Fabrication of Alginate-Based O/W Nanoemulsions for Transdermal Drug Delivery of Lidocaine: Influence of the Oil Phase and Surfactant

Transdermal drug delivery of lidocaine is a good choice for local anesthetic delivery. Microemulsions have shown great effectiveness for the transdermal transport of lidocaine. Oil-in-water nanoemulsions are particularly suitable for encapsulation of lipophilic molecules because of their ability to form stable and transparent delivery systems with good skin permeation. However, fabrication of nanoemulsions containing lidocaine to provide an extended local anesthetic effect is challenging. Hence, the aim of this study was to address this issue by employing alginate-based o/w nanocarriers using nanoemulsion template that is prepared by combined approaches of ultrasound and phase inversion temperature (PIT). In this study, the influence of system composition such as oil type, oil and surfactant concentration on the particle size, in vitro release and skin permeation of lidocaine nanoemulsions was investigated. Structural characterization of lidocaine nanoemulsions as a function of water dilution was done using DSC. Nanoemulsions with small droplet diameters (d < 150 nm) were obtained as demonstrated by dynamic light scattering (DLS) and cryo-TEM. These nanoemulsions were also able to release 90% of their content within 24-h through PDMS and pig skin and able to the drug release over a 48-h. This extended-release profile is highly favorable in transdermal drug delivery and shows the great potential of this nanoemulsion as delivery system.     

Generating Multidirectional Variable Hidden Attractors via Newly Commensurate and Incommensurate Non-Equilibrium Fractional-Order Chaotic Systems

This article investigates a non-equilibrium chaotic system in view of commensurate and incommensurate fractional orders and with only one signum function. By varying some values of the fractional-order derivative together with some parameter values of the proposed system, different dynamical behaviors of the system are explored and discussed via several numerical simulations. This system displays complex hidden dynamics such as inversion property, chaotic bursting oscillation, multistabilty, and coexisting attractors. Besides, by means of adapting certain controlled constants, it is shown that this system possesses a three-variable offset boosting system. In conformity with the performed simulations, it also turns out that the resultant hidden attractors can be distributively ordered in a grid of three dimensions, a lattice of two dimensions, a line of one dimension, and even arbitrariness in the phase space. Through considering the Caputo fractional-order operator in all performed simulations, phase portraits in two- and three-dimensional projections, Lyapunov exponents, and the bifurcation diagrams are numerically reported in this work as beneficial exit results.     

Synthesis and properties of symm-triazines. 3. Reactions of 2-alkyl-4,6-bistrichloromethyl-symm-triazines containing higher alkyl groups with ammonia and aliphatic amines

The reaction of 2-alkyl-4,6-bistrichloromethyl-symm-triazines containing higher alkyl groups with ammonia or aliphatic amines results, depending on the reaction conditions, in the replacement of one or both trichloromethyl groups. On heating these symm-triazines with aqueous ammonia or dimethylamine, 2-oxo-4-amino-6-alkyl-1(3)H-symm-triazines are obtained.For communication 2, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1557–1563, November, 1985.     

Synthesis and properties of furan derivatives. 4. Synthesis of 2,5-disubstituted 1,3,4-oxadiazoles containing furan fragments

The condensation of hydrochloride sats of iminoesters of furan acids with hydrazides of carboxylic acids gives 2,5-disubstituted 1,3,4-oxadiazoles containing furan fragments. Such compounds are also formed in the condensation of hydrazides of 5-R-furan-2-carboxylic acids with hydrocloride salts of carboxylic acid iminoesters. The reaction of furan acids with hydrazine dihydrochloride in polyphosphoric acid gave symmetrically disubstituted 1,3,4-oxadiazoles containing furan fragments.Communication 3, see ref. [1].I. M. Gubkin State Petroleum and Natural Gas Institute, 117917, Moscow. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 238–249, February, 1995. Original article submitted January 24, 1995.     

Synthesis and properties of sym-triazine derivatives. 3. alkoxylation of 2-alkyl-4,6-bis(trichloromethyl)-sym-triazines containing higher alkyl radicals

Nucleophilic substitution reactions of trichloromethyl groups in 2-alkyl-4,6-bis-(trichloromethyl)-sym-triazines by alkoxy radicals were studied. It was shown that in the presence of sodium alcoholates, two CCl₃ groups are replaced, and the corresponding 2,4-dialkoxy-6-alkyl-sym-triazines are formed. The products of partial replacement, 2-alkoxy-4-trichloromethyl-6-alkyl-sym-triazines, were synthesized by heating the initial sym-triazines with alcohols in the presence of tertiary amines.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1674–1677, December, 1984.     

THEORETICAL STUDY OF PENTAVALENT HALOSILICONATES: STRUCTURE AND CHARGE DELOCALIZATION

Journal of Structural Chemistry - This study is performed to detect the pentavalent silicon center in the structure of pentavalent-halosiliconate R–O–Si(CH3)3X– and...     

Chemical composition,antioxidant and antibacterial properties of Pteranthus dichotomus from Algerian Sahara

The phytochemical study of ethyl acetate and n-butanol extracts of Pteranthus dichotomus Forssk. led to the isolation and identification of 11 compounds, including three glycolipids 1–3, one lignan 4, three flavonoids 5–7 and four phytosterols 8–11. Structures of the isolated compounds have been elucidated by analysis of 1D and 2D NMR data, and mass spectrometry EI-MS and ESI-MS and by comparison with literature data. Furthermore, the ethyl acetate and n-butanol extracts were examined for their antioxidant and antibacterial activities. The results showed that both extracts (PDAC and PDBU) had a moderate antioxidant activity (IC50 = 375.514 μg/mL and 691.333 μg/mL) respectively.     

Synthesis and properties of derivatives of sym-triazine. 5. Synthesis and mass spectrometric study of carbamide derivatives of sym-triazine

The reaction of 2-amino- and 2,4-diamino-sym-triazines with nitrourea and phenyl isocyanate was studied; it gives N-mono- and N,N-disubstituted ureas that contain sym-triazine segments. General features were established for the decomposition of carbamide derivatives of sym-triazine under electron impact.For communication 4, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 356–362, March, 1987.