Smal J, Haapala O, Marvola M, Kuusela S, Happonen I
Department of Pharmacy, University of Helsinki, Finland.
J Vet Pharmacol Ther. 1995 Feb;18(1):17-23. doi: 10.1111/j.1365-2885.1995.tb00545.x.
The object of this study was to examine whether prolonged-release hard gelatin capsule formulations could be developed for dogs. Different viscosity grades of hydroxypropyl methylcellulose (HPMC) and sodium carboxymethylcellulose (NaCMC) were used to control drug release. Furosemide was chosen because of its wide use in the management of heart failure in dogs. In vitro, selecting different viscosity grades allowed good control of drug release, whereas in vivo the difference between formulations was clearly smaller. Although all formulations gave prolonged release, both inter- and intra-individual variation in the plasma concentration-time curves was high. It is difficult to develop prolonged-release formulations for drugs such as furosemide with highly variable pharmacokinetic properties. However, hard gelatin capsules containing hydrophilic polymers could still be a suitable choice for some drugs.
本研究的目的是考察是否可以开发出适用于犬的缓释硬明胶胶囊制剂。使用不同粘度等级的羟丙基甲基纤维素（HPMC）和羧甲基纤维素钠（NaCMC）来控制药物释放。选择速尿是因为其在犬心力衰竭治疗中广泛应用。在体外，选择不同粘度等级可很好地控制药物释放，而在体内，制剂之间的差异明显较小。尽管所有制剂均实现了缓释，但血浆浓度-时间曲线的个体间和个体内差异都很大。对于像速尿这种药代动力学性质高度可变的药物，开发缓释制剂很困难。然而，含有亲水性聚合物的硬明胶胶囊对某些药物而言仍可能是合适的选择。
