Buccal iontophoretic delivery of atenolol center dot HCl employing a new in vitro three-chamber permeation cell

The present work showed that the iontophoretic approach was feasible to enh ance buccal drug delivery. A new in vitro horizontal three-chamber iontopho retic permeation cell has been developed to reflect the in vivo iontophoret ic drug delivery more closely, electrodes were positioned on the epithelial side in separate chambers. Iontophoretic delivery of atenolol . HCl across porcine buccal mucosa increased proportional to (a) increased initial dono r concentration in the range of 0.027 M to 0.10 M atenolol . HCl, (b) incre ased ''on time" of current on/off ratio valued 50/50, 75/25 and 90/10 resul ting in enhancement ratios 19, 58, and 112 respectively, initially applying 0.10 M atenolol . HCl and (c) increased current density valued 0.1, 0.2, 0 .3, and 0.4 mA/cm(2) obtaining enhancement ratios 6, 18, 36, and 58 respect ively, initially applying 0.10 M atenolol . HCl. Microscopy of hematoxyilin -eosin stained sections of porcine buccal mucosae conducting 8-h passive pe rmeation showed minute morphological alterations whereas 8-h iontophoretic treatment showed disordering of the outer epithelial cell layers, alteratio ns being more pronounced in mucosae from reference chambers than donor cham bers. The results demonstrated the feasibility of the iontophoretic approac h to enhance and control the rate of buccal drug delivery, hence the useful ness of the new permeation cell. (C) 2001 Elsevier Science B.V. All rights reserved.