Two new trans-clerodane diterpenoids from Otostegia limbata

Two new tricyclic clerodane-type diterpenoids, limbatolide D (1) and limbatolide E (2), have been isolated from the roots of Otostegia limbata. Their structures and the relative configuration were established on the basis of spectral methods, especially two-dimensional (2D) NMR techniques.

Optimization of process parameters by response surface methodology to develop a more bioefficacious nanosuspension of Silybum marianum seed extract

Purpose: To develop a nanosuspension drug delivery system to enhance the dissolution rate of Silybum marianum seeds extract. Methods: Central composite design was used to study the effect of the input variables (stabilizer to plant extract ratio, antisolvent to solvent ratio, stirring time) on the dependent variables (mean particle size, polydispersity index (PDI) and zeta potential). The optimized formulation was characterized by Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), Fourier Transformed Infrared Microscopy (FT-IR) and in vitro dissolution testing. Results: The optimized nanosuspension with mean particle size of 137 nm, PDI of 0.327 and zeta potential of -37 mV was obtained. SEM studies revealed irregular shaped particles. AFM studies showed nanosized particles with good surface characteristics. The optimized formulation showed faster dissolution rate than coarse suspension. Conclusion: Results suggested that nanosuspension has remarkable potential for enhancement of the dissolution properties of poorly soluble S. marianum seed extract. Keywords: Silybum marianum; Nanosuspension; Optimization; Dissolution rate

Development of Nanosuspension of Artemisia absinthium Extract as Novel Drug Delivery System to Enhance Its Bioavailability and Hepatoprotective Potential

A nanosuspension of Artemisia absinthium extract was formulated and characterized for the enhancement of bioavailability and better hepatoprotective efficacy. The nanosuspension of A. absinthium extract was formulated using an antisolvent precipitation technique, and various formulation parameters were optimized using response surface methodology (RSM). The optimized nanosuspension was characterized using AFM and FT-IR spectroscopy. The drug-release profile and oral bioavailability of the optimized nanosuspension were assessed with reference to coarse suspension. The DPPH radical scavenging method was used to measure the nanosuspension's antioxidant activity, and its in vivo hepatoprotective potential was assessed against CCl4-induced hepatic injury in rats. The developed optimized nanosuspension had suitable zeta potential of -11.9 mV, PDI of 0.285, and mean particle size of 253.8 nm. AFM study demonstrated a homogeneous population of nanoparticles with average size of 25 nm. The formulated nanosuspension of A. absinthium showed faster dissolution rate and 1.13-fold enhanced bioavailability as compared to the coarse suspension (plant extract). Furthermore, the nanoformulation had stronger antioxidant and hepatoprotective potential as compared to the unprocessed coarse extract. These results demonstrated that nanosuspension is a promising strategy for improving the oral bioavailability and bioactivities of A. absinthium extract.