Retno Sari

Development of Andrographolide-Carboxymethyl Chitosan Nanoparticles: Characterization, in vitro Release and in vivo Antimalarial Activity Study

Objectives: The purpose of this study was to investigate the effect of andrographolide-carboxymethyl chitosan nanoparticles formation on the physical characteristics, in vitro release profile and in vivo antimalarial activity of andrographolide. Materials and Methods: Nanoparticles were prepared by ionic gelation method-spray drying using CaCl2 as the crosslinker with a composition of drug: polymer: CaCl2=40: 250: 100. The obtained particles were evaluated for its size and morphology; physical state, drug content, in vitro drug release and in vivo antimalarial activity on Plasmodium berghei infected mice. Results: The results of DTA and XRD showed that nanoparticle systems had a lower melting point and lower crystallinity degree. The drug dissolved from the nanoparticles was increased up to 6.5 times and the in vivo antimalarial activity was 1.65 times higher compared to andrographolide. Conclusion: The formation andrographolide-carboxymethyl chitosan nanoparticles affected the physical characte-ristics of andrographolide. The decrease crystallinity of andrographolide resulted in a lower melting point of andrographolide. Such changes provided a positive impact to the drug dissolution and then its activity.

Physicochemical Characterization and In Vitro Dissolution Test of Quercetin-Succinic Acid Co-crystals Prepared Using Solvent Evaporation

Objectives: Quercetin is one of the flavonoids with a polyhydroxyaromatic structure. Quercetin has been proposed to exhibit a bioWactivity against oxidative stress. However, quercetin has poor solubility in aqueous media. The purpose of this study was to investigate the physicochemical properties and dissolution rates of quercetin-succinic acid co-crystals. Materials and Methods: The quercetin-succinic acid co-crystals were prepared in 1:1 molar ratio using solvent evaporation. X-ray diffraction, differential thermal analysis, infrared spectroscopy, and scanning electron microscopy were performed to determine the physicochemical properties of quercetin-succinic acid co-crystals. Dissolution was studied in medium citrate buffer with 2% SLS for 60 min using USP II (paddle) apparatus at 100 rpm and 37°C. Results: Based on diffractogram, thermogram, infrared spectrum, and microscopic capture, the physicochemical properties of quercetin-succinic acid co-crystals showed difference to those of quercetin. In addition, the in vitro dissolution test showed that the dissolution profile of co-crystals was significantly higher than pure quercetin. Conclusion: This study suggests that the formation of quercetin-succinic acid co-crystals using solvent evaporation enhanced the physicochemical properties and dissolution rate of quercetin.