Drug formulations, hyaluronan

IV. Drug Formulations Using Hyaiuronan A. Hyaluronan/Drug Admixtures in Oncology... 

Increasing the viscosity of solutions administered to the nasal cavity with, for example, methylcellulose, hyaluronan etc., has been shown to increase the time the formulation is retained in the nasal cavity and to enhance the absorption of certain drugs. It is thought that, up to an optimum viscosity, higher viscosity solutions give a more localized deposition in the anterior portion of the nose (i.e. low clearance site). As viscosity can affect droplet size by altering the surface tension of the solution, the more localized deposition in the anterior of the nose may be due to viscosity-related changes in the particle size of the delivered droplets. 

Research on nasal powder drug delivery has employed polymers such as starch, dextrans, polyacrylic acid derivatives (e.g., carbopol, polycarbophil), cellulose derivatives (microcrystalline cellulose, semicrystalline cellulose, hydroxypropylmethyl cellulose, hydroxypropyl cellulose, carboxymethyl cellulose), chitosan, sodium alginate, hyaluronans, and polyanhydrides such as poly(methyl vinyl ether-co-maleic anhydride) (PVM/MA). Many of these polymers have already been used as excipients in pharmaceutical formulations and are often referred to as first-generation bioadhesives [38-45], In nasal dry powder a single bioadhesive polymer or a... 

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