sorbitan-monooleate and sorbitan-monopalmitate

The aim of this study was to prepare and evaluate simvastatin (SIM) loaded elastic provesicular systems for effective topical wound management. SIM provesicles were prepared using the non-ionic surfactant Span 40, cholesterol and three edge activators i.e. Span 80, Tween 80 and sodium cholate. The vesicles revealed high SIM encapsulation efficiency ranging from 87.25 to 98.15%, whereas vesicle sizes ranged from 462.3 to 801.5 nm. Vesicle sizes decreased with increasing the concentration of the edge activator. High negative zeta potential values were observed, revealing good stability of the vesicular formulations. The release of SIM from hydrated provesicular carriers was biphasic in nature. The selected SIM provesicular elastic carrier exerted approximately two-fold increase in the amount of SIM permeated through rat skin, compared to the free drug. Evaluation of wound healing activity of the selected provesicular formulation revealed significant reduction in wound size in rats, fourteen days post-wounding. These results were further confirmed by a significant increase in expression of vascular endothelial growth factor and collagen type I compared to the free drug. These results indicate that provesicular carriers could be a promising drug delivery system for encapsulating SIM and enhancing its wound healing efficacy.

Topics: Animals; Chemistry, Pharmaceutical; Cholesterol; Collagen Type I; Drug Carriers; Drug Liberation; Drug Stability; Hexoses; Male; Particle Size; Polysorbates; Rats; Rats, Wistar; Simvastatin; Sodium Cholate; Vascular Endothelial Growth Factor A; Wound Healing

Cocoa butter crystallization in the presence of sorbitan mono- and triesters or canola oil was investigated. Solid-state surfactant esters accelerated early-stage cocoa butter solidification while suppressing later growth. Sorbitan tristearate showed the strongest effect, followed by sorbitan monostearate and sorbitan monopalmitate. Liquid-state surfactants suppressed cocoa butter crystallization at all time points, with sorbitan trioleate showing a stronger effect than sorbitan monooleate, which behaved in a similar fashion to canola oil. Via DSC, the palmitic and stearic-based surfactants only associated with cocoa butter's high-melting fraction, with the oleic acid-based surfactants and canola oil showing little influence. All sorbitan esters had little effect on polymorphism, whereas canola oil accelerated the form II-to-III-to-IV transition. The palmitic and stearic-based surfactants greatly reduced cocoa butter crystal size whereas the oleic acid-based surfactants and canola showed no notable effect. Overall, sorbitan esters impacted cocoa butter crystallization kinetics, though this depended on surfactant structure and concentration.

Topics: Crystallization; Dietary Fats; Esters; Hexoses; Kinetics; Stearates; Surface-Active Agents

Curcuminoids (curcumin, desmethoxycurcumin, and bisdesmethoxycurcumin) are major bioactive substances found in turmeric (Curcuma longa L.) extracts and possess antioxidant, anti-inflammatory, antimicrobial and anticancer properties. In this study, curcuminoid niosomes prepared with a series of Span non-ionic surfactants were developed to enhance the skin permeation of curcuminoids. Formulations were evaluated based on aggregation of niosomes, curcuminoid loading, % entrapment efficiency and in vitro permeation of curcuminoids through shed snake skin. Optimal formulations of curcuminoid niosomes including sorbitan monooleate, cholesterol, and Solulan C-24 at a mole ratio of 47.5:47.5:5 were obtained. Up to 11 micromoles of curcuminoids could be loaded in the niosome with a % entrapment efficiency of 83%. About 90% of the niosomes had a diameter of 12.25 +/- 5.00 microm. The niosomes significantly enhanced permeation of curcuminoids compared with a methanolic solution of curcuminoids: 4% of entrapped curcuminoids traversed the shed snake skin, whereas permeation from the methanolic solution was undetectable. The fluxes of curcumin, desmethoxycurcumin, and bisdesmethoxycurcumin were 1.117, 0.263, and 0.057 microg/(cm2h), respectively, consistent with the relative hydrophobicity of curcumin > desmethoxycurcumin > bisdesmethoxycurcumin. In conclusion, our data show that curcuminoids can be successfully formulated as niosomes and that such formulations have improved properties for transdermal delivery.

Topics: Animals; Chemistry, Pharmaceutical; Cholesterol; Chromatography, High Pressure Liquid; Curcumin; Hexoses; In Vitro Techniques; Indicators and Reagents; Liposomes; Microscopy, Electron, Scanning; Particle Size; Permeability; Reproducibility of Results; Skin Absorption; Snakes; Surface-Active Agents

A defined change in formulation components affects the physical and chemical characteristics of cationic liposomes (CLs) carriers in many ways. Therefore, a great degree of control can be exercised over the structure by modifying the CLs with various materials, leading to new innovations for carrier improvement. In the present study, surface modifications of cationic liposomes with non-ionic surfactants--sorbitan monoesters serials (Span 85, 80, 40 and 20) were carried out for developing a new gene transfer carrier. Span modified cationic liposomes (Sp-CLs) were prepared by reverse phase evaporation method (RPV) and self-assemble complexes of antisense oligonucleotides/surfactant modifying cationic liposomes were prepared by auto-coacervation through electrostatic effect. Characterization of Sp-CLs and the self-assembled complex was performed by electron microscope, particle size, zeta potential, turbidity and agarose electrophoresis. Furthermore, in vitro cellular uptake experiment showed that Span plays a role in enhancing the cellular uptake of encapsulated oligonucleotides mediated by Sp-CLs by the endocytosis-dependent route. CLs modified with Span 40 significantly facilitated the cellular uptake by COS-7 cells and HeLa cells; also showed some positive effect on gene expression. That suggests it is a potential non-viral carrier for efficient gene transfer.

Topics: Cations; Cell Line; Gene Transfer Techniques; Genetic Vectors; Green Fluorescent Proteins; HeLa Cells; Hexoses; Humans; Liposomes; Microscopy, Electron, Transmission; Nephelometry and Turbidimetry; Surface-Active Agents

Creams from three components, surfactant, purified water and oil, were prepared. Comparable molar fractions of components were used in order to better understand the structural properties of the components used. The surfactants were sorbitan monoesters, sorbitan monolaurate, monopalmitate, monostearate and monooleate, which differed from each other in the length or structure of the hydrocarbon chain. The oils used were isopropylpalmitate and myristate, and they differed from each other in the length of the fatty acid chain. Rheological properties, droplet size distributions and types (either o/w or w/o) of the creams were studied. The rheological tests used were oscillation stress sweep test, creep recovery test and viscosity test. The modelling of the creep phase was based on the creep recovery test. Sorbitan monolaurate and monostearate formed w/o creams, sorbitan monopalmitate and monooleate o/w creams. It appeared that the double-bonded structure of the surfactant made the cream less elastic. Elasticity was increased due to lengthening of the alkyl chain of the surfactant and increased amount of surfactant. Also the lengthening of the fatty acid chain of the oil made the creams more elastic. The results of the rheological tests and droplet size distributions correlated well each other. According to the modelling of the creep phase, creams could be represented either with the Burger model or with the Maxwell model.

Topics: Elasticity; Hexoses; Ointments; Rheology; Surface-Active Agents

Using the analytical constants for sorbitan monolaurate, monopalmitate, monostearate, and monooleate given in the National Formulary (NF), calculations were carried out that indicated that these emulsifiers are esters of sorbitol mono- and dianhydrides. Contrary to the NF description, no significant amount of sorbitol ester was calculated to be present, in agreement with recent experimental findings. Further calculations were made using the NF-defined analytical constants of polysorbate 20, polysorbate 40, polysorbate 60, and polysorbate 80, which indicate that these emulsifiers are esters primarily of polyoxyethylated sorbitol monoanhydride (i.e., sorbitan), with lesser quantities of polyoxyethylated esters of sorbitol dianhydride. Since all hydroxyl groups of the polysorbates are primary, random distribution of acyl groups on the available hydroxyls can be assumed, and the likely composition of these emulsifiers can be calculated. The most abundant compounds appear to be polyoxyethylated sorbitan mono-, di-, and triesters. Although the polysorbates are stated to contain 20 moles of ethylene oxide per mole of ester, the oxyethylene contents stated in the Food Chemicals Codex reveal that somewhat more than 20 moles of ethylene oxide are combined.

Topics: Chemistry, Pharmaceutical; Excipients; Hexoses; Pharmacopoeias as Topic; Polysorbates; United States

A range of surfactants with different hydrophile-lipophile balance (HLB) values was selected to investigate the influence of interfacial properties on the uptake of oil droplets into complex coacervate microcapsules. The well characterized gelatin/acacia complex coacervate system was used in this study and the encapsulation of squalane, and oleic acid was investigated. The surfactants investigated were Span 85, Span 80, Span 40, egg yolk lecithin, and Tween 80. Combinations of surfactants were utilized to obtain intermediate HLB values. The percentage oil encapsulated was determined gravimetrically, based on the initial concentration and the amount extracted from the microcapsules. The aqueous interfacial tension values of the oils and oil/surfactant systems were measured using the Wilhelmy plate method. The interfacial properties were correlated to the percentage oil uptake by the coacervate phase. The relative hydrophobicity/lipophilicity of the oil influenced its uptake by complex coacervate droplets. The presence of surfactant affected oil uptake, depending on the HLB value of the surfactant or surfactant mixture. Uptake of squalane by the gelatin/acacia coacervates was found to be optimized by the addition of surfactants with HLB values in the range 2.5-6. The percentage uptake of oil decreased rapidly for systems prepared containing surfactants with HLB values outside this range. No correlation was observed between oil uptake by the coacervate phase and the interfacial tension of the oil and oil/surfactant systems with double-distilled deionized water.

Topics: Capsules; Drug Compounding; Emulsions; Gelatin; Gum Arabic; Hexoses; Models, Chemical; Oils; Oleic Acid; Oleic Acids; Phosphatidylcholines; Polysorbates; Squalene; Surface Properties; Surface Tension; Surface-Active Agents