Abstract
The physicochemical properties of free films made from different mixtures of sustained release polymers were investigated, and an optimum formulation coating on drug containing pellets, based on the study of free film was evaluated. In order to determine the effect of different variables on the permeability and swelling of films and procedure optimization, the experimental design was fulfilled based on the statistical method of a 3(3) full factorial design, and according to this method 27 formulations were prepared. The films were prepared using casting-solvent evaporation method. Water vapor permeability, the swelling and permeability of free films in both acidic and buffer media, were carried out. Then, the pellets containing theophylline were coated with the optimum formulation. The results of this study demonstrated that an increase in the free film thickness and Eurdragit RS ratio in films lowered the water vapor transmission (WVT), the swelling and the permeability of all formulations, while an increase in the quantity of ethylcellulose, up to a specific ratio (approximately 40%), decreased the permeability and swelling. The most optimum free film formulation was made up of 60% Eudragit RS and 40% ethylcellulose. Pellets coated with a 10% coating level of ethylcellulose and Eudragit RS (4:6) showed suitable release properties and could serve as a favorable sustained release system for theophylline.
Highlights
Controlled release technology, which is used in the formulation of pharmaceutical product, has become increasingly important due to its significant role in recent pharmaceutical technology
The results of this study demonstrated that an increase in the free film thickness and Eurdragit RS ratio in films lowered the water vapor transmission (WVT), the swelling and the permeability of all formulations, while an increase in the quantity of ethylcellulose, up to a specific ratio, decreased the permeability and swelling
From the results there was a decrease in WVT with increasing film thickness, and this could have resulted from the prolonged pathway of water vapor molecules through the films
Summary
Controlled release technology, which is used in the formulation of pharmaceutical product, has become increasingly important due to its significant role in recent pharmaceutical technology. Eudragit RL (ERL) and Eudragit RS (ERS) are acrylic and methacrylic acid esters, respectively, having some hydrophilic properties due to the presence of quaternary ammonium groups; where ERL possesses higher amount (50 mEq/100 g polymer) of such groups than ERS (25 mEq/100 g polymer).[10] They are mainly used as film coatings in tablets, granules and other small particles, The release characteristics of film coated controlled release formulations are strongly dependent on the swelling ability and permeability of the film From another point of view, the study on drug permeation through free films of polymeric materials could be useful in understanding and predicting the properties of coatings on the surface of a dosage form. The authors included that the diffusion of drug through isolated plasticized
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
