title: Development of a gastroretentive pulsatile drug delivery platform.
abstract: OBJECTIVE
  To develop a novel gastroretentive pulsatile drug delivery platform by combining the advantages of floating dosage forms for the stomach and pulsatile drug delivery systems.
  
  
  METHODS
  A gastric fluid impermeable capsule body was used as a vessel to contain one or more drug layer(s) as well as one or more lag-time controlling layer(s). A controlled amount of air was sealed in the innermost portion of the capsule body to reduce the overall density of the drug delivery platform, enabling gastric floatation. An optimal mass fill inside the gastric fluid impermeable capsule body enabled buoyancy in a vertical orientation to provide a constant surface area for controlled erosion of the lag-time controlling layer. The lag-time controlling layer consisted of a swellable polymer, which rapidly formed a gel to seal the mouth of capsule body and act as a barrier to gastric fluid ingress.
  
  
  RESULTS
  By varying the composition of the lag-time controlling layer, it was possible to selectively program the onset of the pulsatile delivery of a drug.
  
  
  CONCLUSIONS
  This new delivery platform offers a new method of delivery for a variety of suitable drugs targeted in chronopharmaceutical therapy. This strategy could ultimately improve drug efficacy and patient compliance, and reduce harmful side effects by scaling back doses of drug administered.
authors.affiliation: College of Pharmacy, The University of Texas at Austin, Austin, TX 78712, USA.
authors.forename: Sumalee
authors.initials: S
authors.lastname: Thitinan
authors.forename: Jason T
authors.initials: JT
authors.lastname: McConville
mesh_terms: D003692:Delayed-Action Preparations; D055870:Drug Chronotherapy; D016503:Drug Delivery Systems; D064420:Drug-Related Side Effects and Adverse Reactions; D005753:Gastric Mucosa / Q000378:metabolism; D006801:Humans; D055118:Medication Adherence; D004364:Pharmaceutical Preparations / Q000008:administration & dosage* / Q000378:metabolism; D011108:Polymers / Q000737:chemistry*; D013997:Time Factors
chemical_list: D003692:Delayed-Action Preparations; D004364:Pharmaceutical Preparations; D011108:Polymers