title: Development of self-microemulsifying bilayer tablets for pH-independent fast release of candesartan cilexetil.
abstract: The aim of this study was to design self-microemulsifying tablets for pH-independent fast release of poorly soluble candesartan cilexetil (CDC). To improve the solubility of CDC, a self-microemulsifying drug delivery system (SMEDDS) was prepared composed of Capryol 90, Tween 80 and tetraglycol at a ratio of 5:35:60. Drug containing SMEDDS was adsorbed onto Fujicalin and Neusilin UFL2, respectively, used as solidification carriers and subsequently compressed into tablets (self-microemulsifying tablet, SMET). SMET using Fujicalin exhibited immediate CDC release in pH 1.2 medium while Neusilin UFL2-based SMET showed fast release, especially at pH 6.5. Thus, optimized SMET could be produced with one layer of Fujicalin and the other layer with Neusilin UFL2, demonstrating CDC release of 75% of the initial dose within 15 min in all pH conditions (1.2, 4.5, and 6.5). The average diameter of emulsion droplets formed from SMET was less than 200 nm. It was thus expected that Fujicalin and Neusilin UFL2-based bi-layer SMET would overcome low oral bioavailability of CDC due to its limited solubility at physiological pH conditions in the gastrointestinal tract.
authors.affiliation: Pharmaceutical Formulation Design Laboratory, College of Pharmacy, Chung-Ang University, Seoul, Korea.
authors.forename: Yesung
authors.initials: Y
authors.lastname: Sohn
authors.forename: Su Yeon
authors.initials: SY
authors.lastname: Lee
authors.forename: Ga Hyeon
authors.initials: GH
authors.lastname: Lee
authors.forename: Yeon-Joo
authors.initials: YJ
authors.lastname: Na
authors.forename: Seong Yeon
authors.initials: SY
authors.lastname: Kim
authors.forename: Ilkyeong
authors.initials: I
authors.lastname: Seong
authors.forename: Beom-Jin
authors.initials: BJ
authors.lastname: Lee
authors.forename: Hyo-Jeong
authors.initials: HJ
authors.lastname: Kuh
authors.forename: Jaehwi
authors.initials: J
authors.lastname: Lee
mesh_terms: D047228:Angiotensin II Type 1 Receptor Blockers / Q000008:administration & dosage* / Q000032:analysis; D001562:Benzimidazoles / Q000008:administration & dosage* / Q000032:analysis; D001713:Biphenyl Compounds / Q000008:administration & dosage* / Q000032:analysis; D002626:Chemistry, Pharmaceutical; D004339:Drug Compounding; D016503:Drug Delivery Systems; D004563:Electrochemistry; D004655:Emulsions; D006863:Hydrogen-Ion Concentration; D008855:Microscopy, Electron, Scanning; D010316:Particle Size; D012995:Solubility; D013607:Tablets; D013777:Tetrazoles / Q000008:administration & dosage* / Q000032:analysis
chemical_list: D047228:Angiotensin II Type 1 Receptor Blockers; D001562:Benzimidazoles; D001713:Biphenyl Compounds; D004655:Emulsions; D013607:Tablets; D013777:Tetrazoles; C077793:candesartan cilexetil