Formulation of gastroretentive floating drug delivery system using hydrophilic polymers and its in vitro characterization

Abstract

The aim of the present research is to formulate and evaluate the gastroretentive floating drug delivery system of antihypertensive drug, propranolol HCl. Gastroretentive floating tablets (GRFT) were prepared by using a synthetic hydrophilic polymer polyethylene oxide of different grades such as PEO WSR N-12 K and PEO 18 NF as release retarding polymers and calcium carbonate as gas generating agent. The GRFT were compressed by direct compression strategy and the tablets were evaluated for physicochemical properties, in vitro buoyancy, swelling studies, in vitro dissolution studies and release mechanism studies. From the dissolution and buoyancy studies, F 9 was selected as an optimized formulation. The optimized formulation followed zero order rate kinetics with non-Fickian diffusion mechanism. The optimized formulation was characterised with FTIR studies and observed no interaction between the drug and the polymers.Uniterms: Gastroretentive floating/ drug delivery system. Gastroretentive floating tablets/in vitro dissolution. Hydrophilic polymers/use in drug delivery system. Polyethylene oxide. Propranolol HCl/ delivery system. O objetivo da presente pesquisa é o de formular e avaliar o sistema de liberação de fármaco gastrorretentivo flutuante, contendo o anti-hipertensivo, cloridrato de propranolol. Comprimidos gastrorretentivo flutuantes (GRFT) foram preparados utilizando um polímero hidrofílico sintético, o óxido de polietileno, de diferentes graus, tais como GE WSR N-12 K e GE 18 NF, como polímeros de retardamento de liberação, e carbonato de cálcio, como agente gerador de gases. Os GRFT foram comprimidos por compressão direta e avaliados para determinação das propriedades físico-químicas, flutuabilidade in vitro, estudos de inchamento, de dissolução in vitro e de mecanismo de liberação. Dos testes de dissolução e de flutuabilidade, selecionou-se F 9 como formulação otimizada. A formulação otimizada seguiu cinética de ordem zero, com mecanismo de difusão não-Fickiano. Essa formulação foi caracterizada por estudos de FTIR, não se observando interação entre o fármaco e os polímeros.Unitermos: Retenção gástrica flutuante/sistema de liberação de fármaco. Comprimidos gastrorretentivo flutuante/dissolução in vitro. Polímeros hidrofílicos/uso em sistema de liberação de fármaco. Óxido de polietileno. Cloridrato de propranolol/ sistema de liberação.

Design and statistical optimization of an effervescent floating drug delivery system of theophylline using response surface methodology

“…Drug retarding ability is aff ected by the molecular weight of the polymer (18). Higher molecular weight polymers retarded the drug more effi ciently than polymers with lower molecular weight (12). Based on the present results, PEO N12K appeared to be the best polymer for formulating theophylline eff ervescent fl oating tablets.…”

“…Formulations based on PEO N12K were shown to be readily swellable in the gastric fl uid, thus the tablets were buoyant in less than 1 minute (12). However, formulations containing less than 50 mg xanthan gum disintegrated rapidly in the dissolution medium (12).…”

“…The n value is obtained as a slope by plott ing the log percentage drug released against the log time for diff erent batches (12)…”

“…It has a good absorption window in the upper gastrointestinal tract, making it suitable for GRDDS. Eff ervescent fl oating tablets of theophylline have been developed in order to increase drug effi cacy, to minimize fl uctuation of drug plasma concentration and to reduce concentration-dependent adverse eff ects (12,13).…”

“…Sodium bicarbonate was used as a gas generating agent. Ethyl cellulose and PEO N12K are hydrophobic and hydrophilic polymers, respectively (12,13). Eudragit ® is an anionic copolymer, whereas xanthan gum is a complex exopolysaccharide produced by Xanthomonas campestris (14,15).…”