Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1-2
pubmed:dateCreated
2007-7-30
pubmed:abstractText
The purpose of the study was to investigate the physical state of hot-melt extruded guaifenesin tablets containing either Acryl-EZE or Eudragit L100-55 and to study the physicochemical factors influencing crystal growth of guaifenesin on the surface of the extrudates. The powder mixtures containing Acryl-EZE were extruded on a single-screw Randcastle Microtruder at 20rpm and at temperatures of 90, 95, 110 degrees C (zones 1, 2, 3, respectively) and 115 degrees C (die), before being manually cut into tablets (250+/-5mg). Extrudates containing Eudragit L100-55, TEC and guaifenesin were extruded at temperatures ranging from 60 to 115 degrees C. Modulated differential calorimetry (DSC) was used to demonstrate the plasticizing effect of guaifenesin on Eudragit L100-55. Powder X-ray diffraction (PXRD) showed that while the drug powder is crystalline, extrudates containing up to 25% drug exhibited an amorphous diffraction profile. Extrudates containing higher drug concentrations showed an amorphous profile with some crystalline peaks corresponding to guaifenesin, indicating that the limit of solubility of drug in the matrix had been exceeded. Scanning electron microscopy was used to demonstrate that drug crystallization was a surface phenomenon and dependent on the drug concentration. In vitro dissolution testing showed no effect of surface crystallization of guaifenesin on drug release rates of extruded matrix tablets. The influence of hydrophilic polymeric additives including PVP K25, polycarbophil, PEG 3,350, poloxamer 188 or poly(ethylene oxide) as crystal growth inhibitors was investigated at a level of 10% based on the drug content. The extent of crystal growth was reduced for all additives. Complete drug release in pH 6.8 phosphate buffer was prolonged from 4h in extrudates containing Acryl-EZE and guaifenesin to 8h in extrudates containing Eudragit L100-55, TEC and guaifenesin. Drug release in extrudates containing Eudragit L100-55 and guaifenesin was not affected by the presence of hydrophilic additives present at 10% based on the drug content. In vitro drug release studies showed no significant change during storage for up to 6 months at 25 degrees C/60% relative humidity and 40 degrees C/75% relative humidity.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0378-5173
pubmed:author
pubmed:issnType
Print
pubmed:day
16
pubmed:volume
341
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
162-72
pubmed:meshHeading
pubmed-meshheading:17524578-Acrylic Resins, pubmed-meshheading:17524578-Calorimetry, Differential Scanning, pubmed-meshheading:17524578-Chemistry, Pharmaceutical, pubmed-meshheading:17524578-Citrates, pubmed-meshheading:17524578-Crystallization, pubmed-meshheading:17524578-Crystallography, X-Ray, pubmed-meshheading:17524578-Drug Carriers, pubmed-meshheading:17524578-Drug Compounding, pubmed-meshheading:17524578-Drug Stability, pubmed-meshheading:17524578-Drug Storage, pubmed-meshheading:17524578-Excipients, pubmed-meshheading:17524578-Guaifenesin, pubmed-meshheading:17524578-Humidity, pubmed-meshheading:17524578-Hydrogen-Ion Concentration, pubmed-meshheading:17524578-Kinetics, pubmed-meshheading:17524578-Microscopy, Electron, Scanning, pubmed-meshheading:17524578-Plasticizers, pubmed-meshheading:17524578-Polymers, pubmed-meshheading:17524578-Powder Diffraction, pubmed-meshheading:17524578-Solubility, pubmed-meshheading:17524578-Surface Properties, pubmed-meshheading:17524578-Tablets, Enteric-Coated, pubmed-meshheading:17524578-Talc, pubmed-meshheading:17524578-Technology, Pharmaceutical, pubmed-meshheading:17524578-Transition Temperature, pubmed-meshheading:17524578-Water
pubmed:year
2007
pubmed:articleTitle
Crystal growth formation in melt extrudates.
pubmed:affiliation
College of Pharmacy, The University of Texas, Austin, TX 78712, United States. cdietzsch@mail.utexas.edu
pubmed:publicationType
Journal Article