Equivalence Study of Immediate Release Tablets of Beta Blocker Drug

Abstract

Objective: The therapeutic equivalence of generic brands is a great challenge for manufacturers. This study aimed to evaluate the bioequivalence of four different generic brands of atenolol tablets under biowaiver conditions.
 Methods: Physiochemical properties of the tablet products namely uniformity of weight, hardness, disintegration, and drug content were assessed. The dissolution profiles of atenolol tablets were conducted in pH 1.2, 4.5, 6.8 and 7.6 buffers using USP dissolution apparatus II. Similarity and difference factors were calculated. Finally, four kinetic models have been offered to describe the release characteristics of atenolol under experiment conditions.
 Results: All tablets showed accepted physiochemical characters. Dissolution profiles revealed that G2 showed the highest similarity to innovator (f2 91.86) in pH 7.6. Dissolution kinetics of G2 at the same pH could be best described as Higuchi model of release. 
 Conclusion: The study showed that excipients and manufacturing practices play an important role in marketing biowaiver generic products meet the international regulatory bodies criteria.

Development, Evaluation and in vitro Release Kinetics Study of Immediate Release Tablets of Quercetin Isolated from Bauhinia acuminata Leaves Extract

“…Zero order First order Higuchi Hixon-Crowell Korsmeyer-peppas Comparing the R 2 values of all the formulations First order and Higuchi model showed the better fitting of data. The first order produced greater correlation of all formulations (R 2 =0.987 to 0.998 of) than all other models which indicated that the release of drug from the formulated tablets followed first order release kinetics that is the release is directly proportional to the concentration of the drug (10,11) .…”

“…The data obtained from the in vitro release study were analyzed using linear regression method according to the specified equations of zero order, first order, higuchi model, hixon-crowell model and korsmeyer-peppas model. Different plots were made such as cumulative % drug release vs. time (Zero order kinetic model); log cumulative of % drug remaining vs. time (First order kinetic model); cumulative % drug release vs. square root of time (Higuchi model); cube root of drug % remaining vs. time (Hixson-Crowell cube root law) and log cumulative % drug release vs. log time (Korsmeyer-Peppas model) (10,11) .…”

“…For tablets, if the exponent n = 0.45, then the drug follows Fickian diffusion as its release mechanism and if 0.45< n<0.89, then it follows non-Fickian or anomalous diffusion. An exponent value of 0.89 or more than that indicates Case-II and super Case-II transport mechanisms (10,11,20) .…”

“…In this study the corresponding plot indicated a good linearity in all the formulations (R 2 value 0.931 to 0.949). The release exponent "n" was found to be 0.85 and 0.89 (F3 and F2) which indicated that the drug release mechanism was perhaps controlled by more than one process, diffusion and erosion mechanisms, which is also termed as anomalous diffusion that is coupling of both (10,11,20) .…”