Avtor/Urednik		Kerč, J; Srčič, S; Planinšek, O; Kofler, B
Naslov		Contact angles and surface free energy parameters of some 1,4-dihydropyridine calcium antagonist powders
Tip		članek
Vir		Farm Vestn
Vol. in št.		Letnik 45, št. 4
Leto izdaje		1994
Obseg		str. 347-57
Jezik		eng
Abstrakt		The contact angle was used as a measure of the wettability of a solid, and determinations were made on pharmaceutical powders by direct measurement of the angle formed by a drop of a liquid on the compacted powder of a drug substance. The investigated drug substances are analogs of the 1,4-dihydropyridine calcium antagonist group: nifedipine, nimodipine, felodipine, nicardipine HCl, and amlodipine benzenesulphonate. Various liquids including water, ethylene glycol, and 30 percent ethanol, were used to measure powder polar forces and powder dispersion forces whose sum is the powder free surface energy which may serve to predict the solubility and dissolution rate of the powder. The values of surface free energy of nifedipine, nimodipine and felodipine were found to be much lower comparing to those of nicardipine HCl and amlodipine benzenesulphonate. Moreover, powders with low free surface energy were found to have much lower solubility and dissolution rate.
Deskriptorji		DIHYDROPYRIDINES POWDERS SOLUBILITY WATER ETHYLENE GLYCOLS FELODIPINE NIMODIPINE NIFEDIPINE NICARDIPINE AMLODIPINE SURFACE TENSION