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Purpose: Although the effective and safe medical defoamers, dimethicone (DM) and simethicone (SM) are widely used in electronic gastroscope examination (EGE), their preparations are presented in the form of suspensions or emulsions, these are untransparent or milk-like in appearance and can easily cause misdiagnosis as a result of an unclear field of vision if the doctor does not master the amount of defoamer or operates incorrectly. At the same time, it is also difficult to wash out the camera and pipeline, due to the large oil droplets of preparations. The purpose of this study was to develop a new clear and transparent oil in water (O/W) DM nanoemulsions (DMNs) and observe the effect of application in EGE., Methods: The oil phase was chosen for its antifoaming activity and viscosity. The emulsifier and co-emulsifier were selected according to the solubility of the oil phase in them. The water titration method was used to make the pseudoternary phase diagrams of nanoemulsions and optimize the prescription composition. DM-in-water nanoemulsion was prepared by the low energy method and evaluated for appearance, antifoaming ability, droplet size, and stability. The effect of DMNs utilized in EGEs was also observed., Results: The optimal formulation of DMNs contained CRH-40 as an emulsifier, PEG-400 as a co-emulsifier, DM as oil phase with the viscosity of 10 mPa.s, and their proportion was 4.5:4.5:1, respectively. DMNs obtained the average particle size of 67.98 nm with the polydispersity index (PDI) of 0.332, and 57.14% defoaming rate. The result of using an EGE showed that DMNs were superior in comparison to the emulsions with regard to the defoaming effect, visual clarity, and easy cleanup., Conclusion: DMNs were found to provide excellent visual clarity to its other preparations. The novel DMNs is a promising substitute for DM emulsions or suspensions in EGEs., Competing Interests: The authors report no conflicts of interest in this work., (© 2020 Feng et al.)

Background: New anticancer agents that rely on natural/healthy, not synthetic/toxic, components are very much needed., Methods: Ricinoleyl hydroxamic acid (RHA) was synthesized from castor oil and hydroxylamine using Lipozyme TL IM as a catalyst. To optimize the conversion, the effects of the following parameters were investigated: type of organic solvent, period of reaction, amount of enzyme, the molar ratio of reactants and temperature. The highest conversion was obtained when the reaction was carried out under the following conditions: hexane as a solvent; reaction period of 48 hours; 120 mg of Lipozyme TL IM/3 mmol oil; HA-oil ratio of 19 mmol HA/3 mmol oil; and temperature of 40°C. The cytotoxicity of the synthesized RHA was assessed using human dermal fibroblasts (HDF), and its application towards fighting cancer was assessed using melanoma and glioblastoma cancer cells over a duration of 24 and 48 hours., Results: RHA was successfully synthesized  and it demonstrated strong anticancer activity against glioblastoma and melanoma cells at as low as a 1 µg/mL concentration while it did not demonstrate any toxicity against HDF cells., Conclusion: This is the first report on the synthesis of RHA with great potential to be used as a new anticancer agent., Competing Interests: The authors report no conflicts of interest in this work., (© 2020 Jahangirian et al.)

Three tilmicosin-loaded hydrogenated castor oil nanoparticle (TMS-HCO-NP) suspensions of different particle sizes were prepared with different polyvinyl alcohol surfactant concentrations using a hot homogenization and ultrasonic technique. The in vitro release, in vitro antibacterial activity, mammalian cytotoxicity, acute toxicity in mice, and stability study were conducted to evaluate the characteristics of the suspensions. The in vitro tilmicosin release rate, antibacterial activity, mammalian cytotoxicity, acute toxicity in mice, and stability of the suspensions were evaluated. When prepared with polyvinyl alcohol concentrations of 0.2%, 1%, and 5%, the mean diameters of the nanoparticles in the three suspensions were 920±35 nm, 452±10 nm, and 151±4 nm, respectively. The three suspensions displayed biphasic release profiles similar to that of freeze-dried TMS-HCO-NP powders, with the exception of having a faster initial release. Moreover, suspensions of smaller-sized particles showed faster initial release, and lower minimum inhibitory concentrations and minimum bactericidal concentrations. Time-kill curves showed that within 12 hours, the suspension with the 151 nm particles had the most potent bactericidal activity, but later, the suspensions with larger-sized particles showed increased antibacterial activity. None of the three suspensions were cytotoxic at clinical dosage levels. At higher drug concentrations, all three suspensions showed similar concentration-dependent cytotoxicity. The suspension with the smallest-sized particle showed significantly more acute toxicity in mice, perhaps due to faster drug release. All three suspensions exhibited good stability at 4°C and at room temperature for at least 6 months. These results demonstrate that TMS-HCO-NP suspensions can be a promising formulation for tilmicosin, and that nanoparticle size can be an important consideration for formulation development.

Silver nanoparticles were fabricated by ablation of a pure silver plate immersed in castor oil. A Nd:YAG-pulsed Q-switch laser with 1064-nm wavelength and 10-Hz frequency was used to ablate the plate for 10 minutes. The sample was characterized by ultraviolet-visible, atomic absorption, Fourier transform-infrared spectroscopies, and transmission electron microscopy. The results of the fabricated sample showed that the nanoparticles in castor oil were about 5-nm in diameter, well dispersed, and showed stability for a long period of time.

We have reported a novel procedure to prepare 3,5-dihydroxy-4-isopropylstilbene (DHPS) nanoemulsion, using a low-energy emulsification method. Based on the phase diagram, the optimum prescription of nanoemulsion preparation was screened. With polyoxyethylenated castor oil (EL-40) as the surfactant, ethanol as the co-surfactant, and isopropyl myristate (IPM) as the oil phase, the DHPS nanoemulsion was obtained with a transparent appearance, little viscosity, and spherically uniform distribution verified by transmission electron microscopy and laser scattering analyzer. The nanoemulsion was also determined by FT-Raman spectroscopy. The DHPS nanoemulsion demonstrated good stability and stable physical and chemical properties. The nanoemulsion dramatically improved the transdermal release of DHPS (from 8.02 μg · cm(-2) to 273.15 μg · cm(-2)) and could become a favorable new dosage form for DHPS.

Hydatid disease caused by tapeworm is an increasing public health and socioeconomic concern. In order to enhance the therapeutic efficacy of praziquantel (PZQ) against tapeworm, PZQ-loaded hydrogenated castor oil solid lipid nanoparticle (PZQ-HCO-SLN) suspension was prepared by a hot homogenization and ultrasonication method. The stability of the suspension at 4°C and room temperature was evaluated by the physicochemical characteristics of the nanoparticles and in-vitro release pattern of the suspension. Pharmacokinetics was studied after subcutaneous administration of the suspension in dogs. The therapeutic effect of the novel formulation was evaluated in dogs naturally infected with Echinococcus granulosus. The results showed that the drug recovery of the suspension was 97.59% ± 7.56%. Nanoparticle diameter, polydispersivity index, and zeta potential were 263.00 ± 11.15 nm, 0.34 ± 0.06, and -11.57 ± 1.12 mV, respectively and showed no significant changes after 4 months of storage at both 4°C and room temperature. The stored suspensions displayed similar in-vitro release patterns as that of the newly prepared one. SLNs increased the bioavailability of PZQ 5.67-fold and extended the mean residence time of the drug from 56.71 to 280.38 hours. Single subcutaneous administration of PZQ-HCO-SLN suspension obtained enhanced therapeutic efficacy against tapeworm in infected dogs. At the dose of 5 mg/kg, the stool-ova reduction and negative conversion rates and tapeworm removal rate of the suspension were 100%, while the native PZQ were 91.55%, 87.5%, and 66.7%. When the dose reduced to 0.5 mg/kg, the native drug showed no effect, but the suspension still got the same therapeutic efficacy as that of the 5 mg/kg native PZQ. These results demonstrate that the PZQ-HCO-SLN suspension is a promising formulation to enhance the therapeutic efficacy of PZQ.