Fabrication of composite microparticles of artemisinin for dissolution enhancement

Stabilizing Effect of Soluplus on Erlotinib Metastable Crystal Form in Microparticles and Amorphous Solid Dispersions

Microparticles (MPs) and amorphous solid dispersions (SDs) are effective methods to improve the dissolution of insoluble drugs. However, stability is a concern for these two high-energy systems, resulting from high surface area and amorphous polymorph, respectively. As an amphiphilic polymer, Soluplus (SOL) is usually used as a carrier in SDs. In this study, erlotinib microparticles (ERL MPs) and erlotinib solid dispersions (ERL SDs) were prepared with SOL by bottom-up technology and solvent evaporation. The solid-state properties of ERL MPs and ERL SDs were characterized by Differential Scanning Calorimetry (DSC), Powder X-Ray Diffraction (PXRD) and Scanning Electron Microscopy (SEM). The ERL MPs existed in a metastable crystal form A while the ERL SDs existed in an amorphous state. Fourier transform infrared spectroscopy (FT-IR) showed that there was a hydrogen bond interaction between the N-H group of ERL and the carbonyl group of SOL in ERL MPs and SDs. The dissolution profiles of ERL SDs and ERL MPs were improved significantly. ERL MPs showed better stability than ERL SDs in accelerated stability test. The discrepant stabilizing effects of polymer SOL in two systems may provide effective ideas for solubilization of insoluble drugs and the stability of drugs after recrystallization.

Electrospun Nanofibers of Polycaprolactone/Collagen as a Sustained-Release Drug Delivery System for Artemisinin

The application of artemisinin (ART) in the treatment of malaria has been restricted to a certain degree due to its inherent limitations, such as short half-life, poor solubility, limited bioavailability, and re-crystallization. Electrospun nanofibers loaded with ART provide an excellent solution to these limitations and yield sustained drug release as well as inhibition of drug re-crystallization. In this study, ART-loaded polycaprolactone (PCL)/collagen (Col) nanofibers with different proportions of polymers were prepared. ART-loaded PCL/Col nanofibers were characterized, and further ART anti-crystallization and release behaviors were studied. SEM was used to observe the morphology of PCL/Col nanofibers. X-ray diffraction (XRD) was used to characterize the physical state of ART in ART-loaded PCL/Col nanofibers. Fourier transform infrared spectroscopy (FTIR), water contact angle measurement, weight loss, degree of swelling, and drug release experiments can verify the differences in performance of ART-loaded PCL/Col nanofibers due to different polymer ratios. The release curve was analyzed by kinetics, showing sustained release for up to 48 h, and followed the Fickian release mechanism, which was shown by the diffusion index value obtained from the Korsmeyer-Peppas equation.

Dissolution and physicochemical stability enhancement of artemisinin and mefloquine co-formulation via nano-confinement with mesoporous SBA-15

The objective of this study is to enhance the dissolution rate, supersaturation and physicochemical stability of combination of two poorly water-soluble anti-malarial drugs, artemisinin (ART) and mefloquine (MFQ), by encapsulating them inside mesoporous silica (SBA-15) via co-spray drying. Characteristic studies such as powder X-ray diffraction (PXRD), transmission electron microscopy (TEM) and scanning electron microscope (SEM) clearly indicate the amorphization of the crystalline drugs. ART/MQF/SBA-15 formulations show a superior dissolution enhancement with a burst release of more than 95% of drugs within 30min. In addition, the combination formulation exhibits a stable supersaturation enhancement by 2-fold higher than that of the untreated crystalline counterparts. ART/MQF/SBA-15 samples possess excellent physicochemical stability under 2 different moderate storage conditions for 6 months. The amorphization of ART and MFQ via nano-confinement using mesoporous SBA-15 is a potentially promising approach to enhance the solubility of poorly water-soluble anti-malarial drugs that co-formulated into a single dosage form.

Enhanced dissolution and stability of artemisinin by nano-confinement in ordered mesoporous SBA-15 particles

Dissolution of poorly water-soluble drug, Artemisinin (ART), was enhanced by encapsulating the drug particles inside pore channels of ordered mesoporous silica, SBA-15, via co-spray drying. The drug release profiles of ART were investigated by using flow-through cell (USP IV) and in vitro dissolution tester (USP II). The co-spray-dried ART/SBA-15 samples demonstrated significantly improved dissolution rates and supersaturation compared to the untreated ART. The low cytotoxicity effect of ART and SBA-15 on Caco-2 cells after 24 h incubation demonstrated the biocompatibility of ART/SBA-15. Finally, the storage stability of the samples was investigated for 6 months under five different storage conditions. Overall, the solid dispersions exhibited excellent physical stability; however, their chemical stability was affected by humidity regardless of storage temperatures. The formulation of solid dispersions of ART/SBA-15 is potentially safe and an effective approach to enhance the solubility of poorly water-soluble ART.

β-Cyclodextrin polymer nanoparticles as carriers for doxorubicin and artemisinin: a spectroscopic and photophysical study

The association of doxorubicin (DOX) and artemisinin (ART) to a β-CyD-epichlorohydrin crosslinked polymer (pβ-CyD), organized in nanoparticles of ca. 15 nm size, was investigated in neutral aqueous medium by circular dichroism (CD), UV-vis absorption and fluorescence. The stability constants and the absolute CD spectra of the drug complexes were determined by global analysis of multiwavelength data from spectroscopic titrations. The polymer pβ-CyD proved able to disrupt the DOX dimer when the latter is the predominant form of DOX in solution. The spectroscopic and photophysical properties of the complexes evidenced an alcohol-like environment for ART and an improved inherent emission ability for DOX in the nanoparticle frame.