Relevancy of Nizatidine’s Release from Floating Tablets with Viscosity of Various Cellulose Ethers
Department of Pharmacy, COMSATS University Islamabad, Lahore 54000, Pakistan
Faculty of Pharmacy, University of Central Punjab, Lahore 54000, Pakistan
Department of Pharmaceutics, Faculty of Pharmaceutical Sciences, Government College University, Faisalabad 38000, Pakistan
Department of Pharmaceutical Sciences, Hampton University School of Pharmacy, Hampton, VA 23668, USA
Authors to whom correspondence should be addressed.
Academic Editor: Fawaz Aldabbagh
Sci 2021, 3(2), 22; https://doi.org/10.3390/sci3020022
Received: 8 April 2019 / Revised: 1 April 2021 / Accepted: 7 April 2021 / Published: 8 April 2021
Nizatidine is a gastroprotective drug with a short biological half-life and narrow absorption window. This study aimed at developing floating tablets of nizatidine using various HPMC viscosity grades, namely K4M, E4M, K15 and K200M. Directly compressed tablets revealed an excellent uniformity in hardness, thickness and weight and nizatidine was evenly distributed within the matrix floating tablets. Buoyancy study revealed floating lag time as low as 18–38 s, and tablets remain buoyant for upto 24 h. However, the later depended upon viscosity grade of HPMC and that the higher the viscosity, the less was the total floating time. In vitro dissolution indicated viscosity dependent nizatidine release from the floating tablets. HPMC K4M and E4M based floating tablets released almost 100% drug in 12 h, whilst higher viscosity polymers such as K15 and K200M only released 81.88% and 75.81% drug, respectively. The drug release followed non-Fickian diffusion from tablets formulated with K4M, K15 and K200M, whilst super case II transport was observed with E4M based tablets. More interestingly, K4M and E4M polymers have similar viscosity yet exhibited different drug release mechanism. This was attributed to the difference in degree of substitution of methoxyl- and hydroxypropoxyl- groups on polymer backbone.