title: In vitro evaluation of the dissolution rate of crystalline suspensions destined to intramuscular administration.
abstract: The aqueous suspensions for intramuscular administration belong to the group of the dosage forms, that have a sustained release behaviour. These are based on the low aqueous solubility of the administered molecule whose aqueous suspensions form a depot in the muscular tissue which controls the absorption. The assays performed previously with two molecules of these characteristics have shown the inability of the habitual methods used for evaluating the dissolution rate of a drug, to determine the possible behaviour of these drugs in a definite and concrete formulation. For this reason, we have designed and developed a new method which allows us to support future processes, such as agglomeration and, possibly, cyst forming, that could be developed "in vivo". In this way, a more reliable prediction of the efficiency of inefficiency of this kind of formulation will be possible. Tha validity of our system has been studied with three formulations. Two of them were sustained release cefazolin molecules showing agglomeration problems "in vivo" and the other one a commercial penicillin-G benzathine commercial with a great efficacy demonstrated in habitual clinical practice.
authors.affiliation: Department of Pharmacy, Faculty of Pharmacy, University of Madrid, Spain.
authors.forename: R
authors.initials: R
authors.lastname: Cadorniga
authors.forename: M L
authors.initials: ML
authors.lastname: Burgos
authors.forename: S
authors.initials: S
authors.lastname: Negro
authors.forename: M T
authors.initials: MT
authors.lastname: Nernanez
authors.forename: P
authors.initials: P
authors.lastname: Pastoriza
authors.forename: I T
authors.initials: IT
authors.lastname: Molina
mesh_terms: D002437:Cefazolin / Q000737:chemistry / Q000493:pharmacokinetics; D003460:Crystallization; D003692:Delayed-Action Preparations; D007273:Injections, Intramuscular; D007700:Kinetics; D008954:Models, Biological; D010400:Penicillin G / Q000737:chemistry; D012995:Solubility; D013535:Suspensions / Q000737:chemistry*
chemical_list: D003692:Delayed-Action Preparations; D013535:Suspensions; D002437:Cefazolin; D010400:Penicillin G