Oral Spray Delivery of Ondansetron Bioequivalent to Tablets

ATLANTA—Bioavailability studies show that oral spray delivery of the antiemetic 5-HT3 antagonist ondansetron is equivalent to oral delivery with ondansetron tablets (Zofran), Wayne Yates, MBA, and Greg Berk, MD, of Hana Biosciences, said at the American Society of Clinical Oncology 42nd Annual Meeting (abstract 8622). Hana Biosciences has submitted a New Drug Application to the FDA for the oral spray (brand name Zensana) for the prevention of nausea and vomiting associated with chemotherapy or radiotherapy, and the prevention of postoperatively induced nausea and vomiting.

Zensana achieves therapeutic drug levels by delivering small droplets of concentrated drug solution over the oral mucosa, Dr. Berk and his colleagues said at ASCO. The oral spray may offer advantages to patients requiring antiemetic therapy who have difficulty swallowing and holding down pills or who do not tolerate other oral forms, he said. In a recent survey of medical and radiation oncologists conducted by the Winokur Consulting Group, half of the respondents said they had patients who had some difficulty swallowing or holding down their full dose of antiemetic, whether a tablet or an oral disintegrating tablet, according to Hana Biosciences.

Dr. Berk reported results of two bioavailability studies in healthy adults: a randomized two-way crossover study comparing 8 mg Zensana to an 8-mg Zofran tablet, with treatments separated by 7 days, and a randomized 5-way crossover study comparing Zensana 4 mg, 8 mg, and 12 mg, to an 8-mg Zofran tablet, with treatments separated by 48 hours.

In both studies, Zensana 8 mg proved bioequivalent to an 8-mg Zofran tablet. Absorption studies showed that in the first 30 minutes after delivery, Zensana resulted in a greater number of subjects with initial detectable ondansetron concentrations (P<.05). The agent was well tolerated in single and multiple doses, Dr. Berk said.