Laboratory Testing Blog

New 11 Page Whitepaper: Predicting Nasal Drug Absorption With In Vitro Release Testing

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Drugs have been administered nasally for therapeutic and recreational purposes since ancient times.  Psychotropic drugs and hallucinogens were snuffed for these purposes by the South American Indians, and this practice is currently widespread among abusers of cocaine and heroin.

In general, among the primary targets for intranasal administration are pharmacologically active compounds with poor stability in gastrointestinal fluids, poor intestinal absorption and/or extensive hepatic first-pass elimination such as peptides, proteins and polar drugs.  Nasal delivery seems to be a favorable way to circumvent the obstacles for blood-brain barrier allowing the direct drug delivery in the biophase of central nervous system active compounds.

Therefore, nasal delivery is a feasible alternative to oral or parenteral administration for some drugs because of the high permeability of the nasal epithelium, rapid drug absorption across this membrane and avoidance of hepatic first-pass metabolism.  The widespread interest in an intranasal route for therapeutic purposes other than the topically nasal drug delivery arises from the particular anatomical, physiological and histological characteristics of the nasal cavity which provides potential for rapid systemic drug absorption and quick onset of action. In addition, intranasal absorption avoids the gastrointestinal and hepatic pre-systemic metabolism enhancing drug bioavailability in comparison with that obtained after gastrointestinal absorption.

Intranasal administration of medicines is the natural choice for the treatment of topical nasal disorders. Among the most common examples are antihistamines and corticosteroids for rhinosinusitis and nasal decongestants for cold symptoms.  In these cases, an intranasal route is the primary option for drug delivery because it allows rapid symptomatic relief with a more favorable adverse-event profile than oral or parenteral routes of administration.  In fact, relatively low doses are effective when administered topically, minimizing simultaneously the potential of systemic toxic effects.  Recently for instance, topical anti-biotherapy has been considered in chronic rhinosinusitis in an attempt to eradicate biofilm bacteria that is often resistant to systemic treatment and still avoiding systemic toxicity.

Nasal delivery has been explored as a potential alternative route for drugs with poor bioavailability and for the delivery of bio-sensitive and high molecular weight (MW) compounds such as proteins, peptides, steroids and vaccines.

Over the last few years due to the understanding of the positive attributes and appropriate characteristics of the nasal cavity, the intranasal route of administration has been increasingly considered for drug delivery when developing new chemical entities or improving the therapeutic profile of existing drugs.  To assess the therapeutic viability of intranasal drug delivery, several approaches should be considered, attending specifically to the acute or chronic nature of pathologic conditions and intended effects of drug treatment, whether local, systemic or into the central nervous system.

Dr. Theo Kapanadze has published a new whitepaper that will help you learn: