title: The development of sustained release drug delivery platforms using melt-extruded cellulose-based polymer blends.
abstract: OBJECTIVE
  This research examined the application of hot melt extrusion (HME) in the preparation of matrix formulations containing hydroxypropyl cellulose (HPC) as a base polymer in combination with methyl cellulose (MC) and hydroxypropyl methylcellulose (HPMC).
  
  
  METHODS
  The limit to which formulations could control drug release under varying paddle speeds, high alcohol environments and high and low drug loads was investigated on a Caleva 10 ST dissolution tester. Rheological studies and hot plate imaging highlighted the impact of thermoresponsive polymers on drug release. The rate and percentage release of drug were analysed using a one-way ANOVA and Tukey's HSD test.
  
  
  RESULTS
  No significant differences in the amount of drug released were calculated as a result of paddle speed variation or in the presence of 40% v/v ETOH. The phase separation effects of temperature-sensitive polymers HPC and MC and the characteristic gel shrinkage and fluid expulsion were shown to be contributing factors. The use of the partition activity, α, identified the extent to which formulations were affected by phase separation.
  
  
  CONCLUSIONS
  Hot melt extrusion was successfully used to manufacture cellulose-based formulations. Thermoresponsive polymers HPC and MC significantly impacted drug release properties.
authors.affiliation: School of Pharmacy, Queen's University Belfast, Belfast, UK.
authors.forename: Matthew R
authors.initials: MR
authors.lastname: Wilson
authors.affiliation: School of Pharmacy, Queen's University Belfast, Belfast, UK.
authors.forename: David S
authors.initials: DS
authors.lastname: Jones
authors.affiliation: School of Pharmacy, Queen's University Belfast, Belfast, UK.
authors.forename: Gavin P
authors.initials: GP
authors.lastname: Andrews
mesh_terms: D002482:Cellulose / Q000031:analogs & derivatives / Q000737:chemistry; D002626:Chemistry, Pharmaceutical; D003692:Delayed-Action Preparations; D004339:Drug Compounding / Q000379:methods*; D065546:Drug Liberation; D004355:Drug Stability; D000431:Ethanol / Q000494:pharmacology; D006358:Hot Temperature; D006801:Humans; D065347:Hypromellose Derivatives / Q000737:chemistry*; D008747:Methylcellulose / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*; D012995:Solubility
chemical_list: D003692:Delayed-Action Preparations; D011108:Polymers; D000431:Ethanol; D065347:Hypromellose Derivatives; D002482:Cellulose; D008747:Methylcellulose; C008079:hydroxypropylcellulose
keywords: controlled release; hot melt extrusion; hydroxypropyl cellulose; low critical solution temperature; phase separation