title: pH-enzyme di-dependent chronotherapeutic drug delivery system of theophylline for nocturnal asthma.
abstract: The purpose of this research work was to develop and evaluate a chronotherapeutic based colon-targeted drug delivery system of theophylline (THEO) exploiting pH-enzyme sensitive property for the prevention of episodic attack of asthma in early morning. Guar gum microspheres of theophylline were prepared by emulsification technique. Coating of microspheres was performed using solvent evaporation method with pH sensitive Eudragit(®) polymers. The particle size and surface morphology, entrapment efficiency and degree of swelling of microspheres were examined. The in vitro drug release studies were performed in pH progression medium and also in the presence of 2% rat caecal content. Theophylline was efficiently microencapsulated in guar gum microspheres at different polymer concentrations (1-4%). Fourier transform infrared (FT-IR)-spectroscopy confirmed the intermolecular interactions between guar gum and glutaraldehyde. Coating of guar gum microspheres by Eudragit led to decelerate the in vitro drug release of THEO. Moreover in vitro drug release studies also performed with 2% rat caecal content showed marked increment in drug release. The controlled release of THEO after a lag time was achieved with developed formulation for chronotherapeutic delivery. The pH dependent solubility behavior of Eudragit and gelling properties of guar gum are found to be responsible for delaying the release.
authors.affiliation: SLT Institute of Pharmaceutical Sciences, Guru Ghasidas Vishwavidyalaya, Bilaspur, India.
authors.forename: Murari Lal
authors.initials: ML
authors.lastname: Soni
authors.forename: Kamta Prasad
authors.initials: KP
authors.lastname: Namdeo
authors.forename: Sunil Kumar
authors.initials: SK
authors.lastname: Jain
authors.forename: Manish
authors.initials: M
authors.lastname: Gupta
authors.forename: Jawahar Singh
authors.initials: JS
authors.lastname: Dangi
authors.forename: Manoj
authors.initials: M
authors.lastname: Kumar
authors.forename: Yuvraj Singh
authors.initials: YS
authors.lastname: Dangi
mesh_terms: D000818:Animals; D001249:Asthma / Q000188:drug therapy* / Q000378:metabolism; D055870:Drug Chronotherapy; D016503:Drug Delivery Systems / Q000379:methods*; D005685:Galactans / Q000008:administration & dosage / Q000737:chemistry / Q000493:pharmacokinetics; D006863:Hydrogen-Ion Concentration; D008351:Mannans / Q000008:administration & dosage / Q000737:chemistry / Q000493:pharmacokinetics; D008863:Microspheres; D053149:Plant Gums / Q000008:administration & dosage / Q000737:chemistry / Q000493:pharmacokinetics; D011109:Polymethacrylic Acids / Q000008:administration & dosage / Q000737:chemistry / Q000493:pharmacokinetics; D051381:Rats; D017207:Rats, Sprague-Dawley; D013806:Theophylline / Q000008:administration & dosage* / Q000737:chemistry / Q000493:pharmacokinetics
chemical_list: D005685:Galactans; D008351:Mannans; D053149:Plant Gums; D011109:Polymethacrylic Acids; C038300:methylmethacrylate-methacrylic acid copolymer; D013806:Theophylline; C007894:guar gum