Surfactant Composition Research Articles

Experimental studies of the capillary desaturation curve in polymer-surfactant flooding

The paper presents the results of laboratory studies of polymer-surfactant flooding on core samples of different permeability. The obtained data are used in hydrodynamic modeling.
 Experimental studies included:
 • study of the dynamics of oil displacement, plotting the dependence of the residual oil saturation on the surfactant concentration – interfacial tension at the interface of the surfactant-oil solution;
 • comparative experimental studies of residual oil saturation when oil is displaced by surfactant compositions of various manufacturers;
 • comparative studies of phase permeability in flood experiments for the filtration of oil and water, oil and polymer-surfactant solution at different ratios in the flow.

Effect of pH on the Structure and Dynamics of Wormlike Micelles in an Amino Acid-Derived Surfactant Composition.

We studied the impact of pH as a thickening mechanism on the structure and dynamics of wormlike micelles in a mixture of sodium lauroyl sarcosinate (SLSar) and cocamidopropyl hydroxysultaine (CAHS). The viscoelastic properties were obtained using mechanical rheometry and diffusing wave spectroscopy, which provided access to a wide range of frequencies. By using a mesoscopic simulation method [Zou; Larson. J. Rheol. 2014, 58 (3), 681-721], characteristic micelle lengths and times were extracted including contour length, persistence length, entanglement length, reptation time, breakage time, breakage rate, and breakage rate constant. The interplay of pH-dependent reptation times (10-1000 ms) and breakage times (4-38 ms) leads to a minimum in the ratio of reptation time to breakage time of about 0.02 at pH 4.8. This minimum was closely associated with the sharp increase and decrease of the observed viscosity maximum at pH 4.8 in this system. These values may be contrasted with much longer breakage times (20-300 ms) that have been measured in more easily thickened sulfate-based systems. The low breakage times of the SLSar/CAHS system were attributed to the high and pH-sensitive breakage rate constants (0.01-0.17 ms-1 μm-1).

Preparation Technology of Water Based Detergent for Q235 Carbon Steel

Q235 carbon steel is smelted by a converter or open-hearth furnace. However, it is always speckled with oil in the manufacturing process influencing its use performance. In the paper, a water-based detergent, a variety of surfactants and additives, was used to remove the oil. First, the three remarkable surfactants were selected through single-factor experiment. Then, surfactants composition was obtained by simplex formula design. Finally, the optimum formula of metal cleaner was obtained by the uniform experimental design: FMEE 1%, MOA5 2.4%, 6501 2.6%, foam inhibitor 3%, antirust agent 2.4%+AES 2%+ carboxylic acid inhibitor 1.7%+copper corrosion inhibitor 2.1%+ detergent auxiliary 1.9%+water 80.9%. The cleaning efficiency can reach more than 98%.

Experimental Study on Enhancing Wellbore Stability of Coal Measures Formation with Surfactant Drilling Fluid

The phenomenon of self-cleavage of coal and rocks leads to poor continuity and a high degree of heterogeneity of the coal-rock matrix, causing the wellbore in the process of drilling. The problem of wellbore stability in the drilling process of the coal strata has become one of the key scientific problems. To solve the problem, single-agent optimization and compounding tests of surfactants have been carried out. Based on the test results, the surfactant compounding composition has been selected, which can effectively reduce the surface tension of the drilling fluid and increase the contact angle between the drilling fluid and the coal and rock surface. To evaluate the effect of the drilling fluid wettability on wellbore stability of the coal measures strata, the expansibility test, rolling recovery test, and shale pressure transfer test have been carried out, combined with the basic performance tests of the water-based drilling fluid. The results show that the composite surfactant can effectively reduce the surface tension of the drilling fluid by 80.83% and increase the contact angle with coal by 54.17%. The recovery rate of the composite surfactant water-based drilling fluid is as high as 96.2%. The compound surfactant drilling fluid can significantly slow down the transfer rate of shale pore pressure, reduce the invasion degree of the drilling fluid to coal and rock matrix, prevent hydration erosion, and effectively enhance the stability of coal and rock sidewall.

Ultrasound-assisted synthesis and characterization of sesame oil based nanoemulsion

Nanoemulsions are emulsions having droplet sizes in the nanometre range. Nano emulsions have unique properties such as robust stability, transparent nature, high surface area, and tunable rheology. The present study focuses on the synthesis of sesame oil-based nanoemulsion using ultrasonic emulsification to break down particle size to nanometric range. The method uses small surfactant concentration and low energy to synthesize homogenous nanoemulsion. The emulsion is stabilized using Tween 20 surfactant. Aqueous nanoemulsion samples were prepared using sesame oil by varying the surfactant concentration to determine the most stable composition, and different properties of each sample prepared, were analyzed. The ultrasonication time was also varied to study the impact of sonication time. Nanoemulsions formed were then evaluated for their various properties. The droplet size and zeta potential for all samples were determined by the Dynamic Light Scattering technique wherein the best nanometer size distribution was found to be at 1:3 (oil: surfactant) composition. The physical stability was determined using a centrifuge at 3000 rpm. Conductivity, pH, and density of the samples were then measured. A polydispersity index of 0.514 was obtained for the sample of oil: surfactant ratio 1:3. Fourier Transform Infrared Spectroscopy studies were conducted for all samples.

Effect of triton-X100 on ternary complexes of cobalt (II), nickel(II),copper (II) & zinc(II) with aspartic and citric acids

A computer based investigation has been made pH-metrically on the chemical speciation of mixed ligand complexes in ternary systems consisting of cobalt (II) nickel(II), copper (II) and zinc (II) with aspartic and citric acids in triton- X 100 micellar media. The trend of the variation in the stability constants with changing dielectric constant as well as mole fraction of the medium is explained based on the electrostatic interactions of the side chains of the ligands, charge neutralization, chelate effect, stacking interactions and hydrogen bonding. The existence of different ternary species is established from modelling studies using the computer program MINIQUAD75. Distribution diagrams with pH at different compositions of surfactant and structures of plausible ternary complexes are presented.

Formulation and Physical Characterization of Essential Oil Bangle (Zingiber cassumunar Roxb.) Nanoemulsion Gel

Background: Bangle rhizome (Zingiber cassumunar Roxb) essential oil as long been used by Indonesian and often used by postpartum women, as a treatment for abdominal obesity. The formulation of bangle essential oil into topical preparations has not been widely reported. So far, bangle essential oil is not available in pharmaceutical dosage form. The users immediately apply essential oil to the abdominal area and previous study showed that the terpinene-4-ol only diffused 0,39% from 2 mg/cm2 of Bangle essential oil through skin membrane. The development of topical bangle essential oil is necessary to increase the effectiveness of the delivery of active substances through the skin and the comfort of the user. In order to increase the penetration of the terpinen-4-ol, the Bangle essential oil was formulated in the form of a nanoemulsion and then the nanoemulsion was dispersed into a gel base to increase user convenience. Aim: The aim of the present study was to investigate the potential of nanoemulsion formulations for Bangle essential oil and to know the optimum the composition of surfactants and cosurfactants in nanoemulsion system. This study also aims to determine the effect of base gel used in the nanoemulsion gel formulation on the appropriate physical properties. Method: The pre-emulsion was made beforehand with oil and a mixture of surfactant and cosurfactant. With the help of a Design Expert® ver. 10.0.1 software, component of sufactant and co-surfactant were optimized. The design formula was divided into seven nanoemulsion formulas with a ratio of Polysorbate 80: PEG 400, F1 (1: 8), F2 (8: 1), F3 (6,25: 2,75), F4 (8: 1), F5 (1: 8), F6 (1: 8), F7 (4,5: 4,5). The optimum consentration of Polysorbate 80 as surfactant and PEG 400 as co-surfactants in Bangle essential oil nanoemulsion was analyzed using simplex lattice design methode. The optimal formula was further evaluated for its distribution, droplet size, and zeta potential. Distilled water was used as the aqueous phase in nanoemulsion. The amount of aqueous phase: the amount of pre-emulsion is 9 : 1. The optimum nanoemulsion formula then dispersed in carbophol hydrogel to be nanoemulsion gel. Physical characterization of Bangle nanoemulsion gel like a pH, adhesion power, spreadability, viscosity before and after cycling test had been investigated. Result: The optimum composition of surfactant Tween 80 and co-surfactan PEG 400 was 7.659: 1.34. The results showed that the optimal formula with 2% Bangle Essential Oil Loaded in Nanoemulsion had the Z-average 95,2 nm with Index Polidispersity 0,176 and Zeta Potensial -0,1 mV. Bangle Nanoemulsion-Gel had a homogenous organoleptic, spreadability in 6,69 + 0.85 cm, adhesion power in 2.14 + 0.29 seconds, viscosity 5969 + 32.03 cps, and pH 6,58 + 0,29. Conclusion: Bangle Essential Oil Nanoemulsion-Gel formulation has the good physical characteristics and potentially be used as topical dosage forms. A further study is needed to determine the effectiveness of the treatment of abdominal obesity by topical administration of this preparation.

Dynamic Coloration of Complex Emulsions by Localization of Gold Rings Near the Triphase Junction.

Multiphase microscale emulsions are a material platform that can be tuned and dynamically configured by a variety of chemical and physical phenomena, rendering them inexpensive and broadly programmable optical transducers. Interface engineering underpins many of these sensing schemes but typically focuses on manipulating a single interface, while engineering of the multiphase junctions of complex emulsions remains underexplored. Herein, multiphilic triblock copolymer surfactants are synthesized and assembled at the triphase junction of a dynamically reconfigurable biphasic emulsion. Tailoring the linear structure and composition of the polymer surfactants provides affinity to each phase of the complex emulsion (hydrocarbon, fluorocarbon, and continuous water phase), yielding selective localization of polymers around the triphase junction. Conjugation of these polymers with gold nanoparticles, forming structured rings, affords a dynamic reflected isotropic structural color that tracks with emulsion morphology, demonstrating the uniquely enabling nature of a functionalized triphase interface. This color is the result of interference of light along the internal hydrocarbon/fluorocarbon interface, with the gold nanoparticles scattering and redirecting light into total internal reflection competent paths. Thus, the functionalization of the triphase junction renders complex emulsions colorimetric sensors, a powerful tool toward sensitive and simple sensing platforms.

Nanoemulsions of Satureja montana Essential Oil: Antimicrobial and Antibiofilm Activity against Avian Escherichia coli Strains.

Satureja montana essential oil (SEO) presents a wide range of biological activities due to its high content of active phytochemicals. In order to improve the essential oil’s (EO) properties, oil in water nanoemulsions (NEs) composed of SEO and Tween-80 were prepared, characterized, and their antimicrobial and antibiofilm properties assayed against Escherichia coli strains isolated from healthy chicken. Since surfactant and oil composition can strongly influence NE features and their application field, a ternary phase diagram was constructed and evaluated to select a suitable surfactant/oil/water ratio. Minimal inhibitory concentration and minimal bactericidal concentration of NEs, evaluated by the microdilution method, showed that the SEO NE formulation exhibited higher inhibitory effects against planktonic E. coli than SEO alone. The quantification of biofilm production in the presence of NEs, assessed by crystal violet staining and scanning electron microscopy, evidenced that sub-MIC concentrations of SEO NEs enable an efficient reduction of biofilm production by the strong producer strains. The optimized nanoemulsion formulation could ensure food safety quality, and counteract the antibiotic resistance of poultry associated E. coli, if applied/aerosolized in poultry farms.

Antifungal Activity of Topical Microemulsion Containing Ziziphus spina-christi L. for the Treatment of Fungal Vaginitis

Background: vulvovaginal candidiasis (VVC) caused by Candida albicans and other Candida species are high-risk event in patients admitted to hospital. Ziziphus genus is a rich source of medicinal compounds, effective for the treatment or prevention of some diseases. Objectives: This study aimed to evaluate the antifungal effect of topical microemulsion containing Ziziphus spina-christi L (ZSC) extracts against Candida spp.Methods: Z. Spina-Christi was collected and extracted in a Soxhlet apparatus using the ethanol and methanol solvents. Microemulsions were formulated by varying the composition of surfactant (Tween 80) along with cosurfactant (propylene glycol), oil, and water and were characterized regarding their stability. The microemulsion without extract as placebo and the active microemulsion containing ZSC extract as active formulation were applied to test the antifungal activity against C. albicans, C. parapsilosis and C. krusei using well diffusion test. The optimal microemulsion was selected and then analyzed for average diameter of droplets, pH, viscosity and zeta potential.Results: The microemulsion containing ZSC ethanolic extract had a significant inhibitory effect on the different species of Candida, but the most inhibitory effect was found against C. albicans. Conclusion: The results of this study indicate that the ethanol extract has interesting antimicrobial properties and can used for the treatment of fungal infections. More research is required to check this plant performance to treat the Candidiasis.

Side streams from the vegetable oil production as feedstock for surfactants and treir derivative technical systems

This work conducts a technical analysis of the current production and consumption of vegetable oils and some of the oily byproducts to determine the potential feedstock for the synthesis of non-food-competitive surfactants and surfactant-based systems. It defines the concentrated phosphatides (phosphatidic sludge) as no-/low- value streams, appropriately suited for chemical valorisation. The study further creates biobased surfactants by amidation of phosphatidic sludge derived from refinery of sunflower and rapeseed oils with monoethanolamine, N-(2-hydroxyethyl)ethylenediamine, or N,N’-bis(2-hydroxyethyl)ethylenediamine, under the action of calcium hydroxide as catalyst in excellent yields (95–98 %). Besides waste remediation, the use of phosphatides enabled to create the mixed surfactant compositions, comprising fatty acid alkanolamides and calcium glycerolphosphatides with improved solubility in organic non-polar solvents. With new surfactants, there have been created reversed emulsion systems, which can be potentially applied to the development and exploitation of gas and oil deposits are recommended for drilling wells, the disclosure of productive strata; perforation of wells and development of productive layers; blockage of gas, gas condensate and oil wells; elimination of manifestations and flow of gas in wells; limitation and elimination of waterways; cleaning of the hollow zone of wells and intensification of the inflow of hydrocarbon raw materials, which have been tested in laboratory and experimental industrial conditions, and a significant part of them have been introduced or tested on gas condensate fields. Creation of coordinated, effective and economical actions that should be formed in the state energy policy of Ukraine would facilitate the development of oil and gas companies, namely: increase of own oil and gas production; maximizing the potential of energy saving; diversification of external sources of supply; approximation of the parameters of the oil and gas industry to the norms and standards of the European Union.

Современные методы снижения испарения и обеспечения безопасности при хранении нефтепродуктов в резервуарах

Introduction. With long-term storage of gasoline in large-capacity tanks, the problem associated with their volatility becomes urgent. Evaporation of petroleum products and gasoline leads to a change in their physical and chemical properties, a decrease in the yield of light petroleum products during oil refining, and a deterioration in the performance characteristics of engines. In this regard, it becomes difficult to start engines, their reliability, fuel consumption increases and the service life is reduced. Lost light hydrocarbons pollute the environment and increase the fire hazard of enterprises. The aim of the work is to identify effective, inexpensive and safe methods for reducing the volatility of oil products, including gasoline, when stored in tanks. Research methods. A retrospective analysis of studies on the problems of reducing losses of petroleum products during their storage, transportation and use is carried out. Technical and organizational methods for reducing the evaporation of fuels and the use of chemical additives as an inexpensive and effective method for solving the problem of the volatility of gasolines are considered. The conclusion about the efficiency of using chemical additives to fuels to reduce volatility has been substantiated. Results and their discussion. Conclusions are made about the possibility of using surfactants as additives to reduce the evaporation of gasolines during long-term storage in tanks. The analysis of the main components and methods for the synthesis of surfactant compositions capable of creating a surfactant film at the liquid-atmosphere interface, which protects the liquid from evaporation. Conclusion. Reducing the volatility of gasoline with the use of inexpensive and effective additives introduced into the fuel in small quantities, not only reduces the explosion and fire hazard during storage in large tanks, reduces losses, but also prevents the negative impact on the environment from the ingress of low molecular hydrocarbons into it. Key words: volatility of petroleum products, losses during storage of gasoline, methods of reducing volatility, additives.

Dietary Carbohydrates and Fat Induce Distinct Surfactant Alterations in Mice.

Obesity and type 2 diabetes are nutrition-related conditions associated with lung function impairment and pulmonary diseases; however, the underlying pathomechanisms are incompletely understood. Pulmonary surfactant is essential for lung function, and surfactant synthesis by AT2 (alveolar epithelial type 2) cells relies on nutrient uptake. We hypothesized that dietary amounts of carbohydrates or fat affect surfactant homeostasis and composition. Feeding mice a starch-rich diet (StD), sucrose-rich diet (SuD), or fat-rich diet (FaD) for 30 weeks resulted in hypercholesterolemia and hyperinsulinemia compared with a fiber-rich control diet. In SuD and FaD groups, lung mechanic measurements revealed viscoelastic changes during inspiration, indicating surfactant alterations, and interfacial adsorption of isolated surfactant at the air-liquid interface was decreased under FaD. The composition of characteristic phospholipid species was modified, including a shift from dipalmitoyl-phosphatidylcholine (PC16:0/16:0) to palmitoyl-palmitoleoyl-phosphatidylcholine (PC16:0/16:1) in response to carbohydrates and decreased myristic acid-containing phosphatidylcholine species (PC14:0/14:0; PC16:0/14:0) on excess fat intake, as well as higher palmitoyl-oleoyl-phosphatidylglycerol (PG16:0/18:1) and palmitoyl-linoleoyl-phosphatidylglycerol (PG16:0/18:2) fractions in StD, SuD, and FaD groups than in the control diet. Moreover, mRNA expression levels of surfactant synthesis-related proteins within AT2 cells were altered. Under the StD regimen, AT2 cells showed prominent lipid accumulations and smaller lamellar bodies. Thus, in an established mouse model, distinct diet-related surfactant alterations were subtle, yet detectable, and may become challenging under conditions of reduced respiratory capacity. Dietary fat was the only macronutrient significantly affecting surfactant function. This warrants future studies examining alimentary effects on lung surfactant, with special regard to pulmonary complications in obesity and type 2 diabetes.

Wettability Alteration and Adsorption of Mixed Nonionic and Anionic Surfactants on Carbonates.

Mixed-surfactant systems consisting of secondary alcohol ethoxylates and anionic sulfonates are evaluated as wettability alteration agents for enhanced oil recovery. The cloud points of the nonionic surfactants are raised by the addition of the sulfonates. The oil/water interfacial tension and contact angles of oil on initially oil-wet calcite are reported at different temperatures and surfactant compositions. Adsorption experiments are performed for select mixed systems at high temperatures. The extent of the increase in the cloud point, changes in the contact angle, and adsorption are influenced by co-surfactants, surfactant concentrations, and temperatures. Mixed surfactant systems were identified which modified the oil-wet surface to a water-wet surface with final contact angles as low as 70°. Mixed surfactants exhibit a linear trend in adsorption and wettability alteration with the thermodynamic descriptor of cloud point temperature difference, which has been used previously for single surfactants. These findings enable the design of surfactant formulations for wettability alteration in high temperature, high salinity reservoirs.

ROSUVASTATIN CALCIUM PRONIOSOME POWDER: A NOVEL APPROACH TO IMPROVE INTESTINAL ABSORPTION AND BIOAVAILABILITY

Objective: The main objective of the present study was to develop proniosomal formulations to enhance the oral bioavailability of rosuvastatin calcium by improving solubility, dissolution, and/or intestinal permeability.
 Methods: Proniosomal powder formulations were prepared with rosuvastatin calcium drug varying the Span 40 and cholesterol ratio in the range of 0.8:0.2–0.2:0.8 using maltodextrin as carrier by slurry method. The prepared proniosomal powder was filled into capsules. The bioavailability enhancement of proniosomes loaded with drug was studied focusing on non-ionic surfactants composition and drug:Span 40 ratio. Prepared proniosomes were characterized for their particle size distribution, zeta potential, entrapment efficiency, in vitro dissolution study, and thermal characteristics to understand the phase transition behavior. Further, the formulated proniosomes were subjected to stability behavior, ex vivo permeation studies using rat intestine followed by in vivo studies.
 Results: Physicochemical studies help in optimization of formulations. Enhancement in dissolution is due to incorporation of rosuvastatin calcium into the non-ionic surfactant and change in the physical state from crystalline to amorphous, thus improving oral bioavailability. Ex vivo studies show significant permeation enhancement across gastrointestinal membrane compared to control.
 Conclusion: Proniosomes provide a powerful and functional way of distribution of inadequately soluble rosuvastatin calcium drug which is proved from in vivo studies based on the enhanced oral delivery.

Influence of oil phase, surfactant on nano-emulsion based on essential oil from orange using phase inversion temperature method

Essential oils are incredibly effective natural antimicrobials, and they have the potential for substitute synthetic antimicrobials in the food industry, but the use of essential oils is restricted by their little solubility in water. In this research, the phase inversion temperature (PIT) method was employed to produce essential oil from orange nano-emulsions. The effects of oil phase composition, surfactant, and storage condition on the formation and stability of the nano-emulsions were investigated. Study results showed that the surfactant and oil phase constitution highly influenced the thermal property of the nano-emulsions. The transparent nano-emulsions system with the least average droplet size (46.5 nm) was created in the conditions: 10 wt% tween 80, 8 wt% essential oil from orange, 2 wt% coconut oil, and distilled water. The mean droplet diameter of these nano-emulsions raised over time and depended on the composition of surfactants. The nano-emulsion systems contained 10% tween 80 gained small size and stability after 30 days of storage, while systems with 20% tween 80 showed instability, and particle size increased rapidly after 30 days of storage. These outcomes of this investigation could be useful for the fabrication and use of nano-emulsions as distribution systems in food technology.

Preparation and polishing properties of water-based magnetorheological chemical finishing fluid with high catalytic activity for single-crystal SiC

A water-based high catalytic activity magnetorheological chemical finishing fluid (HCAMRCFF) was prepared and modified to enhance the chemical action strength in magnetorheological chemical finishing (MRCF) for single-crystal SiC. The fluid consisted of ferroferric oxide (Fe3O4) and chromium (Cr), deionized water (DW), polyethylene glycol (PEG) and oleic acid, and hydrogen peroxide (H2O2) as the composite catalyst particles, base carrier liquid, surfactants, and oxidant, respectively. HCAMRCFFs with different component concentrations were used to modify via evaluating their catalytic activity. Moreover, the MRCF experiments on SiC were conducted using the prepared HCAMRCFFs. The results show that the catalytic activity increases with an increase in the oxidant concentration. Furthermore, composite catalysts and composite surfactants can significantly improve their catalytic activity. The catalytic activity also increases with an increase in the concentration of composite catalysts. In the composite catalysts, increasing the Cr concentration can significantly enhance the catalytic performance. Composite surfactants can exert the relative superiority to enhance the catalytic activity. Compared with the unmodified finishing fluid, the catalytic activity of modified HCAMRCFF increases by 65.4%; the material removal rate (MRR) of SiC increases by 72.5% up to 635.621 nmh−1, and a surface with a roughness of 0.33 nm is obtained.

FORMULATION AND EVALUATION OF OPTIMISED MALTODEXTRIN BASED PRONIOSOME POWDERS CONTAINING BAZEDOXIFENE ACETATE FOR ORAL DELIVERY

Objective: The main objective of the present study was to develop proniosomal formulations to enhance the oral bioavailability of bazedoxifene acetate by improving solubility, dissolution and/or intestinal permeability.
 Methods: Proniosomal powder formulations were prepared with bazedoxifene acetate drug varying the span 40 and cholesterol ratio in the range of 0.8:0.2 to 0.2:0.8 using maltodextrin as a carrier by slurry method. The prepared proniosomal powder was filled into capsules. The bioavailability enhancement of proniosomes loaded with drug was studied focusing on non-ionic surfactants composition and drug: span 40 ratio. Prepared proniosomes were characterized for their particle size distribution, zeta potential, entrapment efficiency, in vitro dissolution study and thermal characteristics to understand the phase transition behavior. Further, the formulated proniosomes were subjected to stability behavior, ex vivo permeation studies using rat intestine followed by in vivo studies.
 Results: Physico-chemical studies help in the optimization of formulations. Enhancement in dissolution is due to the incorporation of bazedoxifene acetate into the non-ionic surfactant and change in the physical state from crystalline to amorphous, thus improving oral bioavailability. Ex vivo studies show significant permeation enhancement across the gastrointestinal membrane compared to control.
 Conclusion: In conclusion, proniosomes provide a powerful and functional way of the distribution of inadequately soluble bazedoxifene acetate drug, which is proved from in vivo studies based on the enhanced oral delivery.

Highly Sustained Release of Bactericides from Complex Coacervates.

Materials for preventing harmful bacterial contamination attract widespread interest in areas that include healthcare, home/personal care products, and crop protection. One approach to achieving this functionality is through the sustained release of antibacterial compounds. To this end, we show how putty-like complex coacervates, formed through the association of poly(allylamine hydrochloride) (PAH) with pentavalent tripolyphosphate (TPP) ions, can provide a sustained antibacterial effect by slowly releasing bactericides. Using triclosan (TC) as a model bactericide, we demonstrate that, through their dispersion in the parent PAH solution with nonionic surfactants, hydrophobic biocides can be efficiently and predictably encapsulated within PAH/TPP coacervates. Once encapsulated, the bactericide can be released over multiple months, and the release rates can be readily tuned by varying the bactericide and surfactant compositions used during encapsulation. Through this release, the PAH/TPP coacervates provide sustained bactericidal activity against model Gram-positive and Gram-negative bacteria (Staphylococcus aureus and Escherichia coli) grown under a nutrient-rich condition over at least two weeks. Thereafter, though some partial activity persists after one month, the release slows down and the bactericide-eluting coacervates lose their efficacy. Overall, we show that bactericide release from easy-to-prepare complex coacervates can provide a pathway to sustained disinfection.

ENHANCED INTESTINAL ABSORPTION AND BIOAVAILABILITY VIA PRONIOSOMES FOR BAZEDOXIFENE ACETATE DRUG

Objective: The main objective of the present study was to develop proniosomal formulations to enhance the oral bioavailability of bazedoxifene acetate by improving solubility, dissolution and intestinal permeability.
 Methods: Proniosomal powder formulations were prepared with bazedoxifene acetate drug varying the span 60 and cholesterol ratio in the range of 0.8:0.2 to 0.2:0.8 using maltodextrin as carrier by slurry method. The prepared proniosomal powder was filled into capsules. The bioavailability enhancement of proniosomes loaded with drug was studied focusing on non-ionic surfactants composition and drug: span 60 ratio. Prepared proniosomes were characterized for their particle size distribution, zeta potential, entrapment efficiency, in vitro dissolution study and thermal characteristics to understand the phase transition behavior. Further, the formulated proniosomes were subjected to stability behavior, ex vivo permeation studies using rat intestine followed by in vivo studies.
 Results: Physico-chemical studies among various formulations helped in optimization of batch. Good flow properties confirmed from angle of repose values indicate easy filling into capsules. Enhancement in dissolution is due to incorporation of bazedoxifene acetate into the non-ionic surfactant and change in the physical state from crystalline to amorphous, thus improving oral bioavailability. Solid state characterization studies prove the transformation to amorphous form with small particle size improving permeation. No drug excipient interaction was observed and sample is stable in refrigerated conditions. Ex vivo studies show significant permeation enhancement across gastrointestinal membrane compared to control. Invivo studies proved enhanced absorption of bazedoxifene acetate drug by oral route.
 Conclusion: In conclusion, proniosomes provide a powerful and functional way of distribution of inadequately soluble bazedoxifene acetate drug which is proved from in vivo studies based on the enhanced oral delivery.