Development of Mixed Matrix Membranes for Controlled Release of Ibuprofen C. Algieri, 1 E. Drioli, 1,2 L. Donato 1 1 National Research Council, Institute on Membrane Technology (ITM–CNR), The University of Calabria, 87036 Rende CS, Italy 2 Department of Chemical Engineering and Materials, University of Calabria, 87036 Rende CS, Italy Correspondence to: L. Donato (E-mail: l.donato@itm.cnr.it) ABSTRACT: In this work was studied the effect of different zeolite topologies on the release of ibuprofen from mixed matrix mem- branes (MMMs). The main parameters investigated were: zeolite concentration, its hydrophilic/hydrophobic character, and drug load- ing. About the different investigated systems, the PDMS NaX (I) membrane seems to be the most promising for its application as transdermal device. The release data were fitted with different mathematical models (zero order, first order, Higuchi, Bhaskar, and Korsemeyer-Peppas) to give a possible explanation of the release mechanism of the drug from MMMs. The release data of the drug from pure PDMS membranes (PDMS IBU) were fitted by the Higuchi model (R 2 pari a 0.97). In the case of MMMs, the correlation coefficients are very far from the unit value except for the PDMS NaX (I) system that obeys to the Korsmeyer–Peppas (0.98) and Bashkar (0.99) models. V C 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 000: 000–000, 2012 KEYWORDS: controlled release; mixed matrix membranes; FAU zeolite; LTA zeolite; Ibuprofen; transdermal patches Received 4 April 2012; accepted 20 May 2012; published online DOI: 10.1002/app.38102 INTRODUCTION Ibuprofen (2-(4-isobutylphenyl) propionic acid) is a nonsteroi- dal anti-inflammatory drug used widely in rheumatoid arthritis, osteoarthritis, and in other painful conditions. Using conven- tional formulations, ibuprofen is rapidly absorbed, and the peak serum concentrations occur within 1–2 h. 1,2 Its short biological half life (2 h) requires multiple daily dosing. To reduce the frequency of administration and to improve the patient compli- ance, a controlled release is necessary. Today, many polymers such as polyurethanes, polyanhydrides, and siloxanes are used for the development of controlled drug delivery devices. 3–5 In this context, different papers present in the open literature are focused on the oral sustained release of ibuprofen. 6–9 Transder- mal patches are innovative drug delivery systems that give the possibility to by-pass the gastrointestinal tract avoiding both its irritation that normally occurs and partial first-pass inactivation by the liver. 10–13 Up to date, mixed matrix membranes (MMMs) were studied for gas and liquid mixture separa- tions, 14–16 but the possibility to use them for a sustained drug release was not yet explored. In this work, MMMs loaded with different zeolite topologies [Faujasite (FAU) and Linde Type A (LTA)] were studied as a novel transdermal devices for the con- trolled release of ibuprofen. Zeolites are alumino-silicate materi- als having crystalline structure with micropore aperture size in the range of molecular dimensions (3–10 A ˚ ). It is possible to change their adsorption properties varying the Si/Al ratio dur- ing the synthesis. 17 These materials are used in different fields: industrial, agricultural, and pharmacological. 18 Several toxico- logical studies showed that the natural zeolite clinoptiolite is a nontoxic and safe material used in human and veterinary medi- cine. 19 It is ascertained as dermal uptake of the zeolite is negli- gible for long time on the undamaged skin. 20,21 For example, pharmaceutical zeolite-based compositions containing zinc and erythromycin have been used in the treatment of acne. 22 Besides, FAU zeolite acts as a slow release agent for different anthelmintic drugs. 23 In this study, the release of ibuprofen from the MMMs was investigated with the aim to evaluate the effect of zeolite adsorption properties on the release kinetics. Besides, different mathematical models were used to determine the kinetics of drug release from drug delivery systems. EXPERIMENTAL Materials Ibuprofen ((RS)-2-(4-(2-methylpropyl)phenyl) propanoic acid, C 13 H 18 O 2 ) was kindly supplied by Centro Ricerche per le Ener- gie Non Convenzionali–Istituto Eni Donegani di Novara (Italy). Polydimethylsiloxane (PDMS, Sylgard (R) 184 silicone elasto- mer) polymer, used to prepare the membranes, was supplied by Dow Corning Co. NaX (Faujasite) and NaA (Linde type A) V C 2012 Wiley Periodicals, Inc. WWW.MATERIALSVIEWS.COM WILEYONLINELIBRARY.COM/APP J. APPL. POLYM. SCI. 2012, DOI: 10.1002/APP.38102 1