Once Daily Immediate-and Extended-Release Bilayer Tablets of Etoricoxib: A Study on the Release Kinetics

Abstract

Objective: In the present work, the main objective was to develop bilayer extended release matrix tablets of etoricoxib by providing a loading dose followed by maintenance dose that expected to improve the therapeutic efficacy of the medication with less toxic effect.
 Methods: Bilayer tablets of etoricoxib was developed successfully with the meticulous proportion of release controlling Hydroxy propyl methyl cellulose K100 (HPMC K100) and lactose. The tablets were prepared by wet granulation technique. Granules for immediate layer and extended layer for different formulations were prepared separately. The formulations were developed and evaluations were performed to examine the parameters that affect the in vitro performance of the tablets. The drug-excipient compatibility was ensured by Fourier transform infrared spectroscopy (FTIR) study.
 Results: The values of physical parameters of all formulations were found within appreciable limit. Formulation containing HPMC K 100 and lactose in the proportion of 2:1 in the extended release layer was able to release 26.22% of drug in 15 min and shown a steady release of drug for an extended period of 12 h. The dissolution data was put in Korsemeyer–Peppas model in order to find out n value, which describes the drug release mechanism. The n-value of different formulations were found to be variable. The Fourier transform infrared spectroscopy (FTIR) study revealed absence of any other new peaks and also no differences in the positions of the absorption bands in the bilayer tablet F8 that indicate the lack of significant interactions between etoricoxib and other excipients.
 Conclusion: It had been concluded that once daily immediate-and extended release bilayer tablet of etoricoxib can be formulated with profound physical characteristics and dissolution properties. This resulted in reducing the daily dose and thus minimise the cardiovascular toxicity of etoricoxib.

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) .…”