controlling the growth of grass-weed species, we propose that the direct effect of penetration aids on cuticular permeation plays a key role in the efficiency of foliar-applied agrochemicals.

Ionic Liquid (ILs) in oil microemulsions (IL/O MEs) have emerged as a potential carrier for transdermal drug delivery, particularly for sparingly soluble drug molecules, such as acyclovir and methotrexate. However, less attention was paid in the selection of non-toxic and biodegradable ILs. In this paper, we report new IL/O MEs with ammonium acetate ILs, which can dissolve acyclovir and methotrexate significantly. Microemulsions were composed of a mixture of nonionic surfactants, polyoxyethylene sorbitan monooleate (Tween-80), and sorbitan laurate (Span-20)/ILs/oil isopropyl myristate (IPM). Three ILs called 1-ethyl-3-methylimidazolium acetate ([EMIM][OAc]), triethylammonium acetate ([TEA][OAc]) and diethylammonium acetate ([DEA][OAc]) were selected due to their non-toxic property. Based on the pseudo-ternary diagrams constructed, it was evident that Span-20 played the key role as a surfactant while Tween-80 acted as the co-surfactant, showing optimal dissolution of the ILs into the system prepared with a ratio of 1:3 (Tween 80:Span20). This binary mixture also depicted the lowest viscosity, which is favorable as a carrier agent in drug delivery. The incorporation of various ILs into microemulsions resulted in a particle size ranging from 11 to 39.7 nm at diverse drug loading capacity. The formulation with IL [TEA][OAc] and IL [DEA][OAc] displayed substantial drug carrying capacity and stability compared to the commercially available IL [EMIM][OAc] loaded system.

This paper presents results of tribological research of a composition containing as a base, extract of waste blackberry seeds obtained by extraction under supercritical carbon dioxide conditions with sorbitan esters as additives (sorbitan trioleate (STO) sorbitan monolaurate (MLS) and etoxylated sorbitan monolaurate (EO20MLS)). The influence of the concentration of surfactants on the motion resistance, wear and anti-seize properties of the obtained lubricants was analysed. Two types of tests were performed: seizure, with linear load increase and constant load (four-ball device T02). The obtained test results compared to the results for the base (pure extract) to paraffin oil and rapeseed oil were related. It was found that the addition of sorbitan esters to the extract has a greater effect on the improvement of anti-seizure properties than on the reduction of resistance to movement and wear to the base.

Supplementary data associated with this article can be found, in the online version, at https://doi.org/10.1016/j.foostr.2018.03.003., The effect of different oil phases and low molecular weight organogelators (LMOGs) structures on edible oils was investigated through differential scanning calorimetry (DSC), rheology and small-angle X-ray scattering (SAXS). Different gelators (glyceryl tristearateGT; sorbitan tristearateST; sorbitan monostearateSM and glyceryl monostearate-GM) were tested in medium-chain triglycerides and high oleic sunflower (named MCT and LCT). Systems were thermoreversible and their thermodynamic properties were dependent on the combined effect of the interactions of structurants polar head with other constituents and the sterical effect of their hydrophobic tails. The crystallization onset temperature was higher for GM and SM, possibly due to the lower sterical effect of their tails. However, the corresponding enthalpy and entropy change values were influenced by the hydrophilic head group: glycerol-based organogelator molecules were able to interact strongly than sorbitans, increasing these values. Rheological studies showed that gels produced with LCT were stronger than with MCT. Moreover, cooling and heating cycles showed more than one transition and shear dependence. Stronger structures were more sensitive to temperature, possibly because of their more organized structure that destabilizes more easily with the increase of molecular mobility. These results were in agreement with the SAXS analyses. At 50°C, the stronger networks lost their initial structure, and at 70°C they collapsed. Thus, molecular interactions and structurant self-assembly were dependent on the structurant+solvent combination, leading to different physicochemical properties and thermal stability. It is expected that these results will allow customizing properties of structured oil for diverse applications, spanning from food to cosmetic and pharmaceutical industries., LuizH.FasolinthanksthescholarshipCapes/FCTprogram(349/13) for the research exchange and Rosiane Lopes Cunha thanks CNPq (CNPq 307168/2016-6) for the productivity grant. The authors also would like to thank Fapesp (EMU 09/54137-1), CNPq and Capes for their financial support and the Brazilian Synchrotron Light Laboratory (LNLS) for the opportunity to carry out SAXS measurements. This study was also supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/ 04469/2013 unit and COMPETE 2020 (POCI-01-0145-FEDER-006684) and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020 – Programa Operacional Regional do Norte. and of the Project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462)., info:eu-repo/semantics/publishedVersion

Oil spill dispersants used in the case of subsea release exhibit different efficiencies depending on the nature of oil and the salinity of water. This variability can be rationalized by considering the location of the optimal formulation of the dispersant/oil/water system, in the light of the concepts used for optimizing surfactants blends for other applications, in particular eor (enhanced oil recovery). In practice, the number of commercially-available dispersants is constrained by the thorough studies necessary for their registration, in particular as regards to their fate in the environment. Therefore a fair ability to disperse a wide range of potential spills is generally looked for. We show that the optimal formulation approach can be used to adapt the composition of the surfactant blend – hydrophilic and hydrophobic sorbitan esters and sodium dioctylsulfosuccinate–for the dispersion of different crude oils in waters of given salinities, thus allowing a significant increase in dispersion efficiency with a minimal variation of the overall product composition.

Winterization is one means of improving the low temperature flow properties of biodiesel fuel, by the separation of saturated FAMEs. Additives are also employed to improve separation in the winterization process by modifying the crystallization behavior. This process is referred to as additive winterization. In a previous study, we investigated a novel additive winterization method in which FAMEs are separated without agitation during cooling, allowing improved separation of saturated FAME and unsaturated FAME mixtures. This method is both facile and energy-efficient because vacuum filtration is not required. In this study, we examined the effects of additives (sorbitan mono fatty acids) and agitation on the separation of saturated FAMEs from saturated and unsaturated FAME mixtures via winterization. The additive winterization process resulted in significant improvements in the cloud points of the FAME mixtures following a single separation run, with the cloud point being decreased by 8 K under optimum conditions. In contrast, winterization based on agitation required at least two cycles of sequential cooling, agitation and filtration to obtain similar results. This study therefore highlights the potential of additive winterization using sorbitan mono fatty acid esters to enhance the low-temperature flow properties of biodiesel fuels based on a simple process with reduced energy expenditures.

The selectivity of a novel mineral beneficiation technology utilizing a water in oil emulsion as the binder for mineral agglomeration has been investigated. This novel technology can agglomerate fine and ultrafine hydrophobic mineral particles in less than 7 s thus providing an option for the beneficiation of low-grade ores or rare earth metal oxides, metal sulphides or platinum group metals (PGMs). However, the selectivity of the process is compromised by the interaction of emulsifier-sorbitan mono oleate (SMO), commonly known as Span® 80, with the gangue. SMO is the emulsifier used to make the emulsion binder. In this work, we show that the SMO interacts with the transition metal ions adsorbed on the gangue particles possibly via the sorbitan sugar group thus hydrophobizing and leading to the agglomeration of the gangue. This gangue-SMO interaction reduces the selectivity of the agglomeration process. Treating the ore slurry with ethylene diamine tetraacetic acid (EDTA), prior to agglomeration, prevents the agglomeration of gangue as the EDTA removes the adsorbed metal ions and brings them into the solution. The EDTA treatment is shown to improve the selectivity of the agglomeration process significantly. We also show that SMO can act as a generic collector as it can hydrophobize particles of a variety of transition and rare earth metal oxides.

In the present investigation, proniosomes of risperidone were formulated, optimized and evaluated for effective transdermal delivery in order to overcome the bioavailability issues of orally administered risperidone. The proniosomes were prepared using various sorbitan esters with cholesterol and soya lecithin and were evaluated for in-vitro parameters, ex-vivo permeation and in-vivo performance. Results indicated that the vesicles were spherical in shape, their size ranged from 284.00 nm to 941.40 nm and they had high zeta potential. The entrapment efficiency for spans was higher compared to tweens. DSC and IR studies confirmed the absence of chemical interactions between the risperidone and proniosome components. In-vitro release study showed that formulations with spans exhibit controlled release profile and followed the Higuchi model. No significant change in vesicle size and entrapment efficiency was observed when the proniosomes were stored at 4 ± 1 °C and 25 ± 2 °C for three months. Proniosomes with span 60 showed no signs of erythema or edema and has highest flux across the rat skin (169.851 ± 2.13 μg cmâ2 hâ1). The relative bioavailability was 92% after transdermal administration of proniosomes and the tmax was increased to 8 h. So we conclude that the developed proniosome formulation would be a promising alternative to improve the bioavailability problems of risperidone. Keywords: Risperidone, Proniosomes, Transdermal systems, Atypical antipsychotic, Relative bioavailability