Development and characterization of gelatin‐based hydrogels,emulsion hydrogels,and bigels: A comparative study

This study was designed to examine the physicochemical and electrical properties of gelatin‐based hydrogels, emulgels, and bigels. The chemical studies suggested an increase in hydrogen bonding in the emulgel and bigel when sesame oil (SO; representative vegetable oil) and SO organogel (OG; representative OG) were incorporated within the gelatin matrix. The emulgel and bigel showed better mechanical properties and higher electrical impedances compared to the hydrogel. The hydrogel showed similar swelling at pH 1.2 and 7.2. The swelling of the emulgel and bigel was higher at pH 7.2. The formulations were found to be highly hemocompatible; this indicated their biocompatible nature. Ciprofloxacin, a model antimicrobial drug, was incorporated within the formulations. The release of the drug was found to be diffusion‐mediated. The antimicrobial efficiency of all of the drug‐loaded formulations was found to be equivalent. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41502.     

Thermal,electrical, and mechanical properties of tween 80/span 80–based organogels and its application in iontophoretic drug delivery

The present study describes the preparation and characterization of the Tween 80/Span 80 and sunflower oil–based organogels. Organogels were characterized using microscopy, X‐ray diffraction, thermal, mechanical, and electrical techniques. The properties were found to be dependent on the proportion of the water : surfactant mixture. The in vitro drug release studies were performed under electrical potential. The drug release in the presence of electrical current was compared with the passive drug release. The drug release from the organogels followed the zero‐order kinetics suggesting diffusion mediated release. The preliminary results suggested that the organogels may be used as drug carriers in iontophoretic drug delivery. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41419.     

Encapsulation of animal wax‐based organogels in alginate microparticles

Encapsulation of organogels is a novel perspective in the field of controlled drug delivery. This study reports encapsulation of lanolin based organogels within alginate microparticles. The microparticles were prepared by emulsification/internal gelation method. Microscopic studies suggested spherical shape of the microparticles. Fourier transform infrared, X‐ray diffraction and thermal studies confirmed the presence of organogels within the microparticles. Organogels containing microparticles showed improved drug (e.g., salicylic acid and metronidazole) entrapment efficiency. The release of the drugs from the microparticles was dependent on the pH of the dissolution medium. The release was diffusion mediated. The drug loaded microparticles showed antimicrobial activity against E. coli and B. subtilis. The preliminary study suggested that the encapsulation of the organogels may help prolonging the release of the drugs and hence may be tried as vehicles for controlled drug delivery. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40910.     

Structure and Physical Properties of Organogels Developed by Sitosterol and Lecithin with Sunflower Oil

High linoleic acid sunflower oil (HLSO) with various sitosterol (Sit) to lecithin (Lec) mass ratios (i.e., 0:100–100:0) were used to develop organogels at two storage temperatures (T_s: 5 and 25 °C). The results showed that, at 25 °C, the hardness value of organogels obtained from HLSO with both Sit and Lec was higher than that of organogels developed from HLSO with only Sit or Lec. Microscopy revealed that the shapes of the crystals in the organogels varied significantly with the composition of the structurant and the T_s. At both T_s used, the Sit:Lec (80:20) system had a lower degree of supersaturation compared with the (100:0) system. X‐ray diffraction (XRD) revealed that Sit:Lec mass ratio of 70:30, 80:20 and 100:0 had similar short spacings, and the presence of Lec might be adverse to the formation of Sit crystal in oil. Small‐angel X‐ray scattering (SAXS) showed that the layer thickness of Sit/Lec/HLSO organogel was larger than that of Sit/HLSO organogel. It was found that the presence of Lec induced the change of self‐assembly structure of Sit in HLSO and caused the changes of physical properties of organogels obtained.     

Nonionic Mixed Surfactant Stabilized Water-in-Oil Microemulsions for Active Ingredient In Vitro Sustained Release

Olive oil is an excellent dispersing medium for water‐in‐oil microemulsions as it helps hydrate the skin and enhances the release of the active ingredients. In this study, mixed surfactants containing Span^® 80 with varied Tween^® series at 1:1 ratio were prepared with olive oil and water to produce water‐in‐oil microemulsions. The microemulsions were used to study the in vitro release of the active ingredients with different water solubilities. A microemulsion olive oil/water/mixed surfactant (56:4:40 by weight) was selected from the constructed phase diagram for further physical characterization. The analysis showed that the microemulsion composed of Span^® 80 and Tween^® 80 (ST80) was the most suitable surfactant combination. Equal amounts of ascorbic acid, caffeine and lidocaine were solubilized in ST80 microemulsions to study their release rate. Physical evaluation of ST80 microemulsions incorporating the active ingredients showed no apparent change compared to the ST80 microemulsion alone. The in vitro release study showed that the rate of active ingredients released from the microemulsion into the receptor chamber depends on their hydrophobicity, whereby lidocaine and caffeine were fivefold and twice as fast, respectively, with respect to ascorbic acid. ST80 microemulsions show constant rate of active ingredient release, demonstrating the sustained release properties of the system.     

Poly(acrylic acid–sodium styrene sulfonate) organogels: Preparation,characterization, and alcohol superabsorbency

Polymeric organogels based on acrylic acid and sodium styrene sulfonate (SSS) were synthesized and characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, dynamic mechanical thermal analysis (DMTA), and rheometrical analyses. The organogels exhibited medium alcohol absorbency because of counterion binding that formed in solvents with low dielectric constants. After acid treatment, the possibility of counterion binding was decreased, and the organogels achieved superabsorbency in alcohols, for example, about 80 and 50 g/g in methanol and ethanol, respectively. The superabsorbency was also measured in higher alcohols (i.e., n‐propanol and isopropyl alcohol) and polyols (i.e., ethylene glycol, propylene glycol, 1,3‐propanediol, and glycerol). The dielectric constant, viscosity, and structural features of the alcohols were investigated as important parameters determining the alcohol superabsorbency. DMTA of dried samples showed two glass‐transition temperatures (T_g's), that is, the matrix T_g and the complex T_g, which increased with increasing SSS content. The tan δ peak intensity increased after the acid treatment. With increasing SSS, the storage modulus of the dried gel increased; whereas that of the rheometrically measured hydrated gel decreased. Tan δ decreased with increasing SSS because of enhanced counterion binding. These alcohol‐specific superabsorbing organogels are suggested as excellent candidates for the manufacture of products with high alcohol contents, such as hand sanitizers and fuel gels. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Comparison of the pomegranate seed oil organogels of carnauba wax and monoglyceride

The aims of this study were to prepare organogels from pomegranate seed oil (PO) with carnauba wax (CW) and monoglyceride (MG), compare the organogels with a commercial margarine (CM) and evaluate 3 months storage stability. At 3% organogelator addition, no gels were formed, while at 7 and 10% additions, the oil binding capacities increased and were always higher in CW organogels, with crystal formation times of 8.0 to 14.0 min. Solid fat content (SFC) of the CW organogels varied between 2.96 and 8.71% at 20°C, while MG gels had 2.89–9.43%, and CM had 29.73% SFC. The peak melting temperatures of the CW organogels ranged from 74.73 to 75.74°C and MG organogels ranged from 11.09 to 50.63°C, whereas CM product exhibited 45.92°C peak melting temperature. The hardness of CW organogels was higher than that of MG organogels. The organogels showed potential as spreadable products. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41343.     

Thermo‐mechanical properties of candelilla wax and dotriacontane organogels in safflower oil

The thermo‐mechanical properties of organogels developed by a complex mixture of n‐alkanes present in candelilla wax (CW) were investigated and compared with the ones of organogels developed by a pure n‐alkane, dotriacontane (C₃₂). In both cases, the liquid phase used was safflower oil high in triolein (SFO) and the variables studied were two levels of gelator concentration (1 and 3%), cooling rates of 1 and 10 °C/min, and two gel setting temperatures, 5 and 25 °C (T_set). Based on comparisons of the organogels made with C₃₂, the presence of minor molecular components in CW had a profound effect on the crystal habit of the n‐alkanes in CW‐based organogels, and therefore on their physical properties. Thus, independent of the cooling rate and T_set, C₃₂ showed a higher solubility and higher self‐assembly capability in the SFO than CW. Nevertheless, for the same gelator concentration and time‐temperature conditions, C₃₂ organogels had lower G' profiles than CW organogels. Additionally, independent of the type of gelator, more stable organogel structures were developed at T_set = 5 °C and using the lower cooling rate. The rheological behavior of the organogels was explained considering the formation of a rotator phase by the n‐alkanes, its solid‐solid transition, and their dependence as a function of the cooling rate and T_set. The results here obtained showed that it is possible to gelate SFO through organogelation with CW and without the use of trans fats.     

Castor oil and sorbitan monopalmitate based organogel as a probable matrix for controlled drug delivery

The study has been designed to develop and evaluate the in vitro sustained‐release capability of sorbitan monopalmitate (SMP) and castor oil (CO) based organogels. Organogels were prepared by heating the mixture of SMP‐CO at 60°C either with or without using distilled water (DW). The heated mixture was subsequently cooled to room‐temperature to allow the formation of a gelled structure. Characterization of organogels was carried out by microscopy (light, fluorescent, electron, and atomic force), Fourier transform infrared (FTIR) spectroscopy, X‐ray diffraction (XRD), differential scanning calorimetry (DSC), rheological study, pH, impedance spectroscopy, hemocompatibility, and antimicrobial studies. The properties and stability of the gels was dependent on the composition of the organogels. FTIR studies indicated the presence of strong intramolecular/intermolecular hydrogen bonding amongst the gel components. XRD studies suggested amorphous behavior of the gels. The gels showed a shear thinning behavior. Metronidazole (MZ) loaded gels showed good antimicrobial property to be used as an antimicrobial formulation. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 1503–1515, 2013     

Effects of Oleic Acid and Phospholipids on the Formation of Lecithin Organogel and Microemulsion

The formation of organogels and microemulsions of lecithin in the presence of a biocompatible cosurfactant, oleic acid, was studied. Low content of oleic acid ([oleic acid]/[lecithin] < 0.1) in the lecithin–oleic acid–dodecane–water system leads to an expansion of the region of existence and to a decrease in the viscosity of lecithin organogels. At high contents of oleic acid ([oleic acid]/[lecithin] > 0.6), low‐viscosity microemulsion exists in the system. Phosphatidylethanolamine, lysophosphatidylcholine, and other phospholipids that are present as impurities in the commercial samples of soybean lecithin can act as cosurfactants. For the first time, the formation of lecithin organogels in the systems containing commercial samples of soybean lecithin with phosphatidylcholine concentrations of 69.3 wt% (Lipoid S75) and 52.9 wt% (Lipoid S45) and saturated aliphatic hydrocarbons is demonstrated. The gelation is observed at T =25 °C in octane, decane, dodecane, and hexadecane for Lipoid S75 and in dodecane and hexadecane for Lipoid S45. A decrease in the degree of purification of lecithin leads to an expansion of the regions of existence of the organogels and to a reduction of their viscosity.     

Development of an Environmentally Acceptable Detergent Formulation for Fatty Soils Based on the Lipase from the Indigenous Extremophile Pseudomonas aeruginosa Strain

A lipase derived from an indigenous extremophile Pseudomonas aeruginosa strain isolated from rancid metalworking fluid was evaluated as a detergent additive. Applicability of the obtained enzyme as an additive in detergent formulations was confirmed by its implementation in the formulations of several new products differing in surfactant type and concentrations, demonstrating satisfactory performance in terms of degreasing efficiency and composition of the washing wastewater. The degreasing efficiency of different enzyme‐containing detergent formulations was studied on cotton fabric samples stained with triolein and compared to that of formulations containing only surfactant. The highest efficiency of the fatty soil removal in formulations with a low content of surfactants (0.4 %) was noted in the enzyme formulation containing Lutensol^® XP‐80 (degreasing efficiency >80 %) and Triton^® X‐100 (degreasing efficiency >60 %). An attempt was then made to optimize the composition of the enzyme formulation on the basis of one or both of these surfactants using statistically planned experiments and response surface methodology (RSM). Taking into consideration the environmental aspects and the shown detergency, it appeared that rather high degreasing effects were achieved in formulations based on a low quantities of Lutensol^® XP‐80 (0.4 %) at all pH values. However, pH seemed to have a notable effect since the degreasing efficiency significantly increased with increasing pH and the amount of the enzyme. Formulations having a moderate alkaline pH profile and higher amount of enzyme exhibited a high cleaning performance of fatty soil even at a low concentration of the surfactant.     

Development of ionic and non‐ionic natural gum‐based bigels: Prospects for drug delivery application

Recently, much attention has been focused on the development of gel based formulations for controlled drug delivery applications. Herein, we report the effect of the ionic (gum acacia) and the non‐ionic (guar gum) gums on the properties of the bigels prepared with fluid‐filled organogels. The microscopic study suggested the presence of flocculated structure in guar gum bigel, whereas, a de‐flocculated structure was observed in gum acacia bigel. Infrared spectroscopy suggested the presence of polysaccharides in the bigels. The mechanical properties of the guar gum bigel were better than gum acacia bigel. The conductivity and the release properties suggested superior properties of gum acacia bigel. This indicated that the ionic nature of acacia bigel played a major role in controlled drug delivery, making it a potential bigel for desired pharmaceutical applications. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42561.     

多乳状液一种新型化妆品体系

多乳状液体系可被视为一种最为合适的化妆品体系，它可以将有效成分分别溶入多乳状液体系的不同组成相中，并对各有效成分进行缓慢释放。讨论了多乳状液的制备原理并给出几个近来多乳状液研究中得到的稳定体系的例子、多乳状液体系的物理稳定必、粘弹性以及应用前景也将得到一定阐述。     

Optimized Microemulsion Systems for Detergency of Vegetable Oils at Low Surfactant Concentration and Bath Temperature

Triglycerides and vegetable oils are amongst the most difficult oils to remove from fabrics due to their highly hydrophobic nature; this is all the more challenging as cold water detergency is pursued in the interest of energy efficiency. Recently, extended surfactants have produced very encouraging detergency performance at ambient temperature, especially at low surfactant concentration. However, the salinity requirement for extended surfactants was excessive (4–14%) and there is limited research on extended‐surfactant‐based microemulsions for cold water detergency (below 25 °C). Therefore, extended‐surfactant‐based microemulsions are introduced in this study for cold temperature detergency of vegetable oils with promising salinity and surfactant concentration. The overall goal of this study is to explore the optimized microemulsion formulations with low surfactant and salt concentration using extended surfactant for canola oil detergency at both 25 and 10 °C. It was found that microemulsion systems achieved good performances (higher than those of commercial detergents) corresponding to IFT value 0.1–1 mN/m with the surfactant concentration as low as 10 ppm and 4% NaCl at 25 °C, and as low as 250 ppm and 0.1% (1000 ppm) NaCl at 10 °C. In addition, microemulsion systems were investigated with a different salt (CaCl₂, or water hardness, versus NaCl) at 10 °C, demonstrating that 0.025% CaCl₂ (250 ppm) can produce good detergency; this is in the hardness range of natural water. These results provide qualitative guidance for microemulsion formulations of vegetable oil detergency and for future design of energy‐efficient microemulsion systems.     

A novel approach to prepare etoposide‐loaded poly(N‐vinyl caprolactam‐co‐methylmethacrylate) copolymeric nanoparticles and their controlled release studies

A series of copolymeric nanoparticles of methyl methacrylate and N‐vinylcaprolactam were synthesized from microemulsions containing sodium dodecyl sulfate. Etoposide as a model drug was loaded in nanoparticles during in situ polymerization. Stable nanolatex were produced and characterized for size and shape by dynamic light scattering (DLS) and transmission electron microscopy. Particles were found to be spherical in nature with size less than 50 nm. Structural characterization of copolymers was done by infrared and nuclear magnetic resonance spectroscopy. Differential scanning calorimetery (DSC) and X‐ray diffractometry (XRD) techniques were used to evaluate molecular level interaction of etoposide with nanoparticles. Drug encapsulation efficiency was determined by ultraviolet (UV) spectrometry and found to be 35–67%. DSC, XRD, and UV data suggested the molecular level dispersion of drug in the nanoparticles. In vitro release studies and in vitro cytotoxicity showed prolonged and controlled release of etoposide from nanoparticles along with IC₅₀ values of nanoparticles in the range of 0.01–0.1 mg/mL. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2013     

医药剂型在农药中的应用及发展趋向

医药剂型与农药剂犁有许多相通的地方,许多医药剂型已经渗入到农药领域并得到了成功的应用.综述了新剂型及新技术在医药和农药中的应用情况及发展趋向,主要介绍了医药缓控释制剂、片剂、水乳剂、微乳剂以及混悬剂(悬浮剂)在农药中的应用,并对医药新制剂中的分散片、速溶片及渗透泵片在农药领域的应用做了展望,同时指出需审慎对待微乳剂等农药纳米制剂的研发和审批.     

Breaking Water‐in‐Bitumen Emulsions using Polyoxyalkylated DETA Demulsifier

Adding demulsifier is currently the most widely used method for breaking water‐in‐oil emulsions. Experimental demulsifiers based on DETA with various PO and EO contents were synthesized and their RSN values were determined. The dehydration efficiency of these demulsifiers was measured in diluted bitumen using both gravitational settling and centrifugation tests. The results indicate that some of the DETA products could perform potentially at least as well or better than the demulsifier currently used in a commercial plant. RSN values are correlated very well with EO and PO numbers. Optimal dehydration efficiency is in the RSN range of 18 to 22, which corresponds to a PO‐to‐EO ratio in the range of 1 to 1.8.     

Formulation of ultralow interfacial tension systems using extended surfactants

Inspired by the concept of lipophilic and hydrophilic linkers, extended surfactants have been proposed as highly desirable candidates for the formulation of microemulsions with high solubilization capacity and ultralow interfacial tension (IFT), especially for triglyceride oils. The defining characteristic of an extended surfactant is the presence of one or more intermediate-polarity groups between the hydrophilic head and the hydrophobic tail. Currently only limited information exists on extended surfactants; such knowledge is especially relevant for cleaning and separation applications where the cost of the surfactant and environmental regulations prohibit the use of concentrated surfactant solutions. In this work, we examine surfactant formulations for a wide range of oils using dilute solutions of the extended surfactant classes sodium alkyl polypropyleneoxide sulfate (R-(PO) _x −SO₄Na), and sodium alkyl polypropyleneoxide-polyethyleneoxide sulfate (R-(PO) _y -(EO) _z −SO₄Na). The IFT of these systems was measured as a function of electrolyte and surfactant concentration for polar and nonpolar oils. The results show that these extended surfactant systems have low critical micelle concentrations (CMC) and critical microemulsion concentrations (CμC) compared with other surfactants. We also found that the unique structure of these extended surfactants allows them to achieve ultralow IFT with a wide range of oils, including highly hydrophobic oils (e.g., hexadecane), triolein, and vegetable oils, using only ppm levels of these extended surfactants. It was also found that the introduction of additional PO and EO groups in the extended surfactant yielded lower IFT and lower optimum salinity, both of which are desirable in most formulations. Based on the optimum formulation conditions, it was found that the triolein sample used in these experiments behaved as a very polar oil, and all other vegetable oils displayed very hydrophobic behavior. This unexpected triolein behavior is suspected to be due to uncharacterized impurities in the triolein sample, and will be further evaluated in future research.     

Novel carbon‐nanotube‐based organogels as candidates for oil recovery

A simple method for synthesis of novel organogels based on multiwalled carbon nanotubes (MWCNTs) is reported. Three classes of organogels were synthesized by crosslinking polymerization of dodecyl methacrylate with various weight percentages of 1,4‐butanediol dimethacrylate, vinyl‐group‐modified MWCNTs or pristine MWCNTs in the presence of 2,2‐azoisobutyronitrile as initiator. In this reaction, the carbon nanotubes (CNTs) served simultaneously as an adsorbent, a comonomer and a crosslinking agent. The oil‐absorbent containing CNTs showed much higher swelling capacity in oil and organic solvents compared with that without CNTs. Therefore, CNT‐based organogels can be introduced as a promising candidate for environmental protection and oil recovery. © 2012 Society of Chemical Industry     

Perilla Oil Reduces Fatty Streak Formation at Aortic Sinus via Attenuation of Plasma Lipids and Regulation of Nitric Oxide Synthase in ApoE KO Mice

Consumption of n‐3 polyunsaturated fatty acids (PUFA) is associated with a reduced incidence of atherosclerosis. Perilla oil (PO) is a vegetable oil rich in α‐linolenic acid (ALA), an n‐3 PUFA. In this study, antiatherogenic effects and related mechanisms of PO were investigated in atherosclerotic mice. Apolipoprotein E knockout (ApoE KO) mice (male, n = 27) were fed high‐cholesterol and high‐fat diets containing 10 % w/w lard (LD), PO, or sunflower oil (SO) for 10 weeks. Plasma triglyceride, total cholesterol, and low‐density lipoprotein cholesterol concentrations reduced in the PO and SO groups compared to the concentrations in the LD group (P < 0.05). The PO group showed reduced fatty streak lesion size at the aortic sinus (P < 0.05) compared to the sizes in the LD and SO groups. A morphometric analysis showed enhancement of endothelial nitric oxide synthase expression and reduction of inducible nitric oxide synthase expression in the PO group compared to that in the LD group (P < 0.05). Furthermore, aortic protein expression of intercellular cell adhesion molecule 1 and vascular cell adhesion molecule 1 was diminished in the PO group compared to that in the LD and SO groups (P < 0.05). These findings suggested that PO inhibited the development of aortic atherosclerosis by improving the plasma lipid profile, regulating nitric oxide synthase, and suppressing the vascular inflammatory response in the aorta of ApoE KO mice.