Journal of Pharmaceutical Research and Opinion 3: 6 (2013) 28 - 35. Contents lists available at www.innovativejournal.in JOURNAL OF PHARMACEUTICAL RESEARCH AND OPINION Journal homepage: http://www.innovativejournal.in/index.php/jpro 28 FUROSEMIDE LOADED SUPERPOROUS HYDROGEL COMPOSITE AS A CONTROLLED RELEASE DEVICE: DIFFERENT STRATEGIES FOR DRUG LOADING Latif R.* 1 Abdel Halim S.A 1 Abdel Kader O.M 1 1 Department of Pharmaceutics, Faculty of Pharmacy, Cairo University ARTICLE INFO ABSTRACT Received 18 th June 2013 Accepted 25 th June 2013 Corresponding Author: Latif R Department of Pharmaceutics, Faculty of Pharmacy, Cairo University, Egypt latifranda@yahoo.co.uk Keywords: controlled release formulation, gastroretentive device, super porous hydrogel composite, furosemide. The aim of the present work was to develop controlled release, gastroretentive device using superporous hydrogel composite (SPHC). Furosemide was chosen as good candidate for such system due to its narrow absorption window, low bioavailability and short half-life. Plain hydrogel was evaluated with respect to swelling ratio, apparent density and floating time. Scanning electron micrographs of SPHC showed large interconnected pores and extensive capillary insertion. Prepared Microspheres were tested for drug content, and tablets evaluated with respect to quality control tests. All loaded formulae inside SPHC were tested for drug release profile. Microspheres, tablets and drug solutions were tested for loading inside SPHC. Kinetic treatment of release data revealed that soaked drug solution was unable to control drug release, where it gave a t 1/2 (0.5hrs) very similar to that of the free drug (0.6hrs). Loaded microspheres showed only a slight retardation in release t 1/2 to 1.06 hrs along with a high percent of flush (~30mg %). However, loaded tablet demonstrated a promising sustained effect corresponding to a release t 1/2 = 6hrs and a low percent of initial flush (~1.2mg %). Therefore, the applicability of SPHC as a controlled release device proved to be largely dependent on the type of dosage form included. ©2013, JPRO, All Right Reserved. INTRODUCTION Since drug delivery technology 1 is an equivalent component in drug development, a design of delivery systems that can target a candidate drug to its absorption site is a successful achievement 2-3 . Among the different systems and devices used to control the drug delivery to the GIT, gastroretentive dosage forms have attracted much attention of academic researchers 4 . Those systems are advantageous in case of drugs characterized by a narrow absorption window. They provide a prolonged intimate contact with the absorbing membrane; thereby, increasing efficacy 5 . For a successful development of a gastroretentive system, the selected dosage form must be able to reside for a time necessary to release the entire drug included before the normal physiology of the stomach can clear up the dosage form to the intestine 6 . Many attempts have been made to attain gastroretention through different systems including bioadhesion 7 or mucoadhesion to gastric mucosa 8-10 , high density systems 11 , floating systems 12-15 , and expandable systems 16 . In our study, we focused specifically on superporous hydrogel systems, as the fast swelling 17 highly porous nature 18-20 of these devices made them excellent candidate materials for gastroretentive delivery of many drugs 5 . Owing to their unique properties, when applied as drug carriers, superporous hydrogels swell to a volume much larger than the opening of the pylorus 21 ; thus, remaining in the stomach for the time necessary to release the loaded drug within their matrices before they begin to degrade 22 . The new technology found extensive pharmaceutical application. Dorkoosh etal succeeded to prepare superporous hydrogel polymers loaded with peptide drugs such as buserelin, octreotide and insulin, and proved that these devices were promising systems for peroral peptide drug delivery 23-24 . Later on, Yin etal were able to improve the intestinal absorption of insulin using superporous hydrogel containing interpenetrating polymer network (IPN) 25 . A more recent study achieved by Gümüşderelioğlu etal demonstrated the superiority of superporous polyacrylate/chitosan interpenetrating network hydrogels for protein delivery. Bovine serum albumin was taken as a model protein. Loading was performed by the soaking method before and after IPN formation 26 .The method of soaking superporous hydrogels in drug solutions was also employed in loading rosiglitazone maleate on swelled polymeric matrix 27 . Mahmoud etal incorporated a self-nanoemulsifying drug delivery system into the SPHC matrix 28 . The incorporation of ranitidine hydrochloride and release retardant polymers in SPHC through a central hole was demonstrated by Chavda etal. A piece of SPHC was used to close the hole by the aid of biodegradable glue. The whole system was used to sustain the delivery of the drug over 17 hours 29 . Furosemide, a famous "high ceiling" loop diuretic, suffers from a short half-life (1-2hrs) and short duration of action (~2hrs), besides a narrow absorption window. All these factors together provided a good rationale for its relatively low