4 edition of Rate of solvent evaporation and solubility parameter effects on microencapsulation found in the catalog.
Advisor: Nairn, J.G.Thesis (Ph.D.)--University of Toronto, 1994
|The Physical Object|
|Pagination||xvi, 91 p. :|
|Number of Pages||76|
nodata File Size: 4MB.
Res Pharm Sci 2010; 5 2 : 65-77. Variables influencing the drug entrapment efficiency of microspheres: A pharmaceutical review.
Theophylline TH was chosen as a model drug.
Young and Nelson equation can be used to explain the sorption and desorption profile of different viscosity grades of HPMC polymers. Similar results were obtained in an experiment where the effect of surfactants like span 80 and span 20 on particle sizes and entrapment efficiency of tramadol loaded PCL microspheres were studied. Mechanical processes include the air-suspension method, pan coating, and spray drying, spray congealing, micro-orifice system and rotary fluidization bed granulator method.
It has been observed that at the same amount of polymer in the micro spherical system, the polymers of higher viscosity are difficult to dissolve. The intracellular uptake ability of chitosan-coated Poly D,L-lactide-co-glycolide nanoparticles. Investigation of the influence of mean HPMC particle size and number of polymer particles on the release of aspirin from swellable hydrophilic matrix tablets.
open-access license: This is an open access article licensed under the terms of the Creative Commons Attribution-Non-Commercial 4. It has been observed and widely accepted that an increase in the polymer concentration increases the entrapment of the drug inside the micro and nanospherical systems. Microspheres were especially useful for delivery of moderately non-polar active ingredients but can be formulated to deliver very soluble polar compounds.
When the low molecular weight of lactic acid-glycolic acid polymer fraction 8,000 to about 15,000 is contained in a large amount, LHRH derivative readily interacts with these polymers of high reactivity or otherwise to produce a sustained-release composition which comprises emulsifying an aqueous solution containing LHRH derivative and an acid or a base with a solution of a biodegradable polymer Rickey et al.
Diffusion Diffusion is the most commonly involved mechanism wherein the dissolution fluid penetrates the shell, dissolves the core and leak out through the interstitial channels or pores.
Microspheres are in strict sense, spherically empty particles.
Thus, the drug loss due to diffusion from the gel layer also decreases.