Histopathological evaluation of insulin-DMSO formula designed for direct nose-to-brain delivery

The combination of insulin and DMSO is a patented (Publication No US8987199B2), noninvasive, pharmaceutically strategized preparation for direct nose-to-brain delivery (DN2BD) suggested for the treatment of Alzheimer's disease (AD). Although its main ingredients have been individually researched, no histopathological investigations have been conducted to address this combination effect on the CNS and nasal tissues in animals. The present work was, therefore, designed to investigate the potential histopathological changes induced by this new pharmaceutical combination using a newly developed refractory staining method. The findings presented herein showed no signs of treatment-related lesions or behavioral changes in Sprague Dawley rats following a three-month successive treatment with two strengths of the formula.