THE EFFECT OF NASAL DRUG FORMULATIONS ON CILIARY BEATING IN-VITRO

In order to estimate the potential of nasal drug formulations to influ ence ciliary beating, ciliary beat frequency (CBF) measurements were p erformed in vitro, using chicken embryo trachea and a photo-electric r egistration device. The effects of nasal prescription and non-prescrip tion drug formulations were studied and compared with a number of inve stigational nasal drug formulations containing estradiol, dihydroergot amine mesylate and salmon calcitonin. The influence of all formulation s on CBF was related to the effects of formulation additives such as p reservatives and nasal absorption enhancers on the ciliated tissue. Fo r almost all nasal drug formulations, the preservatives used in the fo rmulations (e.g. benzalkonium chloride, chlorobutanol) play a decisive role in the observed ciliostatic effects. Methylated beta-cyclodextri ns, used as nasal absorption enhancers/solubilizers in the investigati onal formulations, appeared to be relatively non-toxic for the ciliate d tissue, having similar effects on CBF as physiological saline. After dilution five times, most drug formulations studied showed a moderate ciliostatic effect, but marked differences could still be detected. T he present study demonstrates that CBF measurements in vitro are a val uable tool in the design of safe nasal drug formulations.