ABSTRACT
CONTEXT: The intranasal route is a promising route of administration for several emergency rescue drugs including naloxone and glucagon. Glucagon nasal powder (GNP) is a novel, needle-free delivery system for intranasal administration of glucagon for the treatment of severe hypoglycemia, an infrequent but serious complication of insulin use in patients with diabetes. The GNP delivery device is a compact, highly portable, single-use nasal powder dosing device constructed of polypropylene that allows for simple, single-step administration. OBJECTIVE: To evaluate the toxicological profile of the polypropylene resin used in the actuator part of the delivery device that will contact skin and nasal mucosal membranes of the patient, we performed an in vitro cytotoxicity study, a skin sensitization study and an irritation (intracutaneous reactivity) study in animal models. METHODS: Extracts of the actuator of the GNP device were generated from HAM F12 medium with 10% fetal bovine serum, 0.9% sodium chloride (NaCl) or sesame oil. The in vitro cytotoxicity test was performed in cultured L929 mouse fibroblasts. Skin sensitization analysis was performed in 10 guinea pigs according to the Magnusson-Kligman method, using a maximization method with Freund's Complete Adjuvant. Irritation following intracutaneous/intradermal treatment with device extracts (NaCl and sesame oil extractants) was assessed in three New Zealand White rabbits. RESULTS: In vitro cytotoxicity test: Both undiluted and diluted extract showed no toxicity (i.e. no abnormal morphology, cell death or cell lysis) toward L929 fibroblasts (cytotoxicity grade 0). Sensitization test in guinea pigs: Challenge with device extracts did not evoke positive responses in test animals previously induced with device extracts. The net response value represented an incidence rate of 0% and a net dermal irritation score value of 0.00. Irritation (intracutaneous/intradermal) test in New Zealand White rabbits: Device extracts and corresponding vehicle controls caused similar irritation reactions. The difference between the mean scores for the device extracts and the corresponding vehicle controls was less than 1.0. CONCLUSIONS: Extracts of the polypropylene resin of the GNP delivery device are not cytotoxic, do not result in dermal sensitization and do not cause irritation when applied topically or intracutaneously. Given the infrequent use and very short duration of exposure to the nasal mucosa during administration of GNP, the polypropylene resin of the GNP device actuator will likely not cause adverse dermal sensitization effects or irritation effects in humans and can, therefore, be considered for use as a delivery device in clinical trials assessing the efficacy and safety of GNP for the treatment of insulin-using patients experiencing episodes of severe hypoglycemia.
