Modulating drug release from gastric-floating microcapsules through spray-coating layers

PLoS One. 2014 Dec 3;9(12):e114284. doi: 10.1371/journal.pone.0114284. eCollection 2014.

Abstract

Floating dosage forms with prolonged gastric residence time have garnered much interest in the field of oral delivery. However, studies had shown that slow and incomplete release of hydrophobic drugs during gastric residence period would reduce drug absorption and cause drug wastage. Herein, a spray-coated floating microcapsule system was developed to encapsulate fenofibrate and piroxicam, as model hydrophobic drugs, into the coating layers with the aim of enhancing and tuning drug release rates. Incorporating fenofibrate into rubbery poly(caprolactone) (PCL) coating layer resulted in a complete and sustained release for up to 8 h, with outermost non-drug-holding PCL coating layer serving as a rate-controlling membrane. To realize a multidrug-loaded system, both hydrophilic metformin HCl and hydrophobic fenofibrate were simultaneously incorporated into these spray-coated microcapsules, with metformin HCl and fenofibrate localized within the hollow cavity of the capsule and coating layer, respectively. Both drugs were observed to be completely released from these coated microcapsules in a sustained manner. Through specific tailoring of coating polymers and their configurations, piroxicam loaded in both the outer polyethylene glycol and inner PCL coating layers was released in a double-profile manner (i.e. an immediate burst release as the loading dose, followed by a sustained release as the maintenance dose). The fabricated microcapsules exhibited excellent buoyancy in simulated gastric fluid, and provided controlled and sustained release, thus revealing its potential as a rate-controlled oral drug delivery system.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Capsules / chemistry*
  • Coated Materials, Biocompatible / chemistry
  • Delayed-Action Preparations / chemistry*
  • Fenofibrate / chemistry
  • Half-Life
  • Hydrophobic and Hydrophilic Interactions
  • Hypoglycemic Agents / chemistry
  • Hypolipidemic Agents / chemistry
  • Metformin / chemistry
  • Piroxicam / chemistry

Substances

  • Capsules
  • Coated Materials, Biocompatible
  • Delayed-Action Preparations
  • Hypoglycemic Agents
  • Hypolipidemic Agents
  • Piroxicam
  • Metformin
  • Fenofibrate

Grants and funding

The authors would also like to acknowledge the financial support from the Singapore Centre on Environmental Life Sciences Engineering (SCELSE) (M4330001.C70.703012), the School of Materials Science and Engineering (M020070110), Solar Fuels Laboratory Nanyang Technological University (M060070008), and the NTU-National Healthcare Group (NTU-NHG) grant (ARG/14012). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.