ザイボックス^®錠を粉砕して製した懸濁液の安定性に関する検討

抄録

Zyvox^® (linezolid), an oxazolidinone-class synthetic antibacterial agent, has been approved for the treatment of vancomycin-resistant Enterococcus faecium infections. Although there are three forms of this drug, including injection, tablets and oral suspension, presently available overseas, only injection and tablets have so far been approved in Japan. It is possible to use ground tablets as an oral suspension. However, the quality including the stability of linezolid in such a suspension has not yet been studied. In this study, we therefore, examined the stability of linezolid in a suspension of ground tablets and the characteristics of such a suspension. The solubility of linezolid was low, and approximately 85% of linezolid was suspended in a solid phase. Linezolid was stable in the suspension, and there were no differences in the pH for up to 24 hours. However, precipitation occurred rapidly after the ground tablets had been suspended. The concentration of linezolid in the upper layer of the suspension decreased to half of the initial concentration in 15 min.
In conclusion, Zyvox^® was found to be stable and therefore is considered suitable to be ground and used in an oral suspension. Such suspensions should be re-suspended just before use, especially when the suspension is pre-constituted.