Original Article EFFECT OF VARIOUS SUSTAINED RELEASE POLYMERS ON FLOATING TABLETS OF CARVEDILOL PHOSPHATE-A COMPARATIVE STUDY K. RAVI SHANKAR 1 , SHAIK AMINABEE 2* , KNV CHENCHU LAKSHMI 1 , G. RAMANA REDDY 1 , REEHANA SHAIK 1 , VINEETHA TIYAGURA 1 , SHAIK ALMAAS SULTANA 1 , SHAIK BASHA 1 , KANDEPU MOKESH SAI 1 , JALADI BHAGAVAN 1 , CHELLI DINESH KUMAR 1 1 KVSR Siddhartha College of Pharmaceutical Sciences, Vijayawada, Krishna, Andhra Pradesh, India. 2* V. V. Institute of Pharmaceutical Sciences, Gudlavalleru-521356, Krishna, Andhra Pradesh, India * Corresponding author: Shaik Aminabee; * Email: aminaammi786@gmail.com Received: 19 Aug 2023, Revised and Accepted: 04 Oct 2023 ABSTRACT Objective: This study aimed to develop floating tablets of Carvedilol phosphate containing various excipients such as HPMC K100M, Carbopol, Polyox WSR, HPMC K4M, and sodium bicarbonate to generate gas. Additionally, the impact of DCP, spray dried lactose, and HPβCD on drug release was investigated. Methods: A total of eighteen formulations were prepared using the direct compression method and evaluated for hardness, drug content, friability, floating lag time, floatation time and drug release properties. Results: FTIR analysis confirmed that there were no chemical interactions between Carvedilol phosphate and the excipients used in the formulation of the floating tablets. Most of the Carvedilol phosphate floating tablets, except for F9 and F10, did not disintegrate in water, alkaline fluids (pH 7.4), or acidic aqueous solutions (pH 1.2). These tablets exhibited satisfactory quality attributes in terms of hardness, drug content, and friability, making them suitable for sustained release. The floating lag time of the tablets ranged from 25 seconds to 34 min, while the floating duration varied from 2 to 24 h. The drug release from the tablets was gradual and sustained over 12 h, depending on the composition of the tablets. Polyox WSR (F9 and F10) resulted in a rapid drug release, whereas an increase in the polymer concentration led to a decrease in the rate of drug release across all formulations. Conclusion: The study reveals that the use of hydrophilic polymers enhanced the drug release, whereas hydrophobic polymers decreased the drug release. As such, formulations, F11, F15, and F16, which gave 100% drug release within 12 h are finalized as the optimized formulations of Carvedilol phosphate floating tablet. Keywords: Carvedilol phosphate, Floating, Polymers, Sustained release © 2023 The Authors. Published by Innovare Academic Sciences Pvt Ltd. This is an open access article under the CC BY license (https://creativecommons.org/licenses/by/4.0/) DOI: https://dx.doi.org/10.22159/ijap.2023v15i6.49170. Journal homepage: https://innovareacademics.in/journals/index.php/ijap INTRODUCTION The drug administration through oral route is the most reliable drug delivery system because of its comfort and easy way of consumption. A solid drug dosage is more robust stable and also exhibits additional advantages such as easy to handle and popular way of medicine consumption. Hence, better subject compliance and drug treatment can be observed with oral route of medications than with any other administration routes of dosage forms. Carvedilol is chemically named as “(±)-1-(Carbazol-4-yloxy)-3-[[2-(o-methoxyphenoxy)ethyl]amino]-2- propanol”. Carvedilol is preferred in the management of hypertension, decreases rate of heart myocardial contractility rate and also reduces systolic pressure when diastolic pause increases. It is a third-generation lipophilic molecule, which is highly nonselective β1 adrenergic receptor blocking agent selectively blocks the β1adrenoceptor with α1-blocking activity coordinated vascular dilatory action and significant action on the function of vascular endothelial cells [1, 2]. Blocking receptors have effects like decreases in stroke and cardiac output capacity, heart muscle oxygen consumption, plasma renin activity, and inhibition of norepinephrine release [3]. Carvedilolcomes under Class II of BCS Classification which distinguish by low dissolution rate (due to its less aqueous solubility) and has a less plasma half-life of about 6 h with an elimination half-life of 2 h. Due to its poor solubility in alkaline pH environments, the bioavailability of Carvedilol Phosphate is negatively affected, limiting its absorption at the intended site [4]. Therefore, Carvedilol Phosphate is a suitable candidate for the formulation of gastroretentive floating tablets, as it can enhance its bioavailability by prolonging gastric residence time and achieving sustained release for twice-daily administration over 12 h [3]. This study aims to develop and assess floating tablets of Carvedilol Phosphate using various matrix-forming polymers such as HPMC K100 M, Carbopol, Polyox WSR, and HPMC K4M. The tablets will be evaluated for hardness, drug content, friability, disintegration time, floating time, floating lag time, as well as drug release kinetics and mechanisms. MATERIALS AND METHODS Chemical/reagents Carvedilol phosphate and was a gift sample from M/s Aizant Drug Research Solutions Pvt. Ltd., Hyderabad. HPMC K100 and K4M, Carbopol, Polyox WSR, sodium bicarbonate, dicalcium phosphate (DCP), lactose were procured from commercial sources. All other materials used were of Pharmacopoeial grade. Formulation of carvedilol phosphate floating tablets The preparation of Carvedilol phosphate tablets involved utilizing HPMC K100M, Carbopol, Polyox WSR, and HPMC K4M as matrix- forming polymers, while sodium bicarbonate was employed as a gas- generating agent. Lactose and dicalcium phosphate were used as fillers. A total of twenty different formulations of Carvedilol phosphate floating tablets were developed using various combinations of matrix-forming agents and fillers through the direct compression method [5]. Methods of preparation of floating tablets of carvedilol phosphate To prepare the Carvedilol phosphate floating tablets, the predetermined quantities of Carvedilol phosphate, matrix-forming polymer, sodium bicarbonate, fillers, talc, and magnesium stearate were thoroughly mixed inside a closed polyethylene bag. The mixing process ensured the homogeneity of the powder blend. Subsequently, a multi-station tablet compression machine was International Journal of Applied Pharmaceutics ISSN- 0975-7058 Vol 15, Issue 6, 2023