In an upcoming in vivo experiment, we will be administering enzalutamide by i.p. injection in nude mice. We plan to dissolve Enzalutamide in DMSO, and then dilute this solution using normal saline such that the resultant concentration of DMSO is 10%. I have observed that when normal saline is added, a fine suspension forms. Has anyone experienced this before? Does anyone have any opinions about injecting suspensions by the i.p. route? If I heat this suspension to 60-70°C, a clear solution results (which remains solution after cooling), but could this affect the compound's stability and is there any real need for this? If anyone has any advice for me, I'd be most appreciative. Thank you kindly.
the marketed oral formulation in soft gelatine capsules contains Labrasol as emulsifier. You may add this or Tween 80. Maybe this helps.
I am not sure that the suspension will have an impact on bioavailability, but it will almost certainly have an impact on pharmacokinetics in the same way as insulin.
I would therefore recommend that you use another solubilisation technique than cosolvation with DMSO.
Maybe this article will help you :Article Effect of polymers and cyclodextrins on solubility, permeabi...
Regarding the use of cyclodextrins I would tell you to try gamma-cyclodextrin or HP-gamma-CD rather than beta-CD derivatives as its bigger cavity may ease complex formation.
Regards,