HO-1-u-1 model for screening sublingual drug delivery--influence of pH, osmolarity and permeation enhancer.

HO-1-u-1 (Ueda-1) is a human tumor cell line established from human sublingual squamous cell carcinoma. In previous study, HO-1-u-1 cell line was grown on cell culture inserts and utilized as in vitro model for screening sublingual drug delivery. The aim of current study was to further investigate the effects of pH, osmolarity and permeation enhancer, sodium glycodeoxycholate (GDC) on the permeability of three beta-blockers with different lipophilicities. The cytotoxicity was evaluated by MTS/PES assay. The permeability studies were carried out using the cell culture model and compared with that obtained from fresh porcine sublingual mucosa. The results showed the enhancement effects caused by pH, osmolarity and GDC were highly lipophilicity-dependent and in the order atenolol>metoprolol>propranolol. The apparent permeability coefficients (P(app)) of all the three beta-blockers were significantly increased by increasing pH. However, less enhancing effects were observed by non-physiological osmolarity or the presence of GDC in permeability study using both cell culture and porcine sublingual mucosa. The present results suggested that the HO-1-u-1 cell culture model maybe a useful and effective in vitro model for evaluating the enhancement effects and mechanism in sublingual drug delivery.