"The Effect of Hydroxyl Containing Tablet Excipients on the Adhesive Duration of Some Mucoadhesive Polymers "

In order to investigate the effect of hydroxyl group containing tablet excipients on the duration of adhesion of mucoadhesive polymers, discs containing Carbopol 934 (C934), polycarbophil (PC), sodium carboxymethyl cellulose, hydroxypropylmethyl cellulose (HPMC), tragacanth (trag.) and sodium alginate (Na alg.), either alone or in the presence of various amounts of excipients were prepared. The duration of adhesion of the prepared discs were determined in pH 7.0 phosphate buffer at 37°C. All the excipients examined reduced the duration of adhesion and the relative durability of the polymer containing discs. HPMC discs despite showing the longest duration of mucoadhesion, suffered the greatest reduction in adhesive properties in the presence of excipients which were examined. Following HPMC, Na alg. and then trag. discs showed the greatest sensitivity to the presence of excipients. The least reduction in the duration of adhesion was observed with PC and C934. Among the excipients tested, spray-dried lactose produced the greatest reduction in the duration of adhesion, followed by polyethylene glycol 6000 and pregelatinized starch. The smallest reduction in the adhesive properties of the test polymers was due to talc powder. Hence, it seems that addition of the tablet excipients adversely reduce the adhesive properties of mucoadhesive dosage forms, which should be carefully considered during their formulation.