Shoji Ozeki

Mandibular and parotid salivary excretion of procainamide and N-acetylprocainamide after intravenous administration of procainamide to rats

Flow rate, protein level and pH of mandibular and parotid saliva samples in rats were almost stabilized 2h after induction of salivation with pilocarpine (9ṁ0 mg h−1 kg−1). Salivary excretion profiles of procainamide, 50 mg kg−1 i.v., and its metabolite N‐acetylprocainamide (NAPA) were then investigated. Plasma and salivary procainamide levels declined bi‐exponentially with time almost in parallel. Salivary procainamide levels (Y) from both types of gland were correlated with the plasma level (X) over a wide concentration range [Y = 0ṁ108X + 1ṁ96 (r = 0ṁ795) for mandibular and Y = 0ṁ917X (r = 0ṁ974) for parotid glands]. The mean saliva to plasma concentration ratio (S/P ratio) was significantly higher in parotid (0ṁ974 ± 0ṁ243) than in mandibular (0ṁ284 05119) saliva samples. Similar correlations and S/P ratios were observed for NAPA. Procainamide and NAPA mean S/P ratios for saliva from both glands were fairly consistent with the calculated value according to the pH‐partition hypothesis.

Mandibular and parotid salivary levels of indomethacin following intravenous administration to rabbits

Indomethacin was measured in mandibular and parotid saliva, obtained from separate cannulas in the salivary ducts, after bolus intravenous administration (15 mg/kg) to male white rabbits that were stimulated for salivation with pilocarpine given subcutaneously. There was a significant correlation between each salivary drug concentration and plasma drug concentration. Saliva to plasma drug concentration ratio (S/P ratio) and pH were higher in mandibular saliva than in parotid saliva. These gland specific differences were in contrast with the previously reported differences in dogs. Matins equation was found to predict approximately the mean observed S/P ratio of indomethacin for each saliva sample.