<abstract xml:lang="en" xmlns="http://www.w3.org/1999/xhtml">Sustained release (SR) dosage forms enable prolonged and continuous deposition of the drug in the gastrointestinal (GI) tract and improve the bioavailability of medications characterized by a narrow absorption window. In this study, a new strategy is proposed for the development of SR dosage forms for theophylline (TPH). Design of the delivery system was based on a sustained release formulation, with a modified coating technique and swelling features aimed to extend the release time of the drug. Different polymers, such as Carbopol 71G (CP), sodium carboxymethylcellulose (SCMC), ethylcellulose (EC) and their combinations were tried. Prepared matrix tablets were coated with a 5 % (<italic>m/m</italic>) dispersion of Eudragit (EUD) in order to get the desired sustained release profile over a period of 24 h. Various formulations were evaluated for micromeritic properties, drug concentration and <italic>in vitro</italic> drug release. It was found that the <italic>in vitro</italic> drug release rate decreased with increasing the amount of polymer. Coating with EUD resulted in a significant lag phase in the first two hours of dissolution in the acidic pH of simulated gastric fluid (SGF) due to decreased water uptake, and hence decreased driving force for drug release. Release became faster in the alkaline pH of simulated intestinal fluid (SIF) owing to increased solubility of both the coating and matrixing agents. The optimized formulation was subjected to <italic>in vivo</italic> studies in rabbits and the pharmacokinetic parameters of developed formulations were compared with the commercial (Asmanyl®) formulation. Asmanyl® tablets showed faster absorption (<italic>t</italic>max 4.0 h) compared to the TPH formulation showing a <italic>t</italic>max value of 8.0 h. The Cmax and AUC values of TPH formulation were significantly (<italic>p</italic> &lt; 0.05) higher than those for Asmanyl®, revealing relative bioavailability of about 136.93 %. Our study demonstrated the potential usefulness of eudraginated polymers for the oral delivery of the sparingly soluble drug theophylline.</abstract>

Sustained release (SR) dosage forms enable prolonged and continuous deposition of the drug in the gastrointestinal (GI) tract and improve the bioavailability of medications characterized by a narrow absorption window. In this study, a new strategy is proposed for the development of SR dosage forms for theophylline (TPH). Design of the delivery system was based on a sustained release formulation, with a modified coating technique and swelling features aimed to extend the release time of the drug. Different polymers, such as Carbopol 71G (CP), sodium carboxymethylcellulose (SCMC), ethylcellulose (EC) and their combinations were tried. Prepared matrix tablets were coated with a 5 % (m/m) dispersion of Eudragit (EUD) in order to get the desired sustained release profile over a period of 24 h. Various formulations were evaluated for micromeritic properties, drug concentration and in vitro drug release. It was found that the in vitro drug release rate decreased with increasing the amount of polymer. Coating with EUD resulted in a significant lag phase in the first two hours of dissolution in the acidic pH of simulated gastric fluid (SGF) due to decreased water uptake, and hence decreased driving force for drug release. Release became faster in the alkaline pH of simulated intestinal fluid (SIF) owing to increased solubility of both the coating and matrixing agents. The optimized formulation was subjected to in vivo studies in rabbits and the pharmacokinetic parameters of developed formulations were compared with the commercial (Asmanyl®) formulation. Asmanyl® tablets showed faster absorption (tmax 4.0 h) compared to the TPH formulation showing a tmax value of 8.0 h. The Cmax and AUC values of TPH formulation were significantly (p < 0.05) higher than those for Asmanyl®, revealing relative bioavailability of about 136.93 %. Our study demonstrated the potential usefulness of eudraginated polymers for the oral delivery of the sparingly soluble drug theophylline.

Eudraginated polymer blends: A potential oral controlled drug delivery system for theophylline

Department of Pharmaceutical Technology and Raw Materials Development, National Institute for Pharmaceutical Research and Development (NIPRD), Abuja, Nigeria

Department of Pharmacology and Toxicology, National Institute for Pharmaceutical Research and Development (NIPRD), Abuja, Nigeria

Department of Pharmaceutical, Technology and Industrial Pharmacy, University of Nigeria, Nsukka, Enugu state, Nigeria

Acta Pharmaceutica

Sustained release (SR) dosage forms enable prolonged and continuous deposition of the drug in the gastrointestinal (GI) tract and improve the bioavailability...

Eudraginated polymer blends: A potential oral controlled drug delivery system for theophylline

Published Online: Apr 03, 2012

Page range: 71 - 82

DOI: https://doi.org/10.2478/v10007-012-0001-6

Keywords
teofilin, polimerne mješavine, modificirano oslobađanje, oslobađanje, oslobađanje

This content is open access.

Eudraginated polymer blends: A potential oral controlled drug delivery system for theophylline

Published Online: Apr 03, 2012

Page range: 71 - 82

DOI: https://doi.org/10.2478/v10007-012-0001-6

Keywordsteofilin, polimerne mješavine, modificirano oslobađanje, oslobađanje, oslobađanje

This content is open access.

Keywords
teofilin, polimerne mješavine, modificirano oslobađanje, oslobađanje, oslobađanje