title: [Granulometric determination of the effect of polyvinylpyrrolidone on the dissolution rates of difficultyly soluble drugs (author's transl)].
abstract: The authors investigated the usability of the TUR ZG 2 gramulometer for determining the dissolution rates of difficultly soluble drugs (prednisolone, nitrofurantoin, nitrofural), especially under the influence of polyvinylpyrrolidone (PVP K 25 and PVP K 90), and for characterizing the changes in dispersity of PVP suspension gels. The dissolution gels of all three drugs were considerably increased by PVP (1--10%). Principally, PVP suspension gels of these drugs underwent changes in dispersity during storage (20 weeks), the particle numbers of prednisolone preparations being doubled. The particle numbers of the nitrofurantoin and nitrofural preparations decreased continuously, beginning with the second week of storage, which may be attributed to an improvement in solubility due to the use of the macromolecular adjuvant. PVP K 90 improved the solubilities of the drugs to a greater extent than PVP K 25.
mesh_terms: D002626:Chemistry, Pharmaceutical; D005782:Gels; D009582:Nitrofurantoin; D009583:Nitrofurazone; D010316:Particle Size; D011205:Povidone; D011239:Prednisolone; D012995:Solubility; D013535:Suspensions; D013997:Time Factors
chemical_list: D005782:Gels; D013535:Suspensions; D009582:Nitrofurantoin; D011239:Prednisolone; D011205:Povidone; D009583:Nitrofurazone
vernacular_title: Granulometrische Erfassung des Einflusses von Polyvinylpyrrolidon auf die Lösungsgeschwindigkeit schwerlöslicher Arzneistoffe.