Chemical composition and antibacterial activity of essential oil of <i>Nepeta graciliflora</i> Benth. (Lamiaceae)

<p>The chemical composition of the essential oil obtained from aerial parts of <i>Nepeta graciliflora</i> was analysed, for the first time, by GC–FID and GC–MS. A total of 27 compounds were identified, constituting over 91.44% of oil composition. The oil was strongly characterised by sesquiterpenes (86.72%), with <i>β</i>-sesquiphellandrene (28.75%), caryophyllene oxide (12.15%), <i>α</i>-bisabolol (8.97%), <i>α</i>-bergamotene (8.51%), <i>β</i>-bisabolene (6.33%) and <i>β</i>-Caryophyllene (5.34%) as the main constituents. The <i>in vitro</i> activity of the essential oil was determined against four micro-organisms in comparison with chloramphenicol by the agar well diffusion and broth dilution method. The oil exhibited good activity against all tested organisms.</p

Interaction of an Amphiphilic Drug Trifluoperazine Dihydrochloride with Pluronic Triblock Copolymers: A Physicochemical Study

In the present study, we report the interactional behavior of the phenothiazine drug trifluoperazine dihydrochloride (TFP) with Pluronics (L64, F68, and P123) using surface tension, cloud point and fluorescence measurements. Various micellar and interfacial parameters such as critical micellization concentration (cmc), interaction parameter (β), effectiveness of surface tension reduction (π_cmc), maximum surface excess concentration (Γ_max), and minimum area per molecule (<i>A</i>_min) at the air–water interface have been evaluated using surface tension technique. The phase separation behavior of the drug is studied in the presence of Pluronics, and the corresponding thermodynamic parameters such as Gibbs free energy (Δ<i>G</i>°_c), standard enthalpy (Δ<i>H</i>°_c), and entropy (<i>T</i>Δ<i>S</i>°_c) of clouding have been calculated. Employing the steady state fluorescence measurements, the interactions between the drug and Pluronics have been determined in terms of the number of binding sites for drug molecules (<i>n</i>), binding constants (<i>K</i>_a), and Stern–Volmer quenching constants (<i>K</i>_sv)

An Investigation of Drug Binding Ability of a Surface Active Ionic Liquid: Micellization, Electrochemical, and Spectroscopic Studies

Keeping in view the use of surfactants in drug delivery, the interactions of surface active ionic liquids, such as 1-tetradecyl-3-methylimidazolium bromide (C₁₄mimBr), with drugs, viz., dopamine hydrochloride (DH) and acetylcholine chloride (AC), have been studied, and the results are further compared with that of the structurally similar conventional cationic surfactant tetradecyltrimethylammonium bromide (TTAB). The micellization and interfacial behavior of C₁₄mimBr and TTAB, in the presence of DH and AC, has been investigated from conductivity and surface tension measurements. Various micellar and adsorption characteristics for these drug–surfactant systems (DH/AC + C₁₄mimBr/TTAB) have been investigated, indicating favorable interactions between them. The more detailed information regarding the nature of interactions between C₁₄mimBr/TTAB and DH/AC is obtained from cyclic voltammetry (CV) and ¹H NMR measurements. CV measurements have been employed to evaluate the binding constant (<i>K</i>) and the Gibbs free energy change (Δ<i>G</i>) for these drug–surfactant complexes. These measurements indicate the existence of cation−π as well as π–π interactions between drugs and surfactants. A detailed analysis of chemical shifts of protons of drug molecules (DH and AC) in the presence of C₁₄mimBr and TTAB has been done by ¹H NMR. The results obtained from ¹H NMR are in agreement with those of CV measurements. ¹H NMR studies along with the conductivity and surface tension measurements help in predicting the possible location of adsorption of these drug molecules in C₁₄mimBr and TTAB micelles