Pickering emulsion-enhanced Vibrio fischeri assay for ecotoxicity assessment of highly hydrophobic polycyclic aromatic hydrocarbons.

Accurate ecotoxicity assessment of contaminated soil is critical to public health, and the luminescent bacteria (Vibrio fischeri) method is the most commonly used. Hydrophobic compounds such as polycyclic aromatic hydrocarbons (PAHs) in soil cannot be in contact with luminescent bacteria due to their low water solubility so that the luminescence inhibitory effect cannot be observed. The underestimated biological toxicity makes the test unreliable and en-dangers public health and safety. The commonly adopted improved method of adding cosolvents has limited effect, it was only effective for low-hydrophobicity chemicals and could not be used for ecotoxicity evaluation of high-hydrophobicity chemicals. Therefore, we constructed Pickering emulsions using luminescent bacteria modified with n-dodecanol in which PAHs were dissolved in the oil phase, n-tetradecane. Then the luminescent bacteria could tightly adhere to the oil-water interface and contact PAHs. As a result, their bioluminescence was suppressed to varying degrees depending on the chemical species and concentrations. With no solubility limitation, highly hydrophobic PAHs could even completely inhibit bacterial bioluminescence, hence the toxicity information was accurately displayed and the median effect concentration (EC50) values could be calculated. This Pickering emulsion-based method was successfully applied for the accurate ecotoxicity evaluation of highly hydrophobic PAHs and soil samples contaminated with them, which all previous methods could not achieve. This method overcomes the problem of ecotoxicity evaluation of hydrophobic compounds, and has great potential for practical application, whether it is pure chemicals or various real samples from the ecological environment.

Synthesis, characterization and toxicity assessment of a new polymeric nanoparticle, l-glutamic acid-g-p(HEMA).

The toxic effects of poly(HEMA)-based polymeric nanoparticles must be analyzed before their biomedical applications as drug delivery systems. The aim of the study was to characterize and evaluate the toxicity for its biocompatibility of a newly synthesized l-glutamic acid-g-p(HEMA) polymeric nanoparticle The nanoparticle was synthesized with surfactant-free emulsion polymerization and grafting techniques. Grafting efficiency was estimated at 58%. The nanoparticle shape was verified as nearly spherical by scanning electron microscopy. Atomic force microscopy images showed a rough surface topography. The nanoparticle had an average size of ~194.6 nm on zeta analysis, and the zeta potential value was -18 mV. Fourier transformed infrared spectroscopy revealed spectra from 750 to 4000 cm-1 and characteristic peaks of stretching bands. The swelling ratio was 46%. With 24-h exposure, p(HEMA) and l-glutamic acid-g-p(HEMA) did not have cytotoxic effects on a human bronchial epithelial cell line (16HBE) and human monocyte cell line by water-soluble tetrazolium salt 1 (WST-1) assay and lactate dehydrogenase assay (LDH). It did not show genotoxic potential by comet assay and did not have mutagenic effects on Salmonella typhimurium TA98, TA100, TA1535 and TA1537 strains by Ames test. The nanoparticle at 160 µg/ml showed 2% hemolytic activity on erythrocytes. On cell migration assay, the percentage closure difference between exposed and control cells was estimated at 21%. We found no irritation effect on Hen's egg test-chorioallantoic membrane test. We determined that the polymeric nanoparticle l-glutamic acid-g-p(HEMA) was biocompatible and has potential for use in a drug delivery system.

Impact of various solid carriers and spray drying on pre/post compression properties of solid SNEDDS loaded with glimepiride: in vitro-ex vivo evaluation and cytotoxicity assessment.

Development of self-nanoemulsifying drug delivery systems (SNEDDS) of glimepiride is reported with the aim to achieve its oral delivery. Lauroglycol FCC, Tween-80, and ethanol were used as oil, surfactant, and co-surfactant, respectively as independent variables. The optimized composition of SNEDDS formulation (F1) was 10% v/v Lauroglycol FCC, 45% v/v Tween 80, 45% v/v ethanol, and 0.005% w/v glimepiride. Further, the optimized liquid SNEDDS were solidified through spray drying using various hydrophilic and hydrophobic carriers. Among the various carriers, Aerosil 200 was found to provide desirable flow, compression, dissolution, and diffusion. Both, liquid and solid-SNEDDS have shown release of more than 90% within 10 min. Results of permeation studies performed on Caco-2 cell showed that optimized SNEDDS exhibited 1.54 times higher drug permeation amount and 0.57 times lower drug excretion amount than that of market tablets at 4 hours (p < .01). Further, the cytotoxicity study performed on Caco-2 cell revealed that the cell viability was lower in SNEDDS (92.22% ± 4.18%) compared with the market tablets (95.54% ± 3.22%; p > .05, i.e. 0.74). The formulation was found stable with temperature variation and freeze thaw cycles in terms of droplet size, zeta potential, drug precipitation and phase separation. Crystalline glimepiride was observed in amorphous state in solid SNEDDS when characterized through DSC, PXRD, and FT-IR studies. The study revealed successful formulation of SNEDDS for glimepiride.

Assessment of Combined Ascorbyl Palmitate (AP) and Sodium Ascorbyl Phosphate (SAP) on Facial Skin Sebum Control in Female Healthy Volunteers.

The skin is fortified with a setup of lipophilic and hydrophilic, enzymatic and non-enzymatic antioxidant systems. Ascorbyl palmitate (AP) and sodium ascorbyl phosphate (SAP) are reported as lipophilic and hydrophilic antioxidants, respectively used for skin care. Present study was aimed to assess the combined AP (in oil phase) and SAP (in aqueous phase) via multiple emulsion (ME1) for controlling sebum secretions in healthy human females. FTIR analysis of AP and SAP was performed for identification. Multiple emulsions (ME1 and control) were prepared and analyzed for physical stability. Antioxidant activities of AP, SAP as well as ME1 (with combination of these compounds) were determined by DPPH method. 11 female volunteers were included in a single-blinded, placebo-controlled, split-face comparative study. Volunteers were instructed to apply ME1 on left cheek while control (without AP and SAP) on right cheek, for a period of 90 days. A non-invasive photometric device (Sebumeter®) was used for the measurement of sebum secretions on both sides of the face with subsequent time intervals. A good antioxidant activity of ME1 was observed. ME1 treatments reduced significant facial sebum secretions as compared with control/placebo treatments. It was concluded that combined AP and SAP supplementations to skin proved a promising choice for controlling facial sebum secretions and could be evaluated for undesired oily skin and acne reductions for beautifying the facial appearance.

Anti-Candida activity assessment of Pelargonium graveolens oil free and nanoemulsion in biofilm formation in hospital medical supplies.

Infections due to microbial biofilm formation on the surface of catheters and other medical devices are constantly reported as a major cause of morbidity and mortality in patients admitted to hospitals. Furthermore, sessile cells are more resistant to phagocytosis and most antimicrobial, which complicates the treatment of such infections. Researches aimed at new antimicrobial originating mainly from plants have increased in recent years and the development of new strategies for their release is critical in combating the formation of biofilms. Geranium oil (GO) has proven antimicrobial activity. Because of this, the aim of this study was to develop nanoemulsions containing this oil (NEG) and evaluate its activity after the biofilm formation of Candida albicans, Candida tropicalis, Candida glabrata, and Candida krusei in hospital medical supplies. For quantification of the biofilm, crystal violet, total protein, and ATP-bioluminescence assays were used. The results revealed that GO and NEG showed lower MIC for C. albicans and C. tropicalis. The biofilms formed by different species of Candida on the surfaces of polyethylene and polyurethane were quantified. GO and NEG significantly inhibited the formation of biofilms in all species tested on the surfaces of polyethylene. However, NEG antibiofilm has had better activity than GO for C. albicans, C. tropicalis and C. glabrata, according to the surface potential analysis by atomic force microscopy (AFM). The analysis of the biofilm formation on the polyethylene surface by ATP-bioluminescence and CFU showed similar results. In both methods the formation of biofilm in the catheter occurred in greater quantity for C. albicans and C. tropicalis. GO did not significantly inhibit the formation of biofilms only in C. krusei, although NEG significantly increased this activity GO in all species tested when compared to the control training biofilm. The following study shows that the development of NEG may become an effective alternative to reduce the adhesion of microorganisms and prevent infections resulting from the use of some hospital medical materials.

Development and assessment of stable formulations containing two herbal antimicrobials: Allium sativum L. and Eruca sativa miller seed oils.

CONTEXT: Garlic oil and Eruca oil have been reported to have excellent antimicrobial activity. However, the exact knowledge of their required hydrophilic-lipophilic balance (rHLB) values to facilitate their emulsification are still not reported in the literature. OBJECTIVE: The objective of this study is to determine rHLB values of Garlic and Eruca oils to formulate an elegant stable cream formulation enriched with both oils. MATERIALS AND METHODS: Emulsions of both oils were prepared by the bottle method using water, Tween 80 and Span 80. Formulated emulsions were evaluated for creaming index (CI), droplet size, and turbidity to determine rHLB. Utilizing determined rHLB, creams were formulated using a combination of two surfactants, Span 60:Brij 58 (1:2.333) at three different concentrations (2, 4, and 6%). RESULTS: rHLB of Garlic oil and Eruca oil was determined to be 7.92 ± 0.27 and 9.76 ± 0.32, respectively. Stable cream (F1) developed with 2% surfactant blend showed elegant rheological properties, the best antimicrobial activity against Staphyococcus aureus ATCC29737, Escherichia coli ATCC25299 S. aureus (MRSA), Malassezia fufur AUMC No. 5173 with no skin irritation. In addition, its texture parameters and pH were found to be consistent over 12 months at 25 ± 1 °C and 60% relative humidity. DISCUSSION: The lowest CI, smallest droplet size, and highest turbidity were obtained at the optimum surfactant concentration in the prepared emulsions. Increasing surfactant blend concentration in cream formulations leads to increasing viscosity and consequently decreasing antimicrobial activity. CONCLUSION: Determination of the rHLB of Garlic and Eruca oils allows the ease of preparation of stable, consistent, and non-irritant cream.

Naltrexone-loaded poly[La-(Glc-Leu)] polymeric microspheres for the treatment of alcohol dependence: in vitro characterization and in vivo biocompatibility assessment.

The poly[La-(Glc-Leu)] copolymer was applied in the present investigation as polymeric carrier to fabricate naltrexone (NTX)-loaded poly[La-(Glc-Leu)] microspheres in the single emulsion solvent evaporation technique for the long-term treatment of alcohol dependence. Newly synthesized poly[La-(Glc-Leu)] copolymer exhibited diminished crystallanity, good biocompatibility and favorable biodegradability to be explored for drug delivery application. Scanning Electron Microscopy study revealed smooth and spherical-shaped NTX-loaded polymeric microspheres with a mean size of 10-90 µm. Influence of various decisive formulation variables such as amount of polymer, stabilizer concentration, homogenization speed, homogenization time, drug loading and organic-to-aqueous phase ratio on particle size, and entrapment efficiency was studied. Differential scanning calorimeter and X-ray diffractometry study confirmed the drug entrapment within polymer matrix into the microsphere environment. In vitro drug release showed the sustained drug release of formulation for the period of 28 d giving biphasic release pattern. Histological examination of NTX-loaded poly[La-(Glc-Leu)] microspheres injected intramuscularly into the thigh muscle of Wistar rats showed minimal inflammatory reaction, demonstrating that NTX-loaded microspheres were biocompatible. Insignificant increase in the serum creatine phosphokinase level (p < 0.05) as compared with the normal value revealed good muscle compatibility of the poly[La-(Glc-Leu)] microsphere system. Biocompatible nature and sustained drug-release action of poly[La-(Glc-Leu)] microspheres may have potential application in depot therapy.

Stability and sensory assessment of emulsions containing propolis extract and/or tocopheryl acetate / Estabilidade e avaliação sensorial de emulsões que contêm extracto de própolis e / ou acetato de tocoferol

The prevention of skin aging has been one of the main aims of cosmetic products. Propolis and tocopheryl acetate can be promising substances because of their antioxidant properties. In this study, propolis extract was obtained and associated with tocopheryl acetate in a cream formulation, which then underwent stability and sensory assessment. The formulation containing propolis extract and tocopheryl acetate proved to be stable in the preliminary stability study, demonstrating gradual darkening and slight pH decrease when subjected to 60ºC for 28 days, but showing stability on rheological study. In the sensory analysis, the formulation containing these two components was preferred by the product testers over the base cream and creams containing propolis extract or tocopheryl acetate alone. In conclusion, given the stability of the formulation and the preference of the product testers for this formulation, this association proved promising for use in cosmetic formulations.

A prevenção do envelhecimento cutâneo tem sido um dos principais focos dos produtos dermocosméticos. A própolis contém substâncias com atividade antioxidante, bem como o acetato de tocoferila é conhecido por apresentar esta atividade. Porém, a própolis apresenta odor muito característico e intenso, que pode interferir no sensorial do produto. Assim, no presente trabalho, obteve-se o extrato de própolis, que foi associado ao acetato de tocoferila em uma formulação de uso tópico, que foi avaliada quanto à estabilidade e às características sensoriais. Conduziu-se um estudo de estabilidade, no qual as formulações contendo ambos os compostos apresentaram escurecimento gradual e ligeira queda no pH após 28 dias sob 60 °C, tendo sido estável no estudo reológico. Na análise sensorial, realizada com 28 provadores, a formulação contendo extrato de própolis em associação com acetato de tocoferila foi a preferida, quando comparada com o creme base e o creme contendo somente extrato de própolis ou acetato de tocoferila. Em conclusão, devido à preferência dos provadores e ao estudo de estabilidade, a associação de extrato de própolis e de acetato de tocoferila mostrou ser promissora para uso em produtos dermocosméticos.

Avaliação da estabilidade e atividade antioxidante de uma emulsão base não-iônica contendo resveratrol / Evaluation of antioxidant activity and stability of an emulsion base containing non-ionic resveratrol

Vários são os fatores que podem ocasionar a instabilidade de uma emulsão, destacando-se a oxidação, reação prevenida pelo emprego de antioxidantes. O butil-hidróxi-tolueno (BHT) tem sido um dos antioxidantes sintéticos mais utilizados em formulações cosméticas, porém, a busca da indústria farmacêutica e cosmética pelo emprego de produtos de origem natural tem sido cada vez maior. Visto isso, o objetivo do presente trabalho foi a incorporação do resveratrol, um composto fenólico encontrado principalmente em uvas bem como em vinhos tintos, em uma emulsão base não-iônica para avaliação do perfil de estabilidade e atividade antioxidante em comparação a uma emulsão base não-iônica contendo o BHT. O perfil de estabilidade foi analisado pela observação das características organolépticas, determinação do pH e espalhabilidade, e atividade antioxidante através do teste com o radical livre 2,2-difenil-1-picrilhidrazila (DPPH). Em relação à estabilidade, a altas temperaturas, a emulsão contendo BHT mostrou-se superior à emulsão contendo resveratrol. Pela análise da atividade antioxidante, o resveratrol tanto na sua forma de extrato seco, como quando incorporado na emulsão, demonstrou significativa superioridade em relação ao BHT, podendo ser sua utilização uma alternativa viável em preparações cosméticas, devido ao seu grande potencial antioxidante.

There are several factors that can lead to the instability of an emulsion, highlighting the oxidation, a reaction prevented by the use of antioxidants. The butylated hydroxytoluene (BHT) has been one of the most used synthetic antioxidants in cosmetic formulations; however, pharmaceutical and cosmetic industries have shown considerable interest regarding the search for the use of natural products. Based on this, the objective of this work was the incorporation of resveratrol, a natural phenolic compound found mainly in grapes as well as in red wines, into a non-ionic emulsion basis for assessing the profile of stability and antioxidant activity, as compared with a non-ionic basis emulsion containing BHT. The profile of stability was examined by the observation of the organoleptic characteristics, determination of pH and spreadability, and the antioxidant activity through the Radical Scavenging DPPH test. The results showed that the emulsion containing BHT was more stable than the emulsion containing resveratrol, when high temperature was used. For the analysis of the antioxidant activity, the resveratrol, in both forms of incorporation, showed significant antioxidant activity in comparison to BHT, suggesting that resveratrol may be a viable antioxidant alternative to be used into cosmetic preparations.