title: Oral suspensions of morphine hydrochloride for controlled release: rheological properties and drug release.
abstract: Recent developments in pharmaceutical technology have facilitated the design and production of modified release formulas for drugs whose physical, chemical or biological properties impede release and thus might compromise their efficacy or safety. One such drug is morphine, whose short half-life requires repeated doses at short intervals. The use of biocompatible polymers such as ethylcellulose has made it possible to develop microencapsulated formulations which facilitate liquid, sustained-release pharmaceutical formulas for oral administration. We developed a stable final formulation of morphine with an acceptable release profile by comparing the rheological properties and stability of formulations with different thickeners (xanthan gum, Carbopol, and carboxymethylcellulose with microcrystalline cellulose) at different concentrations from 0.25% to 1.0%. Release assays in a Franz-type cell were done to determine the most suitable release profile for the formulation.
authors.affiliation: Department of Pharmacy and Pharmaceutical Technology, School of Pharmacy, University of Granada, 18071 Granada, Spain.
authors.forename: M E
authors.initials: ME
authors.lastname: Morales
authors.forename: G
authors.initials: G
authors.lastname: López
authors.forename: V
authors.initials: V
authors.lastname: Gallardo
authors.forename: M A
authors.initials: MA
authors.lastname: Ruiz
mesh_terms: D000180:Acrylic Resins; D000284:Administration, Oral; D000701:Analgesics, Opioid / Q000008:administration & dosage; D002266:Carboxymethylcellulose Sodium / Q000737:chemistry*; D002482:Cellulose / Q000737:chemistry*; D003692:Delayed-Action Preparations / Q000378:metabolism*; D004339:Drug Compounding; D008567:Membranes, Artificial; D009020:Morphine / Q000008:administration & dosage*; D011135:Polysaccharides, Bacterial / Q000737:chemistry*; D011145:Polyvinyls / Q000737:chemistry*; D012212:Rheology; D013535:Suspensions
chemical_list: D000180:Acrylic Resins; D000701:Analgesics, Opioid; D003692:Delayed-Action Preparations; D008567:Membranes, Artificial; D011135:Polysaccharides, Bacterial; D011145:Polyvinyls; D013535:Suspensions; C006912:carboxypolymethylene; D009020:Morphine; D002482:Cellulose; D002266:Carboxymethylcellulose Sodium; C109691:microcrystalline cellulose; C002563:xanthan gum