New pectin derivatives with antimicrobial and emulsification properties via complexation with metal-terpyridines.

Pectin is widely used in food and pharmaceutical industries. However, due to its polysaccharide nature it lacks antimicrobial activity. In the current work, new pectin derivatives with interesting optical and antimicrobial properties were prepared via supramolecular chemistry utilizing Fe- or Cu-terpyridine (Tpy-Fe and Tpy-Cu) motifs. To proof derivatization of pectin, ultraviolet-visible spectroscopy (UV-Vis) and Fourier Transform infrared (FTIR) were used. In addition, the prepared pectin derivatives retained the known emulsification activity of the non-modified sugar beet pectin as seen from the particle size analysis of oil-in-water emulsions. The prepared derivatives showed antibacterial activity toward selected Gram-positive and Gram-negative bacteria. In addition, cytotoxicity test showed that the Tpy-Fe-pectin derivative was non-toxic to cells of human hepatocarcinoma, breast adenocarcinoma MCF7, and colorectal carcinoma cells at concentrations up to 100 µg/ml, while Tpy-Cu-pectin had moderate toxicity toward the aforementioned cells at the same concentration levels. The prepared derivatives could have potential applications in emulsions with antibacterial activity.

Design and evaluation of self-nanoemulsifying drug delivery systems (SNEDDSs) for senicapoc.

Senicapoc (SEN), a potent antisickling agent, shows poor water solubility and poor oral bioavailability. To improve the solubility and cell permeation of SEN, self-nanoemulsifying drug delivery systems (SNEDDSs) were developed. Capryol PGMC®, which showed the highest solubilization capacity, was selected as the oil. The self-emulsification ability of two surfactants, viz., Cremophor-EL® and Tween® 80, was compared. Based on a solubility study and ternary phase diagrams, three optimized nanoemulsions with droplet sizes less than 200 nm were prepared. An in vitro dissolution study demonstrated the superior performance of the SNEDDS over the free drug. During in vitro lipolysis, 80% of SEN loaded in the SNEDDS remained solubilized. An in vitro cytotoxicity study using the Caco-2 cell line indicated the safety of the formulations at 1 mg/mL. The transport of SEN-SNEDDSs across Caco-2 monolayers was enhanced 115-fold (p < 0.01) compared to that of the free drug. According to these results, SNEDDS formulations could be promising tools for the oral delivery of SEN.

The Emulsifying Properties of Hydrogenated Rosin Xylitol Ester as a Biomass Surfactant for Food: Effect of pH and Salts.

The xylitol ester of hydrogenated rosin (XEHR) was obtained for the first time from biomass-based hydrogenated rosin and xylitol using an environmentally friendly, high-pressure CO2 catalytic synthesis. This compound is intended for use as an emulsifier for food. Analyses by ICP-AES showed the absence of heavy metal residues in the product, such that it met food standards. Fourier transform infrared and nuclear magnetic resonance spectroscopies together with gel permeation chromatography confirmed the successful esterification and the formation of a monoester and diester with molar masses of 427 and 772 g/mol. The emulsification of water/soybean oil mixtures by adding the XEHR was assessed at pH values of 4, 6.86, and 10 and in the presence of NaCl, KCl, MgCl2, and CaCl2. The XEHR was found to act as an emulsifier by reducing the interfacial tension of such mixtures to less than 2 mN/m under all conditions. The highest emulsifying activity index (9.52 m2/g) and emulsifying stability index (94.53%) were obtained after adding MgCl2 (100 mM). Particle size and confocal microscopy showed that the presence of salts gave a more uniform droplet size and a finer emulsion structure. The high viscosities of the emulsions containing salts also suggested a more cohesive oil droplet network.

Lipid Nanoemulsions of Rebamipide: Formulation, Characterization, and In Vivo Evaluation of Pharmacokinetic and Pharmacodynamic Effects.

Rebamipide has low oral bioavailability (10%) due to its low solubility and permeability. Lipid nanoemulsions (LNEs) were prepared in order to improve its oral bioavailability. Rebamipide-loaded lipid nanoemulsions were formulated by hot homogenization and ultrasonication method. Olive oil and egg lecithin in various concentrations as emulsifier were used in the preparation of LNEs. The lipid nanoemulsions were evaluated for various parameters. The globule size, polydispersity index (PDI), and zeta potential (ZP) of the formulations ranged from 230.3 ± 3.88 to 279.8 ± 5.76 nm, 0.204 ± 0.008 to 0.246 ± 0.029, and - 27.7 ± 2.05 to - 31.0 ± 1.87 mV, respectively. Entrapment efficiency and assay values ranged from 99.90 ± 0.006 to 99.92 ± 0.002% and 99.3 ± 0.808 to 99.6 ± 0.360, respectively. Physical stability test results revealed that the optimized LNEs were stable for 2 months at both room (25°C) and refrigerated temperature (4°C). The optimized LNE showed 4.32-fold improvement in the oral bioavailability in comparison to a marketed tablet suspension. In vivo anti ulcer activity of rebamipide LNE was studied by testing the prophylactic effect in preventing the mucosal damage in stomach region. The mucosa of stomach in animals was damaged by per oral administration of 80% alcohol. Maximum prophylactic antiulcer activity was observed by per oral delivery of rebamipide as LNE. Our results indicated that LNEs were a promising approach for the oral delivery of rebamipide for systemic effects along with local effects in protecting gastric region, which gets damaged during peptic ulcers.

Preparation of emulsifying wax/glyceryl monooleate nanoparticles and evaluation as a delivery system for repurposing simvastatin in bone regeneration.

Simvastatin (Sim) is a widely known drug in the treatment of hyperlipidemia, which has attracted so much attention in bone regeneration due to its potential osteoanabolic effect. However, repurposing of Sim in bone regeneration will require suitable delivery systems that can negate undesirable off-target/side effects. In this study, we have investigated a new lipid nanoparticle (NP) platform that was fabricated using a binary blend of emulsifying wax (Ewax) and glyceryl monooleate (GMO). Using the binary matrix materials, NPs loaded with Sim (0-500 µg/mL) were prepared and showed an average particle size of about 150 nm. NP size stability was dependent on Sim concentration loaded in NPs. The suitability of NPs prepared with the binary matrix materials in Sim delivery for potential application in bone regeneration was supported by biocompatibility in pre-osteoclastic and pre-osteoblastic cells. Additional data demonstrated that biofunctional Sim was released from NPs that facilitated differentiation of osteoblasts (cells that form bones) while inhibiting differentiation of osteoclasts (cells that resorb bones). The overall work demonstrated the preparation of NPs from Ewax/GMO blends and characterization to ascertain potential suitability in Sim delivery for bone regeneration. Additional studies on osteoblast and osteoclast functions are warranted to fully evaluate the efficacy of Sim-loaded Ewax/GMO NPs using in-vitro and in-vivo approaches.

Preparation and comparison of tacrolimus-loaded solid dispersion and self-microemulsifying drug delivery system by in vitro/in vivo evaluation.

This study aimed to compare the dissolution and the intestinal absorption of tacrolimus in self-microemulsifying drug delivery system (SMEDDS) and solid dispersion (SD). Poloxamer 188 SD was prepared by the combination of the solvent evaporation method and the freeze drying method. Hydroxypropyl methylcellulose (HPMC) SD was prepared by the solvent evaporation method combined with the vacuum drying method. The formation of SD was confirmed by SEM images which showed new solid phases. The SMEDDS was composed of oil (Labrafil M1944 CS 28%), surfactant (Cremophor EL 48%) and co-surfactant (Transcutol P 24%). The self microemulsion formed by the SMEDDS upon aqueous media had spherical droplets with a hydrodynamic size of 46.0±3.2nm. The dissolution of tacrolimus from SD and SMEDDS was performed in sink and non-sink conditions with various pH. As revealed by the DSC and FT-IR, the tacrolimus was molecularly or amorphously dispersed in the SMEDDS and SD. The in vivo intestinal absorption study in rats showed that both SMEDDS and SD improved the absorption of tacrolimus over the raw tacrolimus while the SMEDDS exhibited lower absorption rate constant (Ka) and apparent permeability coefficients (Papp) than the SD. The self-prepared SD with poloxamer 188 or HPMC had comparable intestinal absorption as compared with Prograf®. The tacrolimus-loaded SMEDDS and SD would be further compared by in vivo pharmacokinetic study.

Synthesis and Application of a New Amphiphilic Antioxidant.

A new amphiphilic antioxidant (tannyl stearate) derived from reaction of tannic acid with stearic acid was synthesized in order to improve tannic acid solubility in lipid materials. This reaction gives many products having different degree of esterification (tannyl mono, di, tri, tetra, penta, hexa, hepta……stearate) which were separated using silica gel column chromatography and tentative identification was carried out using thin layer chromatography (TLC). The intrinsic viscosities (η) were used to differentiate between the different molecular weight of the produced esters1). Tannyl penta stearate is assumed to be the most suitable amphiphilic antioxidant derivative, where those derivatives with less degree of esterification would be less soluble in fat, and those of higher degree of esterification would exhaust more hydroxyl group that cause decreases of antioxidant activity. The structure of tannyl penta stearate was approved depending on its chemical analysis and spectral data (IR, H1 NMR,). The emulsification power of tannyl penta stearate was then determined according to method described by El-Sukkary et al.2), in order to prove its amphiphilic property. Then tannyl penta stearate was tested for its antioxidant and radical scavenging activities in three different manners, those are, lipid oxidation in sunflower oil using Rancimat, (DPPH) free radical scavenging and total antioxidant activity. {Pure tannic acid (T), butylhydroxyanisol (BHA) and butylhydroxytoluene (BHT) were used as reference antioxidant radical saving compounds}. Then tannyl penta stearate was added to sunflower oil, frying process was carried out and all physicochemical parameters of the oil were considered, and compared to other reference antioxidant in order to study the effect of this new antioxidant toward oil stability. Acute oral toxicity of the tannyl penta stearate was carried out using albino mice of 21-25 g body weight to determine its safety according to the method described by Goodman et al.3). Also liver and kidney functions of those mice were checked. Thus it could be concluded that the addition of tannyl penta stearate to frying oils offers a good protection against oxidation. The effectiveness of tannyl penta stearate as lipid antioxidant has been attributed mainly to its stability at high temperature. And according to acute lethal toxicity test tannyl penta stearate was found to be a safe compound that can be used as food additive.

Ultrasound Assisted Synthesis of Hydroxylated Soybean Lecithin from Crude Soybean Lecithin as an Emulsifier.

Soybean lecithin is a by-product obtained during degumming step of crude soybean oil refining. Crude soybean lecithin (CSL) contains major amount of phospholipids (PLs) along with minor amount of acylglycerols, bioactive components, etc. Due to presence of PLs, CSL can be used as an emulsifier. Crude soybean lecithin (CSL) was utilized to synthesize hydroxylated soybean lecithin (HSL) by hydroxylation using hydrogen peroxide and catalytic amount of lactic acid to enhance the hydrophilicity and emulsifying properties of CSL. To reduce the reaction time and to increase rate of reaction, HSL was synthesized under ultrasound irradiation. The effect of different operating parameters such as lactic acid, hydrogen peroxide, temperature, ultrasonic power and duty cycle in synthesis of HSL were studied and optimized. The surface tension (SFT), interfacial tension (IFT) and the critical micelle concentration (CMC) of the HSL (26.11 mN/m, 2.67 mN/m, 112 mg/L) were compared to CSL (37.53 mN/m, 6.22 mN/m, 291 mg/L) respectively. The HSL has better emulsion stability and low foaming characteristics as compared to CSL. Therefore, the product as an effective emulsifier can be used in food, pharmacy, lubricant, cosmetics, etc.

The effects of a novel synthetic emulsifier product on growth performance of chickens for fattening and weaned piglets.

Two experiments were conducted to evaluate the effects of a novel synthetic emulsifier product (AVI-MUL TOP) on the growth performance of chickens for fattening and weaned piglets. The emulsifier product consists of 50% vegetal bi-distillated oleic acid emulsified with 50% glyceryl polyethyleneglycol ricinoleate. In experiment 1, 480 1-day-old female Cobb500 chickens for fattening were assigned to two treatments: (1) a control diet (CTR); and (2) the control diet+the emulsifier (AMT, 1 g/kg from day 0 to day 10, 0.75 g/kg from day 10 to day 20 and 0.5 g/kg from day 20 to day 34 of the trial). AMT supplementation increased BW on days 20 and 34 (P<0.01). Dietary AMT increased the average daily gain and average daily feed intake (ADFI) from day 10 to day 20, from day 20 to day 34 and from day 0 to day 34 (P<0.01). A reduced feed conversion ratio was observed in the AMT group from day 10 to day 20 (P<0.01). In experiment 2, 96 Stambo HBI×Dalland piglets were weaned at 24 days and assigned to two treatments (the basal diet without the product (CTR) or with 2 g/kg emulsifier from day 0 to day 14 and 1.5 g/kg from day 14 to day 42 (AMT)). There was an increase in the ADFI associated with AMT supplementation from day 14 to day 42 (P=0.04). These results indicated that supplementation with the synthetic emulsifier may significantly improve the growth performance of chickens for fattening and numerically improve that of weaned piglets.

Rosmarinus officinalis L. extract and some of its active ingredients as potential emulsion stabilizers: a new approach to the formation of multiple (W/O/W) emulsion.

Nowadays, novel topical formulations loaded with natural functional actives are under intense investigations. Therefore, the aim of our study was to evaluate how the rosemary extract and some of its active ingredients [rosmarinic acid (RA), ursolic acid (UA) and oleanolic acid (OA)] affect technological characteristics of multiple emulsion. Formulation has been prepared by adding investigated solutions (10%) in water/oil/water (W/O/W) multiple emulsion consisting of different lipophilic phases: olive oil and liquid paraffin, with 0.5% emulsifying agent (complex of sodium polyacrylate and polysorbate 20) under constant stirring with mechanical stirrer at room temperature. The emulsion parameters were evaluated using centrifugation test, freeze-thaw cycle test, microscopical and texture analyses. Rosemary's triterpenic saponins UA and OA showed the highest emulsion stabilizing properties: they decreased CI from 3.26% to 10.23% (p < 0.05). According to obtained interfacial tension data, the effect of rosemary active ingredients is not surfactant-like. Even though emulsifier itself at low concentration intends to form directly the multiple emulsion, the obtained results indicate that rosemary extract containing active ingredients does not only serve as functional cosmetic agent due to a number of biological activities, but also offer potential advantages as a stabilizer and an enhancer of W/O/W emulsions formation for dermopharmaceutical and cosmetic preparations.

Preparation and performance evaluation of emulsomes as a drug delivery system for silybin.

We developed silybin (SIL) emulsomes and evaluated their physicochemical properties and the in vivo pharmacokinetics of SIL delivered by emulsomes in rats. SIL emulsomes were prepared using the thin film dispersion method. SIL emulsomes were evaluated for their entrapment efficiency, particle size, zeta potential, morphology, in vitro release, and in vivo drug delivery in rats. The entrapment efficiency was above 80 %. The average particle size and zeta potential were 364.1 ± 20 nm and -34 ± 8 mV, respectively. Morphological analysis revealed that the SIL emulsomes were spherical in shape. Compared to an SIL solution, emulsomes produced sustained release of SIL for up to 48 h after an initial burst release in vitro. The pharmacokinetics of SIL emulsomes in rats were evaluated after intravenous injection, and the results were compared with those obtained for the control SIL solution. Following SIL delivery by emulsomes, the area under the curve was 2.2-fold higher and the mean residence time was 2.5-fold higher than the corresponding values recorded using SIL solution. Hence, emulsomes might represent a promising system for improving the bioavailability of lipophilic drugs. Moreover, emulsomes produce sustained drug release, which is advantageous in the clinical setting.

Development and evaluation of glyceryl behenate based solid lipid nanoparticles (SLNs) using hot self-nanoemulsification (SNE) technique.

The purpose of this research was to improve oral bioavailability of poorly aqueous soluble drug lopinavir using solid lipid nanoparticles (SLNs). Glyceryl behenate based SLNs of lopinavir were prepared using hot self-nanoemulsification (SNE) technique. The hot isotropic mixture of glyceryl behenate, Poloxamer 407 and polyethylene glycol 4000 was spontaneously self-nanoemulsify in hot water (80 °C) and SLNs were subsequently formed with rapid cooling. Hot SNE ability of isotropic mixture was visually assessed by ternary phase diagram study. Optimized SLNs were having particle size of 214.5 ± 4.07 nm, entrapment efficiency of 81.6 ± 2.3 % and zeta potential of -12.7 ± 0.87 mV. SLNs were evaluated by transmission electron microscopy and atomic force microscopy for morphological details. Further, differential scanning calorimetry and x-ray diffraction were also performed for solid state characterization of SLNs. Higher oral bioavailability (3.56-fold) was found for lopinavir loaded SLNs in comparison to bulk lopinavir due to higher lymphatic drug transport (p < 0.05). Results indicate that SLNs of glyceryl behenate can be successfully prepared by hot SNE technique.

Development of low-energy methods for preparing food Nano-emulsions.

The aim of this work was to investigate the effect of sucrose on the phase behavior of vegetable oil/polyoxyethylene sorbitan monooleate (MOPS, Tween 80) and decaglycerol monolaurilester (DGML)/aqueous solution systems to establish low-energy emulsification methods for preparing nano-emulsions suitable for food uses. Phase diagrams were constructed to elucidate the optimal process for preparing the nano-emulsions. It was found that nano-emulsions were obtained when the composition was altered to either cross the sponge phase (L(3)) or lamellar phase (La) in the vegetable oil/MOPS/aqueous solution system or vegetable oil/DGML/aqueous solution system, respectively. The average droplet sizes in the former and latter emulsions were 0.203 µm and 0.165 µm, respectively. The addition of sucrose changed the hexagonal phase in the vegetable oil/MOPS/aqueous solution system into the sponge phase. As a result, the sponge region in the vegetable oil/MOPS/sucrose aqueous solution system occupied a larger area than that in the vegetable oil/MOPS/water system. In contrast, sucrose had no effect on the area of the La region in the vegetable oil/DGML/aqueous solution system. However, the addition of sucrose decreased the amount of emulsifier required to prepare nano-emulsions in both the vegetable oil/MOPS and DGML/aqueous solution systems. Sucrose was confirmed to facilitate the preparation of nano-emulsions in both systems.

Preparation and in vitro-in vivo evaluation of Witepsol H35 based self-nanoemulsifying drug delivery systems (SNEDDS) of coenzyme Q(10).

Coenzyme Q(10) (CoQ(10)) was formulated into self-nanoemulsifying drug delivery systems (SNEDDS) to overcome low bioavailability attributed to hydrophobic nature of the drug. Screening of oil phase, surfactants and co-surfactants were performed to select Witepsol H35, Solutol HS15 and Lauroglycol FCC, respectively. Ternary phase diagrams were drawn to identify nanoemulsifying region followed by optimization of SNEDDS formulation. The optimized formulation, CoQ(10), Witepsol H35, Solutol HS15 and Lauroglycol FCC in the weight ratio of 1:0.7:4:2, respectively, emulsified readily at 37 degrees C with mean emulsion droplet size of 32.4 nm. The stability test of the optimized formulation in pH 1.2 and 6.8 buffers confirmed no pH effect on emulsion droplet size. In vitro dissolution (emulsification) test and in vivo animal study of the formulation elucidated the complete emulsification of drug and improved oral bioavailability of poorly soluble CoQ(10).

Solid self-emulsifying nitrendipine pellets: preparation and in vitro/in vivo evaluation.

Objective of this study is to develop and evaluate the new solid self-emulsifying (SE) pellets of poorly soluble nitrendipine (NTD). These pellets were prepared via extrusion/spheronization technique, using liquid SEDDS (NTD, Miglyol 812, Cremophor RH 40, Tween 80, and Transcutol P), adsorbents (silicon dioxide and crospovidone), microcrystalline cellulose and lactose. The resulting SE pellets with 30% liquid SEDDS exhibited uniform size (800-1000 microm) and round shape, droplet size distribution following self-emulsification was nearly same to the liquid SEDDS (72+/-16 nm and 64+/-12 nm). The in vitro release was similar for the two SE formulations (over 80% within 30 min), both significantly higher than the conventional tablets (only 35% within 30 min). The oral bioavailability was evaluated for the SE pellets, liquid SEDDS and conventional tablets in fasted beagle dogs. AUC of NTD from the SE pellets showed 1.6-fold greater than the conventional tablets and no significant difference compared with the liquid SEDDS. In conclusion, our studies illustrated that extrusion/spheronization technique could be a useful large-scale producing method to prepare the solid SE pellets from liquid SEDDS, which can improve oral absorption of NTD, nearly equivalent to the liquid SEDDS, but better in the formulation stability, drugs leakage and precipitation, etc.

Study of the preparation of sustained-release microspheres containing zedoary turmeric oil by the emulsion-solvent-diffusion method and evaluation of the self-emulsification and bioavailability of the oil.

The purpose of this study was to design a sustained-release formulation of an oily drug. The sustained-release microspheres with self-emulsifying capability containing zedoary turmeric oil (ZTO) were prepared by the quasi-emulsion-solvent-diffusion method. The micromeritic properties, the efficiency of emulsification and the drug-release behavior of the resultant microspheres were investigated. The bioavailability of the microspheres was compared with conventional ZTO self-emulsifying formulations for oral administration using 12 healthy rabbits. An HPLC method was employed to determine the concentration of germacrone in plasma, which was used as an index of ZTO. Spherical and compacted microspheres with average diameters of 100-600 microm have been prepared, and their release behavior in distilled water containing 1.2% (w/v) of polysorbate-80 can be controlled by the ratio of polymer/Areosil200 in the microspheres. The resultant emulsions with mean droplet sizes of 200-500 nm are produced when the microspheres are immersed in phosphate buffer (pH 6.8) under gentle agitation. The stability and the droplet size of the resultant emulsions are also affected by the polymer/Areosil200 ratio in the formulation, while the amount of talc has a marked effect on the self-emulsifying rate. The plasma concentration-time profiles with improved sustained-release characteristics were achieved after oral administration of the microspheres with a bioavailability of 135.6% with respect to the conventional self-emulsifying formulation (a good strategy for improving the bioavailability of an oily drug). In conclusion, the sustained-release microspheres with self-emulsifying capability containing ZTO have an improved oral bioavailability. Our study offers an alternative method for designing sustained-release preparations of oily drugs.

Optimization of distilled monoglycerides production.

Monoglycerides (MG) are emulsifiers widely used in food and pharmaceutical industries. Current industrial processes for MG production consist of the interesterification of triglycerides with glycerol (GL), in the presence of inorganic catalysts at high temperatures (>200 degrees C). This reaction is known as glycerolysis and produces a mixture of approx 50% of MG. This level of concentration is suitable for many applications, although, for some specific uses like margarine, shortening, icing, and cream filling, require distilled MGs, which are purified MG (min. 90%) obtained by the molecular distillation process. Therefore, in this work, a 2(3) factorial design was employed to evaluate the effects of reaction parameters in the MG content after the interesterification reaction of refined soybean oil with GL in the presence of sodium hydroxide as catalyst. After that, the MG content in the reaction product was enhanced through the molecular distillation process in order to obtain distilled MG.

A novel formulation design about water-insoluble oily drug: preparation of zedoary turmeric oil microspheres with self-emulsifying ability and evaluation in rabbits.

To enhance in vivo absorption of zedoary turmeric oil (ZTO) and develop new formulations of a water-insoluble oily drug, novel ZTO microspheres with self-emulsifying ability, called self-emulsifying microspheres here, were prepared in a liquid system by the quasi-emulsion solvent diffusion method. The microspheres containing hydroxypropyl methylcellulose acetate succinate (HPMCAS-LG), Talc and Aerosil 200 formed the stable surfactant-free emulsion when exposed to the pH 6.8 phosphate buffer, and were significantly different from the conventional self-emulsifying systems (SES), defined as isotropic mixtures of oil, surfactant and drug. Micromeritic properties, the efficiency of emulsification and the drug-release rate of the resultant microspheres were investigated. The bioavailability of the microspheres to the conventional self-emulsifying formulation for oral administration was evaluated in 12 healthy rabbits. A HPLC method was employed to determine the plasma concentration of Germacrone, an indexical component found in ZTO. The release rates of ZTO and Germacrone from the microspheres were enhanced significantly with increasing amounts of dispersing agents, and the efficiency of self-emulsification greatly depended on the HPMCAS-LG/Aerosil 200 ratio. The emulsion droplets released from the microspheres were much smaller than that of the conventional SES. The microsphere bioavailability (F) to the conventional SES for oral administration was 157.7%. Our method greatly improved the bioavailability of the water-insoluble oily drug from the self-emulsifying microspheres over the conventional SES and it is useful for the oily drug to form solid preparations.