Artesunate (AST), the most widely used artemisnin derivative, has poor aqueous solubility and suffers from low oral bioavailability (~40%). Under these conditions, nanoparticles with controlled and sustained released properties can be a suitable solution for improving its biopharmaceuticals properties. This work reports the preparation and characterization of auto-assembled chitosan/lecithin nanoparticles loaded with AST and AST complexed with β-cyclodextrin (β-CD) to boost its antimalarial activity. The nanoparticles prepared by direct injection of lecithin alcoholic solution into chitosan/water solution have shown the particle size distribution below 300 nm. Drug entrapment efficiency was found to be maximum (90%) for nanoparticles containing 100 mg of AST. Transmission electron microscopy images show spherical shape with contrasted corona (chitosan) surrounded by a lipidic core (lecithin + isopropyl myristate). Differential scanning calorimeter thermograms demonstrated the presence of drug in drug-loaded nanoparticles along with the disappearance of decomposition exotherm suggesting the increased physical stability of drug in prepared formulations. Negligible changes in the characteristic peaks of drug in Fourier-transform infrared spectra indicated the absence of any interaction among the various components entrapped in the nanoparticle formulation. In vitro drug release behavior was found to be influenced by pH value. Increased in vivo antimalarial activity in terms of less mean percent parasitemia was observed in infected Plasmodium berghei mice after the oral administration of all the prepared nanoparticle formulations.

The present study investigates the structural and pharmaceutical properties of different multicomponent crystalline forms of lamotrigine (LTG) with some pharmaceutically acceptable coformers viz.nicotinamide (1), acetamide (2), acetic acid (3), 4-hydroxy-benzoic acid (4) and saccharin (5). The structurally homogeneous phases were characterized in the solid state by DSC/TGA, FT-IR and XRD (powder and single crystal structure analysis) as well as in the solution phase. Forms 1 and 2 were found to be cocrystal hydrate and cocrystal, respectively, while in forms 3, 4 and 5, proton transfer was observed from coformer to drug. The enthalpy of formation of multicomponent crystals from their components was determined from the enthalpy of solution of the cocrystals and the components separately. Higher exothermic values of the enthalpy of formation for molecular complexes 3, 4 and 5 suggest these to be more stable than 1 and 2. The solubility was measured in water as well as in phosphate buffers of varying pH. The salt solvate 3 exhibited the highest solubility of the drug in water as well as in buffers over the pH range 7–3 while the cocrystal hydrate 1 showed the maximum solubility in a buffer of pH 2. A significant lowering of the dosage profile of LTG was observed for 1, 3 and 5 in the animal activity studies on mice.

The present study reports novel cocrystals of telmisartan (TEL) with saccharin and glutaric acid. Crystal engineering approaches such as solution crystallization, solid-state grinding and slurry method have been utilized with the ultimate objective of improving the solubility of this BCS class II drug. The physical characterization revealed that the cocrystals are unique vis-à-vis thermal, spectroscopic and X-ray diffraction properties. Structural characterization showed that the cocrystals with saccharin and glutaric acid exist in monoclinic P2₁/c and triclinic P space groups, respectively. The improved solubility of telmisartan–saccharin (TEL–SAC) (nine-fold) and telmisartan–glutaric acid (two-fold) cocrystals in comparison with the free drug has been demonstrated in solubility experiments in phosphate buffer, pH 7.5. The TEL–SAC cocrystal remained stable in the aqueous medium for 6 hours as confirmed by PXRD. The AUC_0–24 of TEL–SAC and TEL–GA was found to be 2-fold and 1.4-fold increased in terms of bioavailability than pure TEL, respectively. The in vivo antihypertensive activity of TEL–SAC in DOCA salt-induced hypertensive rats showed two-fold improved efficacy, while acute toxicity studies revealed no signs of toxicity in rats even at doses of 2000 mg kg⁻¹ of body weight (BW). The new solid phase of telmisartan with saccharin represents a promising and viable opportunity for the manufacture of a drug product with improved therapeutic outcomes.