Freeze-drying of squalenoylated nucleoside analogue nanoparticles

• Published in: International journal of pharmaceutics 2009-11, Vol.381 (2), p.140-145
• Main Authors: Bildstein, L., Hillaireau, H., Desmaële, D., Lepêtre-Mouelhi, S., Dubernet, C., Couvreur, P.
• Format: Article
• Language: English
• Subjects: Algorithms; Animals; Antimetabolites - chemistry; Antimetabolites - pharmacology; Cell Line; Cell Survival - drug effects; Cold Temperature; Colloids; Cryoprotective Agents - chemistry; Deoxycytidine - analogs & derivatives; Deoxycytidine - chemistry; Deoxycytidine - pharmacology; Dideoxynucleosides - chemistry; Dideoxynucleosides - pharmacology; Drug Stability; Freeze Drying - methods; Freeze-drying; Inhibitory Concentration 50; Mice; Nanoparticles; Nanoparticles - administration & dosage; Nanoparticles - chemistry; Nephelometry and Turbidimetry; Nucleoside analogues; Nucleosides - chemistry; Nucleosides - pharmacology; Prodrugs - chemistry; Prodrugs - pharmacology; Squalene; Squalene - analogs & derivatives; Squalene - chemistry; Squalene - pharmacology; Stability; Surface Properties; Time Factors; Trehalose - chemistry
• ISSN: 0378-5173; 1873-3476
• DOI: 10.1016/j.ijpharm.2009.04.002

Nucleoside analogues are potent anticancer or antiviral agents that however display some limitations (rapid metabolism, induction of resistance). In order to overcome these drawbacks, we recently proposed new prodrugs, in which nucleoside analogues were covalently coupled to squalene (SQ). The resulting amphiphilic compounds spontaneously formed nanoparticles (NPs) and displayed a promising efficacy both in vitro and in vivo. Since long-term stability is essential for further clinical development we needed to develop a laboratory-scale freeze-drying protocol in order to improve the colloidal stability of those NPs. Squalenoylated gemcitabine (SQdFdC) has been successfully freeze-dried with trehalose (10%, w/w) as a cryoprotectant. Concentrations of SQdFdC up to 4 mg/mL after freeze-drying and rehydration have been obtained, which is necessary for in vivo studies. Stability measurements by dynamic light scattering showed that trehalose had a stabilizing effect on SQdFdC NPs, and that freeze-dried SQdFdC NPs could be stored up to four months at room temperature before rehydration, without loss of stability. In vitro cytotoxicity studies on three murine cell lines showed that SQdFdC NPs retained their cytotoxic activity after freeze-drying. We showed that this freeze-drying protocol could also be applied to squalenoylated didanosine (SQddI) and zalcitabine (SQddC). Overall, these results allow for the use of freeze-dried NPs in upcoming preclinical trials of the different squalenoylated compounds developed in our laboratory.