Midazolam nasal spray to treat intermittent, stereotypic episodes of frequent seizure activity: pharmacology and clinical role, a comprehensive review

Midazolam - A diazepam replacement for the management of nerve agent-induced seizures

A benzodiazepine, diazepam, has been the leading antidote for seizures caused by nerve agents, the most toxic chemical weapons of mass destruction, since the 1960s. However, its limitations have often brought questions about its usefulness. Extensive effort has been devoted into exploring alternatives, such as other benzodiazepines, anticholinergics, or glutamate antagonists. However, only few showed clear clinical benefit. The only two options to ultimately reach clinical milestones are Avizafone, a water-soluble prodrug of diazepam adopted by the French and UK armed forces, and intramuscular midazolam, adopted by the US Army. The recently FDA-approved new intramuscular application of midazolam brought several advantages, such as rapid onset of action, short duration with predictable pharmacokinetics, increased water solubility for aqueous injectable solutions, and prolonged storage stability. Herein, we discuss the pitfalls and prospects of using midazolam as a substitute in anticonvulsant therapy with a particular focus on military purposes in combat casualty care. We have also considered and discussed several other alternatives that are currently at the experimental level. Recent studies have shown the superiority of midazolam over other benzodiazepines in the medical management of poisoned casualties. While its use in emergency care is straightforward, the proper dose for soldiers under battlefield conditions is questionable due to its sedative effects.

Development of neffy, an Epinephrine Nasal Spray, for Severe Allergic Reactions

Epinephrine autoinjectors (EAIs) are used for the treatment of severe allergic reactions in a community setting; however, their utility is limited by low prescription fulfillment rates, failure to carry, and failure to use due to fear of needles. Given that delayed administration of epinephrine is associated with increased morbidity/mortality, there has been a growing interest in developing needle-free, easy-to-use delivery devices. neffy (epinephrine nasal spray) consists of three Food and Drug Administration (FDA)-approved components: epinephrine, Intravail A3 (absorption enhancer), and a Unit Dose Spray (UDS). neffy's development pathway was established in conjunction with the FDA and the European Medicines Agency and included multiple clinical trials to evaluate pharmacokinetic and pharmacodynamic responses under a variety of conditions, such as self-administration and allergic and infectious rhinitis, as well as an animal anaphylaxis model of severe hypotension, where neffy demonstrated a pharmacokinetic profile that is within the range of approved injection products and a pharmacodynamic response that is as good or better than injections. The increased pulse rate (PR) and blood pressure (BP) observed even one minute following the administration of neffy confirm the activation of α and β adrenergic receptors, which are the key components of epinephrine's mechanism of action. The results suggest that neffy will provide a safe and effective needle-free option for the treatment of severe allergic reactions, including anaphylaxis.

Nose-to-brain drug delivery for the treatment of CNS disease: New development and strategies

Delivering drugs to the brain has always been a challenging task due to the restrictive properties of the blood-brain barrier (BBB). Intranasal delivery is therefore emerging as an efficient method of administration, making it easy to self-administration and thus provides a non-invasive and painless alternative to oral and parenteral administration for delivering therapeutics to the central nervous system (CNS). Recently, drug formulations have been developed to further enhance this nose-to-brain transport, primarily using nanoparticles (NPs). Therefore, the purposes of this review are to highlight and describe the anatomical basis of nasal-brain pathway and provide an overview of drug formulations and current drugs for intranasal administration in CNS disease.

Intranasal Polymeric and Lipid-Based Nanocarriers for CNS Drug Delivery

Nanomedicine is currently focused on the design and development of nanocarriers that enhance drug delivery to the brain to address unmet clinical needs for treating neuropsychiatric disorders and neurological diseases. Polymer and lipid-based drug carriers are advantageous for delivery to the central nervous system (CNS) due to their safety profiles, drug-loading capacity, and controlled-release properties. Polymer and lipid-based nanoparticles (NPs) are reported to penetrate the blood–brain barrier (BBB) and have been extensively assessed in in vitro and animal models of glioblastoma, epilepsy, and neurodegenerative disease. Since approval by the Food and Drug Administration (FDA) of intranasal esketamine for treatment of major depressive disorder, intranasal administration has emerged as an attractive route to bypass the BBB for drug delivery to the CNS. NPs can be specifically designed for intranasal administration by tailoring their size and coating with mucoadhesive agents or other moieties that promote transport across the nasal mucosa. In this review, unique characteristics of polymeric and lipid-based nanocarriers desirable for drug delivery to the brain are explored in addition to their potential for drug repurposing for the treatment of CNS disorders. Progress in intranasal drug delivery using polymeric and lipid-based nanostructures for the development of treatments of various neurological diseases are also described.