Efficacy of a topical nasal decongestant in different formulations: the effect of viscosity.

Factors affecting the absorption of drugs through the nasal mucosa are increasingly being studied. Dosage form factors, i.e. the viscosity of the excipients, have been claimed to be of importance for enhanced nasal absorption due to prolongation of contact time between drug and mucosa. In the present study, a comparison was made of the effect of a local nasal sympathomimetic when administered intranasally in formulations with different viscosities. Volunteers received the test drugs as nasal sprays in a randomized cross-over design by a rhinomanometric technique, the effect of the drug being recorded for up to 5 h after administration. No significant differences in effects were observed when the test formulations were compared.