PRELIMINARY INVESTIGATION INTO COMPARATIVE TRANSCRANIAL BRAIN TARGETED AND TRANSDERMAL SYSTEMIC EFFECTS OF DIAZEPAM ON SLEEP LATENCY

Walisinghe Pathirana*, Sudath Gunasekera, Godwin Constantine, Yashasvi Sanja Perera, Wedisha Gankanda, Malsha Gunathilaka, Sandamali Senanayake and Janaki Kumari

Emissary veins that drain blood from the scalp into sinuses of the brain are a potential route for targeted central nervous system drug delivery. Structure of the scalp, cranial bones and cerebrospinal fluid flow indicate that they can facilitate transcranial drug delivery. A cascade for the transcranial drug diffusion is proposed. Diazepam 2 mg/3 ml of sesame oil was administered transcranially and transdermally in order to investigate brain targeting in human volunteers. Sleep latencies were monitored with Multiple Sleep Latency Tests involving 5 Naps employing standard electroencephalography, electroocculography and electromyography electrodes. The six volunteers were subjected to four days of electroencephalography screenings for the base line, placebo oil, diazepam on scalp and diazepam on forearms. The mean sleep latencies for the Nap 3 with peak responses were 13.8, 8.7, 5.9 and 7.7 minutes respectively indicating that the transcranial brain targeting of diazepam is possible.