title: Development of gastroretentive metronidazole floating raft system for targeting Helicobacter pylori.
abstract: The study demonstrates the feasibility of prolonging gastric residence time and release rate of metronidazole (Mz) by preparing floating raft system (FRS) using ion-sensitive in situ gel forming polymers. FRSs contained 3, 4, 5 and 0.5, 0.75, 1% w/v sodium alginate (Alg) and gellan gum (G), respectively, 0.25% w/v sodium citrate and calcium carbonate (C). Lipids: glyceryl mono stearate (GMS), Precirol(®) and Compritol(®) were incorporated into G-based formulations (G1%C1%). Mz:lipid ratio was 1:1, except for Mz:GMS, ratios of 1:1.5 and 1:2 were also investigated. Buoyancy, gelation capacity and viscosity parameters were evaluated. Drug release and kinetics for selected formulae were examined. The selected lipid containing formula was subjected to an accelerated stability testing. Alg4%C2% FRS exhibited short gelation lag time (3s), long duration (>24h), floating lag time 1m in and duration >24h, and a reliable sustained drug release (MDT 6h). Gellan gum FRSs achieved successful floating gastroretention, but failed to achieve the required gelation capacity. Incorporation of GMS (Mz:GMS 1:1) enhanced the gelation lag time and duration (6s and >24h, respectively), keeping sustained drug release and formulation stability. The improved characteristics of the selected FRS make them excellent candidates for gastric targeting to eradicate Helicobacter pylori.
authors.affiliation: Department of Pharmaceutics, Faculty of Pharmacy and Drug Manufacturing, Pharos University in Alexandria, Egypt.
authors.forename: Nancy Abdel Hamid
authors.initials: NA
authors.lastname: Abou Youssef
authors.affiliation: Department of Pharmaceutical Sciences, Faculty of Pharmacy, Princess Nourah bint Abdulrahman University, Riyadh, Saudi Arabia; Department of Pharmaceutics, Faculty of Pharmacy, Alexandria University, Alexandria, Egypt. Electronic address: abeerkassem2002@gmail.com.
authors.forename: Abeer Ahmed
authors.initials: AA
authors.lastname: Kassem
authors.affiliation: Department of Pharmaceutics, Faculty of Pharmacy and Drug Manufacturing, Pharos University in Alexandria, Egypt.
authors.forename: Magda Abd Elsamea
authors.initials: MA
authors.lastname: El-Massik
authors.affiliation: Department of Pharmaceutics, Faculty of Pharmacy, Alexandria University, Alexandria, Egypt.
authors.forename: Nabila Ahmed
authors.initials: NA
authors.lastname: Boraie
mesh_terms: D000464:Alginates / Q000737:chemistry; D000890:Anti-Infective Agents / Q000737:chemistry*; D004075:Diglycerides / Q000737:chemistry; D016503:Drug Delivery Systems; D065546:Drug Liberation; D005227:Fatty Acids / Q000737:chemistry; D020723:Glucuronic Acid / Q000737:chemistry; D005989:Glycerides / Q000737:chemistry; D016481:Helicobacter Infections; D016480:Helicobacter pylori; D006603:Hexuronic Acids / Q000737:chemistry; D008795:Metronidazole / Q000737:chemistry*; D011135:Polysaccharides, Bacterial / Q000737:chemistry
chemical_list: D000464:Alginates; D000890:Anti-Infective Agents; D004075:Diglycerides; D005227:Fatty Acids; D005989:Glycerides; D006603:Hexuronic Acids; D011135:Polysaccharides, Bacterial; D008795:Metronidazole; C086409:glyceryl behenate; C048159:glyceryl monostearate; C048288:gellan gum; D020723:Glucuronic Acid; C009032:precirol
keywords: Compritol(®); Gelation capacity; Gellan gum; Glyceryl mono stearate; Precirol(®); Sodium alginate