Formulation and evaluation of detarium oil based organogel for sustained release of metronidazole via topical delivery

The rationale for this study was to increase the absorption of model drug metronidazole by formulating an organogel using detarium oil in place of conventional oils used in drug formulation such as liquid paraffin. The organogels were prepared by fluid-filled mechanism using metronidazole as the model drug. The drug-surfactant mixtures were dissolved in oil followed by the addition of water which led to the formation of organogels at specific compositions. The formulations were analyzed by microscopy, rheology, in vitro drug release and X-ray diffraction (XRD). Microscopic studies revealed the gels contained clusters of water-filled spherical structures. FTIR study showed compatibility of components of the organogels. DSC result showed all the organogels released heat during formation. The viscosity of the organogels showed an elastic flow followed by a non-elastic phase. The cumulative percentagerelease of metronidazole was found to be between 63% and 85% at the end of 10 h, with OGM 9 having the highest release. XRD result indicated the crystalline nature of the organogels. Metronidazole release from the organogels indicated dissolution, shape, size, and surface area dependent release. The results also showed good compatibility of all the excipients. Sustained release metronidazole organogel was successfully developed using detarium oil. Keywords: Organogel; Detarium oil; Metronidazole; Topical delivery

Evaluation of two thioesterases from Marinobacter aquaeolei VT8: Relationship to wax ester production

The biosynthesis of lipid-based biofuels is an important aspect of developing sustainable alternatives to conventional oils derived from fossil fuel reserves. Many biosynthetic approaches to biodiesel fuels and oils involve fatty acid derivatives as a precursor, and thioesterases have been employed in various strategies to increase fatty acid pools. Thioesterases liberate fatty acids from fatty acyl-coenzyme A or fatty acyl-acyl carrier protein substrates. The role played by thioesterases has not been extensively studied in model bacteria that accumulate elevated levels of biological oils based on fatty acid precursors. In this report, two primary thioesterases from the wax ester accumulating bacterium Marinobacter aquaeolei VT8 were heterologously expressed, isolated and characterized. These genes were further analyzed at the transcriptional level in the native bacterium during wax ester accumulation, and their genes were disrupted to determine the effect these changes had on wax ester levels. Combined, these results indicate that these two thioesterases do not play an integral role in wax ester accumulation in this natural lipid-accumulating model bacterium.

Comparative study of physicochemical properties of Tithonia diversifolia and Sunflower seed oils

This study investigates the physico-chemical properties of Tithonia diversifolia seed and oil using standard analytical methods and then compared the results with Sunflower oil. The results showed that Tithonia diversifolia seed contained 5.80% moisture, 18.83% crude protein, 30.40% crude fat, 17.85% crude fibre, 4.30% ash and 22.82% carbohydrate. The content of magnesium, copper, iron, zinc and calcium were 3930, 168, 277, 2091 and 432 mg/kg, respectively. Iodine value for T. diversifolia and Sunflower oils, respectively were 109.00 and 145.67 g iodine/kg; saponification values, 212.61 and 188.63 mg KOH/g; ester values, 184.15 and 206.86 mg KOH/g; peroxide values 4.0 and 5.87 meq peroxide/kg; acid values, 5.76 and 4.48 mg KOH / g; % unsaponifiable matter, 0.83 and 1.22 %; and total phenol content, 118.63 and 108.75 µg/g. Others include, specific gravity, 0.937 and 0.920; surface tension 0.042 and 0.051 N/m; viscosity 42.50 and 30.50 cSt; and smoke point, 215 and 245 0C. The study revealed that Tithonia diversifolia seed oil content and physicochemical parameters are comparable with those of Sunflower oil. Hence the oil could be used as raw materials for industrial processes, biodiesel production and a good source of dietary antioxidant which could complement or replace some conventional oils.

Seeds of Zizyphus lotus: In Vivo Healing Properties of the Vegetable Oil

The present study has been undertaken in order to highlight the healing effect of Zizyphus lotus vegetable oil. The seeds of this plant contain an oil rate of 30%. The obtained results on the main elements composing the vegetable oil have shown that Zizyphus lotus vegetable oil has a low value of acidity index and it presents a not negligible degree of unsaturation. The value of the peroxide index of Zizyphus lotus vegetable oil is less than 10 which characterizes the most of conventional oils. Furthermore, the spectral analysis by gas chromatography has shown the presence of 53 majority and minority molecules. Thus, the evaluation of the healing activity of Z. lotus seed vegetable oil has demonstrated a highly significant effect against the negative control and silver sulfadiazine was used as conventional treatment for burns. Based on the obtained results, we can suggest that the oil extracted from the seeds of the studied plant could be used to cure wounds.

Facile methodology of nanoemulsion preparation using oily polymer for the delivery of poorly soluble drugs

Aqueous solubility of an active pharmaceutical ingredient (API) is a determining factor that has a direct impact on formulation strategies and overall bioavailability. Fabrication of nanoemulsions of poorly soluble drugs is one of the widely utilized approaches to overcome this problem. However, thermodynamic instability and tedious manufacturing processes of nanoemulsions limit their clinical translation. Therefore, this study was focused on circumventing the abovementioned hurdles by utilizing the polymer as an oil phase, instead of conventional oils. The nanoemulsion was prepared via a facile low-energy nanoprecipitation method using renewable poly(δ-decalactone) (PDL), as an oil phase and Pluronic F-68 as surfactant. The prepared nanoemulsions were characterized in terms of size, drug encapsulation efficiency, stability, and toxicity. Five different hydrophobic drugs were utilized to evaluate the drug delivery capability of the PDL nanoemulsion. The prepared nanoemulsions with sizes less than 200 nm were capable to enhance the aqueous solubility of the drugs by 3 to 10 times compared with the well-established Pluronic F-68 micelles. No phase separation or significant changes in size and drug content was observed with PDL nanoemulsions after high-speed centrifugation and 3 months of storage at two different temperatures (20 °C and 50 °C). PDL nanoemulsions were found to be non-heamolytic up to concentrations of 1 mg/mL, and the cell cytotoxicity studies on MDA-MB-231 and MEF cells suggest a concentration and time-dependent toxicity, where the PDL polymer itself induced no cytotoxicity. The results from this study clearly indicate that the PDL polymer has a tremendous potential to be utilized as an oil phase to prepare stable nanoemulsions via a facile methodology, ultimately favouring clinical translations.

Ensuring the quality of the machined holes during the hole truing and reaming on lathe machines

The article is devoted to studying of the influence of cutting liquids, including those of plant origin, on the roughness of the treated surface during the reaming and deployment in details of titanium alloy, structural and corrosion-resistant steels. The relationships between the characteristics of the adhesive interaction of the tool and the processed materials and the length of the contact area of the tool with the workpiece and heat in the cutting zone are determined. The effectiveness of plant-origin cutting liquids is shown in comparison with conventional oils under conditions of the pronounced adhesive wear.

Case Studies from a Canadian Response Organization: 20 Years in Review

ECRC~SIMEC is one of four government certified response organizations (RO) providing marine spill response services to the shipping industry and oil handling facilities operating in Canada. ECRC's client membership includes over 2300 members in total, comprised of approximately 2200 vessel members and close to 100 oil handling facilities. With its vast geographic area of response, bordered by the Canadian Rockies to the west, the Great Lakes in the south, Hudson Bay in the north and Canada's exclusive economic zone in the east, ECRC~SIMEC has had the opportunity to respond to spills in a variety of environments. Response to oil spills in at sea, in rivers, lakes and estuaries have required the ability to adapt to challenging environments such as fast flowing waters, large tidal ranges, ice, and remote locations. In addition to ship source spills, ECRC~SIMEC has gained considerable experience responding to spills from pipelines and rail incidents, which have impacted waterways, most notably the spill following the Lac Mégantic derailment in 2013. The company, which recently marked its 20th year anniversary, has taken the opportunity to look back at incidents attended and lessons learned over the years and to reflect on the resulting changes to its response capability and capacity. This paper will provide an overview of roles and responsibilities of a certified response organization within the context of the Canadian marine spill response regime and provide a retrospective look at incidents attended over the last 20 years. Cases of particular interest will be highlighted with a focus on responses in winter conditions and to non-conventional oils. This paper will briefly outline the regulatory framework that governs ROs preparedness and response to ship source spills in Canada and focus on the lessons learned from key incidents over the history of the company's existence.