title: The effect of moisture on the heckel and energy analysis of hydroxypropylmethylcellulose 2208 (HPMC K4M).
abstract: The influence of moisture content on the Heckel analysis, energy analysis and strain-rate sensitivity of hydroxyproplymethylcellulose 2208 (HPMC K4M) has been evaluated. An increase in moisture content from 0 to 14.9% w/w decreased the mean yield pressure, probably due to a plasticizing effect of moisture which reduced the resistance of particles to deformation. For each moisture content (0, 2.2, 3.8, 5.9, 9.6 and 14.9% w/w), the initial relative density and the extrapolated density from the linear portion of the Heckel plot, tended to decrease with increasing compression speed. Minor changes were observed in the initial relative density due to changes in the moisture content. The strain-rate sensitivity increased from 21.6 to 50.7% as the moisture content increased from 0 to 14.9% w/w, indicating that the plasticity of HPMC increased with increase in moisture content, whereas increase in moisture content from 0 to 14.9% w/w decreased the plastic energy. Increase in compression force or speed of compaction increased both the plastic and elastic energies. An increase in moisture content from 0 to 5.9% w/w slightly reduced the elastic energy but above 5.9% moisture content the elastic energy was unaffected by the moisture content.
authors.affiliation: Pharmaceutical Technology and Drug Delivery Group, School of Pharmacy and Chemistry, Liverpool John Moores University, UK.
authors.forename: A
authors.initials: A
authors.lastname: Nokhodchi
authors.forename: J L
authors.initials: JL
authors.lastname: Ford
authors.forename: P H
authors.initials: PH
authors.lastname: Rowe
authors.forename: M H
authors.initials: MH
authors.lastname: Rubinstein
mesh_terms: D000704:Analysis of Variance; D002626:Chemistry, Pharmaceutical / Q000379:methods; D004548:Elasticity; D005079:Excipients; D006244:Hardness; D065347:Hypromellose Derivatives; D008747:Methylcellulose / Q000031:analogs & derivatives* / Q000737:chemistry; D008954:Models, Biological; D010316:Particle Size; D011480:Protease Inhibitors / Q000737:chemistry*; D012995:Solubility; D013607:Tablets; D013678:Technology, Pharmaceutical; D013718:Tensile Strength
chemical_list: D005079:Excipients; D011480:Protease Inhibitors; D013607:Tablets; D065347:Hypromellose Derivatives; D008747:Methylcellulose