Comparative Bioavailability of Four Commercial Quinidine Sulfate Tablets

Bioavailability of Three Commercial Sustained-Release Tablets of Quinidine in Maintenance Therapy

“…This range corresponds closely to the results reported previously (17,18). The mean half-life calculated from the plasma concentration of total quinidine gave nearly the same value (7.46 hr with a standard deviation of 2.36).…”

Biowaiver monographs for immediate release solid oral dosage forms: Quinidine sulfate

“…But drug products which dissolved to more than 85% within 30 min in 0.1 N HCl were found to be bioequivalent 75. A study by Strum et al76, 93 with quinidine, using dissolution in 0.1 N HCl and the basket method at 25 rpm, concluded that values greater than 27 min for 50% release and disintegration times greater than 7 min result in decreased absorption rates, however, do not affect AUC or C max . Hence, rapid dissolution in 0.1 N HCl seems to achieve BE.…”

“…Several in vivo BE studies of quinidine sulfate drug products have been identified,49, 74–76 see Table 4. McGilveray et al75 tested 11 different formulations containing quinidine sulfate, gluconate, or polygalacturonate.…”

“…Strum et al76 tested four different formulation of quinidine sulfate tablets (Quinidine sulfate tablets USP, Eli Lilly & Co., Indianapolis, IN; Quinidine sulfate tablets USP, Phillips Roxane Laboratories, Columbus, OH; Quinidine sulfate tablets USP, Stanlabs, Portland, OR; Quinora tablets, Lakeside Laboratories, Milwaukee, WI) and analyzed AUC, C max , and t max . Significant differences were only found for t max .…”

Mean Time Parameters in Pharmacokinetics

“…At least it is necessary to establish accurately what maximum possible errors can arise from the use of such 'factors'. The application of the recommended dosing interval T = l/ka + l/ke to the determination of the pharmacokinetics of quinidine sulphate tablets with a ka of2.88hi and a ke of0.142hi (treatment A, Strum et al 1977) results in an error of 25%. If the 2 parameters differ by a factor of 2 the error increases to 49%, which is an order of magnitude larger than the error in typical drug concentration data and must therefore be considered unacceptable.…”