Design and Characterization of Bilayered Floating Tablets of Clopidogrel Bisulfate and Aspirin using Natural Gums

Abstract

Objectives: In present investigation, an attempt was made to develop bilayered floating tablets of clopidogrel bisulfate and aspirin using natural gums as release retarded material. Clopidogrel bisulfate and aspirin are anti-platelet agents. Methodology: Clopidogrel bisulfate is a suitable candidate for formulating as gastro retentive dosage form as it has absorption window in stomach and solubility in the acidic pH. Sodium bicarbonate and citric acid were used to get desired floating properties. The effect of formulation variables on floating properties and drug release were investigated. Results: The tablets so designed were evaluated and found to have acceptable physicochemical properties, floating lag time, floating time and drug release. Among all the bilayered formulations, CBXA with susutained.release layer containing xanthan gum (2 ratio with drug), sodium bicarbonate (15% w/w) and citric acid (1.2% w/w) and immediate release layer containing sodium bicarbonate (10% w/w) and guar gum (4% w/w) has shown optimum results. Sustained release layer has shown dissolution of 99.03±0.42 % in 12 hrs whereas immediate release layer has shown 99.4±0.44 % in 30mins.CBXA has shown optimum floating properties with in vitro floating lag time of 4 min and floating time of >12 hr. In vivo buoyancy study revealed that the floating time of CBXA was greater than 6 hr. The in vitro release data of optimized formulation was treated with mathematical equations and was evident that drug release followed zero order kinetics with case II transport mechanism. Conclusion: Based on the results it can be found that bilayered floating tablets of clopidogrel bisulfate and aspirin containing xanthan gum provides a better approach for sustained release and improved bioavailability.

Development and assessment of immediate-release tablets containing clopidogrel bisulphate & aspirin—strategy for optimizing the combination formulation

“…In clopidogrel bisulphate (pure), a strong absorbance band was found at 1750.732 cm –1 due to C = O stretching vibrations, at 1171.732 due to C-O stretching and at 2986–2830 cm –1 due to O–H stretching of the hydrogen sulfate moiety. This study aligns well with the values published in the literature [ 37 , 38 , 42 ]. In case of aspirin, carboxylic acid is the principal functional group.…”

“…The IR spectra suggested that there were no significant changes in the peaks, thus, it is concluded that the excipients used in the formulations are very much compatible with both the drugs. This study provides a good understanding of the existing literature [ 40 , 42 , 43 ].…”

“…The IR spectra of aspirin demonstrated the stretching vibration of C = O bonds between the 1679.306–1749.064 cm -1 and a band at 1603.12 cm -1 is accredited with the vibration of the benzene ring whereas multiple bands are in the range of 1600–1000 cm -1 [ 43 ]. In the physical mixture of aspirin and clopidogrel ( Fig 8 ) there are no major transformations in the prominent peaks of both the drugs i.e clopidogrel and aspirin [ 42 ].…”