Formulation of 99mTechnetium-labeled leuprolide loaded liposomes and its biodistribution study in New Zealand white female rabbits for assessment of its uterine targeting efficiency

Nuclear imaging of liposomal drug delivery systems: A critical review of radiolabelling methods and applications in nanomedicine

The integration of nuclear imaging with nanomedicine is a powerful tool for efficient development and clinical translation of liposomal drug delivery systems. Furthermore, it may allow highly efficient imaging-guided personalised treatments. In this article, we critically review methods available for radiolabelling liposomes. We discuss the influence that the radiolabelling methods can have on their biodistribution and highlight the often-overlooked possibility of misinterpretation of results due to decomposition in vivo. We stress the need for knowing the biodistribution/pharmacokinetics of both the radiolabelled liposomal components and free radionuclides in order to confidently evaluate the images, as they often share excretion pathways with intact liposomes (e.g. phospholipids, metallic radionuclides) and even show significant tumour uptake by themselves (e.g. some radionuclides). Finally, we describe preclinical and clinical studies using radiolabelled liposomes and discuss their impact in supporting liposomal drug development and clinical translation in several diseases, including personalised nanomedicine approaches.

Lyophilized tablets for focal delivery of fluconazole and itraconazole through vaginal mucosa, rational design and in vitro evaluation

The present work deals with the rational design and in vitro evaluation of vaginal tablets for focal delivery of fluconazole (FLZ) and itraconazol (ITZ). Drug loaded liposomes with and without d-alpha-tocopheryl polyethylene glycol 1000 succinate (vit E TPGS) were prepared by direct sonication of the components and mixed with albumin to obtain albusomes. Tablets were obtained by direct compression of the lyophilized cake. The influence of vit E TPGS on size, zeta potential and entrapment efficiency (EE%) of liposomes and albusomes was evaluated. Tablet swelling and drug release were studied by in vitro assays. Vit E TPGS neither affected the zeta potential nor the EE% of liposomes and albusomes, but affected the liposomes size and the tablet disintegration time. A rapid erosion was observed for the tablets with the highest content of vitamin, while a slow swelling for those lacking the vitamin (swelling index = 57.76 ± 13.51%). A faster drug release profile was obtained for the former compared to the latter. The in vitro assay showed that FLZ diffused and solved in the vaginal fluid simulant while ITZ remained into the albusomes, which slowly released ITZ-albumin complex and ITZ-loaded liposomes, both suitable carriers for drug transport to deeper vaginal endothelium.