Formation of particles in aqueous infusions of the medical plant Harungana madagascariensis
Gröning, R.; Adesina, S.; Müller, R.S.
Die Pharmazie 59(4): 279-281
2004
ISSN/ISBN: 0031-7144 PMID: 15125572 Document Number: 568366
In some aqueous plant extracts, the formation of nanoparticles, microparticles and macroparticles has been observed. In the present investigation, the particle formation in aqueous infusions of H. madagascariensis, a medicinal plant, was investigated using photon correlation spectroscopy (PCS) and scanning electron microscopy (SEM). The nanoparticles with mean diameters of 220 nm were formed in aqueous infusions of the dried leaves of H. madagascariensis. The particles had an almost spherical shape. In aqueous infusions of the dried stem bark, nanoparticles with a mean diameter of 242 nm (PCS) were observed at 25 degrees C. The maximum particle size ranged from 200 nm to 300 nm. Nanoparticles were detected in infusions of the leaves and the bark from 25 degrees C to 55 degrees C. The mean diameter of the nanoparticles in preparations of the bark was temperature-dependent: at 55 degrees C, the mean diameter was 144 nm, whereas at 30 and 25 degrees C, the mean diameters were 197 and 242 nm, respectively. Lower temperatures resulted in higher count rates. In infusions of the leaves, the mean diameters varied between 220 (25 degrees C) and 139 nm (55 degrees C). Particle formation was investigated at pH 2.2, 4.0 and 7.4 at 37 degrees C. Nanoparticles were detected in infusions of the leaves and the stem bark at each pH. The pH value had an effect on mean diameter and count rate.