Opportunity and challenges of nasal powders: Drug formulation and delivery

Abstract

In the field of nasal drug delivery, among the preparations defined by the European Pharmacopoeia, nasal powders facilitate the formulation of poorly water-soluble active compounds. They often display a simple composition in excipients (if any), allow for the administration of larger drug doses and enhance drug diffusion and absorption across the mucosa, improving bioavailability compared to nasal liquids. Despite the positive features, however, nasal products in this form still struggle to enter the market: the few available on the market are Onzetra Xsail® (sumatriptan) for migraine relief and, for the treatment of rhinitis, Rhinocort® Turbuhaler® (budesonide), Teijin Rhinocort® (beclomethasone dipropionate) and Erizas® (dexamethasone cipecilate). Hence, this review tries to understand why nasal powder formulations are still less common than liquid ones by analyzing whether this depends on the lack of (i) real evidence of superior therapeutic benefit of powders, (ii) therapeutic and/or commercial interest, (iii) efficient manufacturing methods or (iv) availability of suitable and affordable delivery devices. To this purpose, the reader's attention will be guided through nasal powder formulation strategies and manufacturing techniques, eventually giving up-to-date evidences of therapeutic efficacy in vivo. Advancements in the technology of insufflation devices will also be provided as nasal drug products are typical drug-device combinations.

In vivo nose-to-brain delivery of the hydrophilic antiviral ribavirin by microparticle agglomerates

“…Despite the field of nasal delivery is dominated by liquid sprays, the use of dry powder formulations appears appealing for innovative products, in particular those designed for a nose-to-brain delivery (Tiozzo Fasiolo et al., 2018 ). In fact, dry powder formulations are providing several advantages over liquids such as chemical stability, absence of preservatives, higher unit dosages per administration, longer residence time and contact with the nasal mucosa and eventually improved bioavailability (Pozzoli et al., 2016 ).…”

Investigation of the Absorption of Nanosized lamotrigine Containing Nasal Powder via the Nasal Cavity

“…The particle size of LAM and the samples is shown in Table 1. The acceptable range that is required for nasal powders is between 5 and 45 µm [31]. The raw, crystalline LAM particles were in this acceptable, micrometric range, but they were aggregated, which could make the application of the API uncertain.…”

“…Nasal powder formulations have better physicochemical and microbiological stability over liquid formulations [28][29][30]. Thus, preservatives are not necessary, their shelf-life is longer, transportation is easier and packaging is more economical compared to liquid formulations [31]. By applying powder formulations, higher administration dose and better adhesion to the nasal mucosa can be achieved, that may cause better absorption through the barrier [32,33].…”

Recent Approaches for Solid Dose Vaccine Delivery

“…It is recommended to store the dry-powder inhaler under 40%-45% relative humidity [81]. Since most of the developing countries have higher relative humidity, it is crucial to take this factor into consideration during the formulation and packaging of the dry-powder vaccine formulation [82].…”