Objective: Exemestane is an anti-breast cancer drug, possesses low water solubility and low permeability. This work aimed at the cause-effect relations and optimization of exemestane-loaded nanostructured lipid carriers (EXE-NLCs) for oral delivery.Methods: Excipient screening was based on exemestane solubilities and the emulsification efficiency of surfactants. A D-optimal design based on three independent variables was applied to evaluate the cause-effect relations and optimise EXE-NLCs formulation. The particle size (PS), polydispersity index (PDI), entrapment efficiency (EE) and drug loading (DL) were investigated with respect to three independent variables including liquid lipid to total lipid ratio (X1), surfactant concentration (X2), total lipid concentration (X3).Results: EXE-NLCs were prepared by a hot sonication method employing Labrafac CC and Compritol 888ATO as liquid and solid lipids, respectively, and Cremophor RH40 as a surfactant and Lutrol E-400 as a co-surfactant. All investigated factors: liquid lipid to total lipid ratio, surfactant concentration and total lipid concentration showed significant influences on physicochemical characteristics of EXE-NLCs. The optimal EXE-NLC formulation was composed of liquid lipid to total lipid ratio (X1) of 24 % (w/w), surfactant concentration (X2) of 4 % (w/v) and total lipid concentration (X3) of 4 % (w/v). The PS, PDI, EE and DL of the optimized EXE-NLCs were found to be 41.787 nm; 0.11; 97.605 % and 1.935 %, respectively. The optimized formulation was experimentally examined which demonstrated a good agreement between experimental and predicted values. Conclusion:The cause-effect relations and optimization of EXE-NLCs were investigated and reported for the first time. EXE-NLCs formulation was successfully optimized using D-optimal design and merits further study.

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A new isoflavanone, (3S)-5,7-dihydroxy-2′,3′,4′-trimethoxy-6,5′-diprenylisoflavanone (1) and eight known compounds including five flavones (2-6), two triterpenes (7-8) and a steroid (9) were isolated from the whole plant of Uraria crinita (Leguminosae). The structure of 1 was elucidated by detailed spectroscopic means including IR, HR-ESI-MS, 1D and 2D NMR, and CD data. Compounds 1-9 were evaluated for their cytotoxicity against four human cancer cell lines KB (mouth epidermal carcinoma), HepG2 (hepatocellular carcinoma), Lu (lung carcinoma) and MCF7 (breast carcinoma). Compound 1 showed cytotoxic activity against the tested cell lines with IC 50 values of 33.2, 29.4, 59.6 and 66.8 μM, respectively.

This indicates that 20HE significantly decreases the number of cells in the G/S phase of the cell cycle in human AML cells. This is the first time that the anti-proliferative activity of 20HE against a human tumor cell line has been reported.

The diterpene isocoronarin D (1) is a bioactive major constituent of labdane diterpene from the aerial parts of Curcuma comosa Roxb. (Zingiberaceae), the Thai medicinal plant.Microbial transformation of 1 was performed by the fungus Cunninghamella echinulata NRRL 1386 to yield three new metabolites, 3-hydroxyisocoronarin D (2), 6hydroxyisocoronarin D (3) and 3,7-dihydroxyisocoronarin D (4). The structures of the new compounds were elucidated by spectroscopic techniques.