Deep Eutectic Solvents Based on Carboxylic Acids and Glycerol or Propylene Glycol as Green Media for Extraction of Bioactive Substances from Chamaenerion angustifolium (L.) Scop.

Chamaenerion angustifolium (L.) Scop. is one of the promising sources of biologically active compounds and a valuable industrial crop. Recently, green extraction methods have become more topical. One of them is the application of deep eutectic solvents (DESs). The aim of this work was the synthesis and characterization of DES consisting of glycerin or propylene glycol with malonic, malic, or citric acids, evaluation of their effectiveness for extracting useful substances from C. angustifolium during ultrasonic extraction, description of kinetics, and optimization of extraction conditions. DESs were obtained and characterized with FTIR. Their effectiveness in the process of ultrasound-assisted extraction of biologically active substances from C. angustifolium was estimated. Kinetic parameters describing the dependence of the total phenolic, flavonoids, and antioxidant content, free radical scavenging of DPPH, and concentration of flavonoid aglycons (myricetin, quercetin, and kaempferol) via time in the range of 5-60 min at 45 °C are obtained. Extraction conditions were optimized with the Box-Behnken design of experiment. The results of this work make it possible to expand the scope of DES applications and serve the development of C. angustifolium processing methods.

Effects of microfluidization and thermal treatment on the characterization and digestion of curcumin loaded protein-polysaccharide-tea saponin complex nanoparticles.

Microfluidization (50-150 MPa) and thermal treatment (45-85 °C) were applied to modulate the physicochemical stability, molecular interaction and microstructure of zein-proplyene glycol alginate (PGA)-tea saponin (TS) complex nanoparticles for delivery of curcumin. The size of these complex nanoparticles was decreased from 583.1 to 267.4 nm as the microfluidization pressure was increased from 0 to 100 MPa. In the combined treatment of microfluidization and heating, 100 MPa and 75 °C were the optimum parameters to prepare zein-PGA-TS complex nanoparticles for a better protection of curcumin against various environmental stresses. SEM revealed a synergistic effect of microfluidization and heating on the fabrication of complex nanoparticles with a more uniform size and spherical shape. During in vitro gastrointestinal digestion, the complex nanoparticles showed an excellent gastric stability and a sustained release of curcumin in the small intestinal phase. These findings interpreted the effects of microfluidization and thermal treatment on the functional properties of protein-polysaccharide-surfactant complex nanoparticles that can be utilized to develop food grade nanoparticles with enhanced stability and controllable digestion behaviour.

Interesterification of Soybean Oil with Propylene Glycol in Supercritical Carbon Dioxide and Analysis by NMR Spectroscopy.

The time course study of high monoester mixtures from soybean oil (HMMS) synthesis, as healthier alternatives to trans food products, in a supercritical CO2 (SCCO2) medium with and without enzyme, was investigated. Phosphorous nuclear magnetic resonance (31P-NMR) was used to quantify the absolute amount of partially esterified acylglycerols (PEGs). Carbon NMR was utilized to determine the type and position of the fatty acids (FAs) of HMMS. Enzyme and time significantly influenced the synthesis of 1-monoglycerides (1-MGs), 2-MGs, and 1,2-diglycerides (1,2-DGs) in this alcoholysis of soybean oil with 1,2-propanediol, based on high catalytic activity and operational stability of Novozym 435 in SCCO2 during short reaction time. Results suggest that 4 h is a suitable reaction time for this lipase-catalyzed interesterification (LIE) system for the synthesis of 2-MGs with a yield of 20%. The highest polyunsaturated fatty acid (PUFA) (65%) in the triglyceride (TG) of HMMS was produced after 4 h of reaction. After 6 h of reaction, a high level (20%) of saturated fatty acids (SFAs) was found in the TGs of HMMS, which were distributed between the sn-2 (5%) and sn-1, 3 (15%) positions.

In situ microemulsion-gel obtained from bioadhesive hydroxypropyl methylcellulose films for transdermal administration of zidovudine.

This study aims to develop in situ microemulsion-gel (ME-Gel) obtained from hydroxypropyl methylcellulose (HPMC) films for transdermal administration of Zidovudine (AZT). Firstly, HPMC films containing propylene glycol (PG) and eucalyptus oil (EO) were obtained and characterized. Later, a pseudo-ternary phase diagram composed of water, EO, tween 80 and PG was obtained and one microemulsion (ME) with a similar proportion of the film components was obtained. ME was transformed in ME-Gel by the incorporation of HPMC. Finally, HPMC films were hydrated with Tween 80 solution to yield in situ ME-Gel and its effect on AZT skin permeation was compared with HPMC film hydrated with water (F5hyd). The results showed that the ME and ME-Gel presented a droplet size of 16.79 and 122.13 µm, respectively, polydispersity index (PDI) < 0.39 and pH between 5.10 and 5.40. The incorporation of HPMC resulted in viscosity about 2 times higher than the use of ME. The presence of AZT did not alter the formulation properties. The in situ ME-Gel promoted a two-fold increase in the permeated amount of AZT compared to F5hyd. The results suggest that it was possible to obtain an ME-Gel in situ from HPMC films and that its effect on transdermal permeation of AZT was significant.

Techno-biofunctionality of mangostin extract-loaded virgin coconut oil nanoemulsion and nanoemulgel.

Techno-biofunctional characteristics of nanoemulsion and (nano)emulgel loaded with mangostin extracts were elucidated. Crude mangostins from mangosteen peels recovered by virgin coconut oil (VCO), mixed VCO and propylene glycol (PG), and pure PG were used. The extracts were loaded in the dispersed phase in the presence of mixed surfactants (Tween20/Span20) with a varying hydrophilic-lipophilic balance (HLB) from 10.2 to 15.1. Results showed that globular and uniformly distributed droplets of the nanoemulsion were observed. The small particle sizes (typically 18-62 nm) with the zeta potential of -39 to -54.5 mV were obtained when mixed emulsifiers with HLB values of 12.6 and 15.1 were employed. With HLB values of 12.6 and 15.1, nanoemulsions loaded with mangostin extracts prepared with mixed VCO-PG and pure PG-based extracts showed approximately a 2 to 3-fold lower droplet size diameter when compared with the VCO-based extract. For the stability test, all nanoemulsions were stable over three freeze-thaw cycles with some changes in pH, zeta potential, and droplet size. The DPPH● scavenging activity, H2O2 scavenging activity, reducing power and antibacterial activities (E. coli and S. aureus) of the nanoemulsions were greater than their corresponding bulk extracts. Nanoemulgels produced by embedding the nanoemulsions in a hydrogel matrix was homogeneous and creamy yellow-white in appearance. The nanoemulgels had a higher mangostin release (87-92%) than their normal emulgels (74-78%). Therefore, this study presented the feasibility of nanoemulsions and nanoemulgels loaded with mangostin extracts as a promising delivery system for bioactive polyphenol in food supplements, pharmaceuticals and cosmetics.

Phosphorus-Containing Flame Retardants from Biobased Chemicals and Their Application in Polyesters and Epoxy Resins.

Phosphorus-containing flame retardants synthesized from renewable resources have had a lot of impact in recent years. This article outlines the synthesis, characterization and evaluation of these compounds in polyesters and epoxy resins. The different approaches used in producing biobased flame retardant polyesters and epoxy resins are reported. While for the polyesters biomass derived compounds usually are phosphorylated and melt blended with the polymer, biobased flame retardants for epoxy resins are directly incorporated into the polymer structure by a using a phosphorylated biobased monomer or curing agent. Evaluating the efficiency of the flame retardant composites is done by discussing results obtained from UL94 vertical burning, limiting oxygen index (LOI) and cone calorimetry tests. The review ends with an outlook on future development trends of biobased flame retardant systems for polyesters and epoxy resins.

Natural deep eutectic solvents and aqueous solutions as an alternative extraction media for propolis.

Ethanolic extracts of propolis are consumed for their health benefits even though direct consumption of alcoholic extracts is not always ideal. Natural Deep Eutectic Solvents (NADES) can potentially extract similar compounds as alcoholic extracts while being better for direct consumption. Therefore, in this work alternative solvents for the extraction of green propolis including its biomarker artepillin C were examined. Sixteen NADES made from low toxicity chemicals, including the essential amino acid l-lysine, were explored along with twelve individual NADES components and honey, which showed similar physical-chemical properties to NADES. At 50 °C NADES made from choline chloride-propylene glycol or lactic acid proved to be equal or better than the benchmark EtOH:Water 7:3 (v/v). Alternatively, aqueous l-lysine appeared as a potential solvent for the preparation of aqueous propolis extracts. From these findings NADES, honey and aqueous l-lysine solutions all demonstrated the potential to replace ethanol or water for extracting green propolis.

Transdermal fennel essential oil nanoemulsions with promising hepatic dysfunction healing effect: in vitro and in vivo study.

Fennel (Foeniculum vulgare Mill.) is a member of family Apiaceae. Trans-anethole, the major component of Fennel essential oil (FEO), possesses antioxidant and hepatoprotective effects. Transdermal nanoemulsions (NEs) are advanced colloidal systems for systemic and controlled drug delivery through the stratum corneum barrier. FEO NEs were prepared using the oil Lauroglycol™ 90, as it provides a larger NE existence zone than Captex® 300, in the constructed phase diagrams. Six systems were prepared using Tween20/propylene glycol (S/CoS) in the ratios 2:1 and 3:1 with oil to S/CoS mass ratios 1:9, 2:8 and 3:7. Physicochemical characterization revealed optimum properties regarding thermodynamic stability, droplet size and pH with a Newtonian flow pattern. In vitro permeation study in rat skin revealed the highest cumulative amount permeated (µg/cm2), flux and permeability coefficient values for F4 made up of 2% FEO, 4.67% Lauroglycol™ 90, 60% S/CoS in the ratio 3:1. Results of the in vivo hepatic dysfunction study in rats indicate promising significant amelioration of liver function reflected in ALT, AST, ALP, bilirubin, albumin, malondialdehyde and ammonia plasma levels. The results signify the promising approach of FEO NEs in achieving remedy of liver toxicity. The most promising effect is inherent to F4 which imparts a more positive effect than FEO.

Polyalcohols as Hydrogen-Bonding Donors in Choline Chloride-Based Deep Eutectic Solvents for Extraction of Xanthones from the Pericarp of Garcinia mangostana L.

Mangosteen (Garcinia mangostana L.) is a fruit that is rich in xanthones, utilized as health supplements or additives in food products due to their high antioxidant activities. Choline chloride (ChCl)-based deep eutectic solvents (DESs) with polyalcohols (ethylene glycol, glycerol, propanediols, and butanediols) as hydrogen bonding donors (HBDs) were used to extract the xanthones from the pericarp of mangosteen. DESs with 1,2-propanediol, 1,3-propanediol, and 1,2-butanediol as HBDs (ChCl to HBD mole ratio of 1:3) afforded the highest extraction yields (2.40-2.63%) of α-mangostin, the most abundant component that represents xanthones. These DESs have intermediate Nile Red polar parameter values similar to that of ethanol and provide extraction yields with a quadratic dependence on the polar parameter. Polarity and viscosity, the important physicochemical properties to consider in the selection of DES as an extraction solvent, could be adjusted based on the consideration of the molecular structure of the polyalcohols. The following factors qualifies the ChCl-1,2-propanediol DES as a designer solvent for green extraction: It is selected from a set of DESs having a homologous class of HBDs to deliver the highest α-mangostin extraction yield, its extract composition similar to that obtained using ethanol, it has low or negligible vapor pressure, both of its components are generally recognized as safe chemicals so that direct utilization of a DES extract is possible, and this DES is used for utilization of agricultural waste products as the resource of bioactive compounds.

Azithromycin-loaded liposomes for enhanced topical treatment of methicillin-resistant Staphyloccocus aureus (MRSA) infections.

Antibiotic delivery via liposomal encapsulation represents a promising approach for the efficient topical treatment of skin infections. The present study aimed to investigate the potential of using different types of azithromycin (AZT)-loaded liposomes to locally treat skin infections caused by methicillin-resistant Staphylococcus aureus (MRSA) strains. Conventional liposomes (CLs), deformable liposomes (DLs), propylene glycol-containing liposomes (PGLs) and cationic liposomes (CATLs) encapsulating AZT were prepared, and their physical characteristics, drug release profiles, ex vivo skin penetration/deposition abilities, in vitro anti-MRSA activities (planktonic bacteria and biofilm) and cell biocompatibilities were assessed. The (phospho)lipid composition and presence of surfactant or propylene glycol affected the physical characteristics of the liposomes, the release profile of AZT, its deposition inside the skin, as well as in vitro antibacterial efficacy and tolerability with the skin cells. All the liposomes retained AZT inside the skin more efficiently than did the control and were biocompatible with keratinocytes and fibroblasts. CATLs, DLs and PGLs efficiently inhibited MRSA strain growth and were superior to free AZT in preventing biofilm formation, exhibiting minimal inhibitory concentrations and minimal biofilm inhibitory concentrations up to 32-fold lower than those of AZT solution, thus confirming their potential for improved topical treatment of MRSA-caused skin infections.

Preparation of Curcuma comosa tablets using liquisolid techniques: In vitro and in vivo evaluation.

Curcuma comosa (C. comosa) is a Thai medicinal herb that provides numerous pharmacologic activities due to its estrogen-like action. This study aimed to investigate the use of liquisolid technique to prepare tablets containing oleoresin-like crude extract of C. comosa, and to improve the dissolution profiles of its major compounds, diarylheptanoids (DAs). Free flowing powders of C. comosa extract were obtained by adsorption onto solid carriers, microcrystalline cellulose, with colloidal silica as coating material. FTIR results ruled out possible interactions between C. comosa extract and excipients. The results indicated that all of liquisolid tablets met the USP requirements. The release of DAs were significantly increased through liquisolid formulations, compared to crude extract. By decreasing the ratio of carrier to coating from 20 to 10, an improvement in dissolution rate was observed. Addition of additives - namely polymer (polyvinyl pyrrolidone) and/or nonvolatile liquid (propylene glycol) affected tablet properties which involved longer disintegration time and lower DA dissolution. Optimized C. comosa liquisolid formulation was prepared in a carrier to coating ratio of 10 without additives. Stability studies showed that physical properties of liquisolid tablet were not affected by aging, but percent remaining and dissolution profiles of DAs were influenced by storage temperature. In vivo pharmacokinetic behavior of the optimized C. comosa liquisolid tablets was investigated following a single oral administration to rabbits. The results proved that the method used for preparation of liquisolid led to C. comosa tablets with low variation in content uniformity and tablet properties, as well as enhanced dissolution behavior.

Microemulsions based on TPGS and isostearic acid for imiquimod formulation and skin delivery.

Imiquimod (IMQ) is an immunostimulant drug topically used for the treatment of actinic keratosis and basal cell carcinoma. IMQ formulation and skin delivery is difficult because of its very low solubility in the most of pharmaceutical excipients and very poor skin penetration properties. The purpose of this study was to develop a microemulsion to optimize imiquimod skin delivery using d­α­tocopherol polyethylene glycol-1000 succinate (TPGS) as surfactant (so as to take advantage of its thickening properties) and isostearic acid as oil phase. This fatty acid was selected since it has demonstrated a good solubilizing power for imiquimod and it has also shown to contribute to its therapeutic activity. We have built pseudo-ternary diagrams using two different co-surfactants (Transcutol® and propylene glycol - PG) in a 1:1 ratio with TPGS and then selected microemulsions in the clear and viscous regions of the diagrams. The systems were characterized in terms of rheology and X-ray scattering; additionally, the capability to promote IMQ skin uptake was evaluated ex-vivo on a porcine skin model. All the formulations selected in the gel-microemulsion regions behaved as viscoelastic solids; X-rays scattering experiments revealed in all cases the presence of an ordered lamellar structure, but with differences in terms of interlamellar distance and flexibility between Transcutol® and PG-containing systems. A higher flexibility and a greater hydrophobic volume, possibly interconnected at some point, was associated to the use of Transcutol® and had an impact on the microemulsion capacity to solubilize IMQ as well as on the capability to enhance drug uptake into the skin. The best performing gel-like microemulsion was composed of ≈26% of water, ≈21% of isostearic acid, ≈26% of TPGS and ≈27% of Transcutol® and accumulated, after 6 h of contact, 3.0 ±â€¯1.1 µg/cm2 of IMQ. This value is higher than the one reported in the literature for the commercial cream (1.9 ±â€¯0.8 µg/cm2), despite the 4-times lower concentration of the vehicle (13 mg/g for the microemulsion vs 50 mg/g for the commercial cream).

Green and efficient extraction of four bioactive flavonoids from Pollen Typhae by ultrasound-assisted deep eutectic solvents extraction.

Recently, deep eutectic solvents (DESs) have been recognized as a novel class of sustainable solvents to replace common organic solvents. In this study, a highly and efficient extraction technique for determination of four bioactive flavonoids from Pollen Typhae using a combination of ultrasound-assisted extraction and natural deep eutectic solvents (NADESs) was developed. A series of DESs containing various hydrogen bond acceptors combined with different hydrogen bond donors were synthesized and screened for high extraction efficiencies based on the flavonoids extraction yields. The extraction conditions including composition of DES, water content in DES, liquid-solid ratio, and extraction time were statistically optimized by single-factor experiment. As a result, DES composed of choline chloride and 1,2-propanediol (ChPri) at 1:4 M ratio, 30% of aqueous solution, 50:1 mg mL-1 for solid-liquid ratio, and 35 min for extraction time were selected as the most effective process for extraction of flavonoids in Pollen Typhae. Under the optimal conditions, the target compounds recoveries were in the range of 86.87%-98.89%. Meanwhile, DESs showed greater extraction efficiency for extraction of quercetin, naringenin, kaempferol and isorhamnetin from Pollen Typhae comparing with conventional solvents such as methanol and 75% of aqueous ethanol. Comparing DESs to the conventional organic solvents, in addition to their reduced environmental impacts, they proved to provide higher extraction efficiency for flavonoids, and therefore have a great potential as possible alternatives to those organic solvents in extraction of Chinese herbal medicines.

Formulation Development and Evaluation of Diphenhydramine Nasal Nano-Emulgel.

The aim of present study is to formulate diphenhydramine nasal nano-emulgels, having lipophilic nano-sized interior droplets, with better penetration for targeted controlled delivery to mucous membrane. Different diphenhydramine (DPH) nasal nano-emulgels were developed having propylene glycol and olive oil (as permeation enhancers) by using RSM for optimization and then evaluated for physico-chemical characteristics and thermal stability. In-vitro drug release through cellophane membrane was conducted and results were analyzed statistically. Further, gelation, mucoadhesive stress, and ex-vivo and histopathological studies were performed on optimized formulation by using goat nasal membrane. Among all formulations, E2 showed maximum DPH release at higher concentration olive oil (4%) and lower concentration propylene glycol (PG) (25%) within 4 h. All formulations have followed first-order kinetics and drug release mechanism was Fickian diffusion. Analysis of variance (ANOVA) and multiple linear regression analysis (MLRA) were used to compare results among formulations and 3D surface plots were constructed also. Optimized formulation showed immediate prolong gelation in artificial nasal mucosa and excellent mucoadhesive property (72.5 ± 1.5 dynes/cm2). Approximately 97.1% optimized formulation was permeated through membrane within 4 h, having a high flux rate (33.19 ± 0.897 µg/cm2/min) with diffusion coefficient (0.000786 ± 4.56 × 10-5 cm2/min) while drug contents remained on mucosal membrane for 24 h. Histopathologically, change on intra-mucosal surface of excised membrane was observed due to passage of drug through it. In summary, combination of PG and olive oil in nasal DPH nano-emulgel can be utilized successfully for targeted controlled delivery. The optimized formulation has excellent permeability and prolonged residence time on mucosal surface, which prove its good anti-histaminic activity in case of allergic rhinitis.

Effect of Alcohols on the Phase Behavior and Emulsification of a Sucrose Fatty Acid Ester/Water/Edible Oil System.

The effect of alcohols (ethanol, 1-propanol, propylene glycol, glycerin, sucrose) on the phase behavior and emulsification of sucrose stearic acid ester (SSE)/water/edible vegetable oil (EVO) systems was investigated. Adding sucrose, propylene glycol, and glycerin narrowed the oil-separated two-phase region in the phase diagram of the SSE/water/EVO systems, whereas adding ethanol and 1-propanol expanded the oil-separated two-phase region. Changing the course of emulsification in the phase diagram showed that the size of the oil-droplet particle typically decreased in a system with a narrowed oil-separated region. The emulsification properties of the systems varied with respect to changes in the phase diagram. The microstructure of the systems was examined using small-angle X-ray scattering, and the ability to retain the oil in the lamellar structure of the SSEs was suggested as an important role in emulsification, because the mechanism of the systems was the same as that for the liquid crystal emulsification method.

Deep Eutectic Solvent-Based Microwave-Assisted Method for Extraction of Hydrophilic and Hydrophobic Components from Radix Salviae miltiorrhizae.

Deep eutectic solvents (DESs) have attracted significant attention as a promising green media. In this work, twenty-five kinds of benign choline chloride-based DESs with microwave-assisted methods were applied to quickly extract active components from Radix Salviae miltiorrhizae. The extraction factors, including temperature, time, power of microwave, and solid/liquid ratio, were investigated systematically by response surface methodology. The hydrophilic and hydrophobic ingredients were extracted simultaneously under the optimized conditions: 20 vol% of water in choline chloride/1,2-propanediol (1:1, molar ratio) as solvent, microwave power of 800 W, temperature at 70 °C, time at 11.11 min, and solid/liquid ratio of 0.007 g·mL-1. The extraction yield was comparable to, or even better than, conventional methods with organic solvents. The microstructure alteration of samples before and after extraction was also investigated. The method validation was tested as the linearity of analytes (r² > 0.9997 over two orders of magnitude), precision (intra-day relative standard deviation (RSD) < 2.49 and inter-day RSD < 2.96), and accuracy (recoveries ranging from 95.04% to 99.93%). The proposed DESs combined with the microwave-assisted method provided a prominent advantage for fast and efficient extraction of active components, and DESs could be extended as solvents to extract and analyze complex environmental and pharmaceutical samples.

A novel intravenous vehicle for preclinical cardiovascular screening of small molecule drug candidates in rat.

Screening novel, poorly soluble small-molecule candidates for cardiovascular liabilities represents a key challenge in early drug discovery. This report describes a novel vehicle composed of 20% N,N-Dimethylacetamide (DMA)/40% Propylene glycol (PG)/40% Polyethylene Glycol (PEG-400) (DPP) for administration of new chemical entities (NCEs) by slow intravenous (i.v.) infusion in a preclinical anesthetized rat model. The vehicle was designed considering both available excipient safety information and solubilization potential for poorly soluble NCEs. DPP solubilized 11 drugs, 8 of which were insoluble in 5% dextrose in water (D5W), and 5 insoluble in PEG-400 to a target concentration of 30mg/mL. DPP elicits no adverse cardiovascular responses in the anesthetized rat model despite containing 40% PEG-400, a commonly used organic solvent which elicits hypertension and bradycardia that often confounds interpretation of drug effects. Three compounds demonstrating adequate solubility in both DPP and D5W were screened in the anesthetized rat model. When normalized to plasma exposure, atenolol, sotalol and enalaprilat exhibited comparable mean arterial pressure, heart rate, and cardiac contractility responses regardless of formulation. While the antihypertensive effect of nifedipine was evident with both DPP and PEG-400 formulations, pressor effects from PEG-400 confounded interpretation of the magnitude of nifedipine's response. Plasma concentrations of atenolol and enalaprilat were greater in D5W formulation whereas sotalol exposures were greater when using DPP as a vehicle. These results demonstrate the utility of DPP as an intravenous vehicle for formulating poorly soluble compounds in early preclinical screening for cardiovascular safety studies.

Pluronic lecithin organogel (PLO) of diltiazem hydrochloride: effect of solvents/penetration enhancers on ex vivo permeation.

In the present study, pluronic lecithin organogel (PLO) of diltiazem hydrochloride (DZH) was developed by taking different ratios of organic phase to aqueous phase (1:3, 1:4, and 1:5) with varying concentration of soya lecithin (20, 30, and 40 % w/w) in organic phase (isopropyl myristate, IPM) and pluronic (20, 25, and 30 % w/w) in aqueous phase, respectively, and characterized for in vitro parameters and ex vivo permeation study. The results of in vitro parameters were found to be within permissible limit and all the PLOs were physically stable at refrigeration and ambient temperature. The influence of phase ratio and different concentrations of soya lecithin on DZH release from the PLOs was found to be significant (p < 0.05), whereas the influences of different concentrations of pluronic were insignificant. The effect of different solvents/penetration enhancers viz. IPM, propylene glycol (PG), dimethyl sulphoxide (DMSO), and D-limonene, in combination and alone, on the permeation of DZH across the dorsal skin of rat was studied. Among all, formulation containing IPM (PLO6) exhibited highest flux of 147.317 µg/cm(2)/h. Furthermore, histopathology section of treated skin sample illustrated that lipid bilayer disruption was the mechanism for the DZH permeation. The above results indicated that PLO6 may serve as a promising alternative delivery system for DZH in the effective treatment of hypertension.

Oil-based compositions as saliva substitutes: A pilot study to investigate in-mouth retention.

OBJECTIVES: This pilot study aimed to compare the in-mouth retention of an oil-based saliva substitute (emulsion, consisting of rice bran oil, soy lecithin and water) with water and a 1% w/v methylcellulose suspension (polymer) in healthy volunteers. METHODS: Each formulation was tagged with 1 mmol/L lithium and participants (n=30) rinsed their mouth with one randomly assigned formulation (emulsion, polymer or water) for 30s, before expectorating into a cup. Concentration of lithium expectorated was measured and amount of each formulation remaining in the mouth was estimated. Patient acceptability was investigated using questionnaires, and Fourier-Transform Infrared spectroscopy (FTIR) was used to determine the presence of oil in expectorated samples. RESULTS: Immediately after rinsing, taste was rated lower in the emulsion group compared to the polymer or water groups (p>0.05), although variability was high. Mean retention was highest in the emulsion group, with a difference of 8.34 ± 2.71% (p=0.003) and 4.57 ± 2.71% (p=0.06) compared with the water and polymer groups, respectively. FTIR confirmed the presence of oil in all expectorated emulsion samples. CONCLUSION: The emulsion was not inferior to the polymer in terms of retention immediately after rinsing. The next step is to conduct larger clinical studies over longer time periods in participants with salivary hypofunction.

Formation of microemulsions for using as cosmeceutical delivery systems: effects of various components and characteristics of some formulations.

Microemulsions are interesting formulations for cosmeceutical applications due to their good appearance, high solubilization power, thermodynamic stability, and enhancement of skin penetration. In addition, they can spontaneously form when suitable types and amounts of components are simply mixed. In this study, the phase behavior of the nonionic systems with various parameters was studied by construction of phase diagrams using titration method. Natural oils, i.e., coconut oil (CO), rice bran oil (RBO), and palm oil (PO), were analyzed for their fatty acid compositions and then mixed with blends of nonionic surfactants (Tween80: Span80) and water or mixtures of water and a cosolvent, propylene glycol (PG), to find the microemulsion regions. Subsequently, some microemulsions were selected for physical characterization. The largest microemulsion regions which were obtained from CO, RBO, and PO covered the sizes of 11.65, 9.84, and 9.24 %, respectively. The surfactant mixture at weight ratio of 1:1 was the most suitable for CO and PO, but for RBO, it was 2:1. PG could increase the microemulsion regions of PO from 9.24 to 15.33 %, depending on PG concentrations. Hence, the sizes of the microemulsion regions were related to oil types, surfactant mixtures, and ratios between water and PG. The studied microemulsions were water-in-oil (w/o) type, and their internal droplets were in the nanosize range. They exhibited Newtonian flow behavior and their mean viscosity values were from 247.53 to 690.35 cP which were correlated with the types and concentrations of the components in the formulations. In conclusion, natural oils could form w/o microemulsions with nonionic surfactants. The microemulsion formation and characteristics were related to many parameters of the components.