Mechanism of release from pellets coated with an ethylcellulose-based film
dc.contributor.author | Ozturk, A. G. | en_US |
dc.contributor.author | Ozturk, Sadettin S. | en_US |
dc.contributor.author | Palsson, Bernhard Ø. | en_US |
dc.contributor.author | Wheatley, T. A. | en_US |
dc.contributor.author | Dressman, Jennifer B. | en_US |
dc.date.accessioned | 2006-04-10T13:32:27Z | |
dc.date.available | 2006-04-10T13:32:27Z | |
dc.date.issued | 1990-12 | en_US |
dc.identifier.citation | Ozturk, A. G., Ozturk, S. S., Palsson, B. O., Wheatley, T. A., Dressman, J. B. (1990/12)."Mechanism of release from pellets coated with an ethylcellulose-based film." Journal of Controlled Release 14(3): 203-213. <http://hdl.handle.net/2027.42/28280> | en_US |
dc.identifier.uri | http://www.sciencedirect.com/science/article/B6T3D-475TC1M-HC/2/1ed33e0c2ecb790c7e387eb268ed82ab | en_US |
dc.identifier.uri | https://hdl.handle.net/2027.42/28280 | |
dc.description.abstract | Studies were conducted to determine the mechanism of drug release from pellets coated with an ethylcellulose-based pseudolatex widely accepted for use as a sustained release coating for pharmaceuticals. Possible mechanisms for release include solution/diffusion through the continuous polymer phase and/or plasticizer channels, diffusion through aqueous pores and osmotically driven release through aqueous pores. To distinguish between these mechanisms, the release rate was studied as a function of coating thickness, plasticizer content, and osmotic pressure in the dissolution medium. As the coating thickness was increased from 9 to 50 [mu]m, the rate of release fell from 9.93[middle dot]10-3 to 1.71[middle dot]10-3 g phenylpropanolamine (PPA)[middle dot]HCl/100 ml h in an inversely proportional manner. Release as a function of plasticizer content was studied over the range 12 to 24% dibutyl sebacate (DBS). At 18 or 24% DBS, the rates of release of PPA[middle dot]HCl were virtually identical, about 50% of PPA[middle dot]HCl in six hours. At 12% DBS through, over 80% was released in the first hour. Surface area measurements and scanning electron microscopy (SEM) showed that the larger surface area of the 12% DBS batch was attributable to the presence of cracks in the coating. These results indicated that while the plasticizer is important in terms of forming a continuous film, diffusion through plasticizer channels is unlikely to make a significant contribution to the overall release rate. Release was also studied as a function of the osmotic pressure in the medium. A plot of release rate vs. osmotic pressure revealed an inverse linear relationship with a nonzero intercept. The steep dependency of release rate on osmotic pressure of the medium suggested that osmotically driven release is a major mechanism for release, while the nonzero intercept indicated some contribution from diffusion mechanisms. For all batches, SEM indicated that the film exhibited pores approximately 2 [mu]m in diameter, consistent with these mechanisms. In summary, then, the release from PPA[middle dot]HCl pellets coated with an ethylcellulose-based film appears to be a combination of osmotically driven release and diffusion through the polymer and/ or aqueous pores. A mathematical expression for this type of release is presented. | en_US |
dc.format.extent | 1059332 bytes | |
dc.format.extent | 3118 bytes | |
dc.format.mimetype | application/pdf | |
dc.format.mimetype | text/plain | |
dc.language.iso | en_US | |
dc.publisher | Elsevier | en_US |
dc.title | Mechanism of release from pellets coated with an ethylcellulose-based film | en_US |
dc.type | Article | en_US |
dc.rights.robots | IndexNoFollow | en_US |
dc.subject.hlbsecondlevel | Chemistry | en_US |
dc.subject.hlbsecondlevel | Biological Chemistry | en_US |
dc.subject.hlbtoplevel | Science | en_US |
dc.subject.hlbtoplevel | Health Sciences | en_US |
dc.description.peerreviewed | Peer Reviewed | en_US |
dc.contributor.affiliationum | Department of Chemical Engineering, The University of Michigan, Ann Arbor, MI 48109-1065, U.S.A. | en_US |
dc.contributor.affiliationum | Department of Chemical Engineering, The University of Michigan, Ann Arbor, MI 48109-1065, U.S.A. | en_US |
dc.contributor.affiliationum | Department of Chemical Engineering, The University of Michigan, Ann Arbor, MI 48109-1065, U.S.A. | en_US |
dc.contributor.affiliationum | College of Pharmacy, The University of Michigan, Ann Arbor, MI 48109-1065, U.S.A. | en_US |
dc.contributor.affiliationother | FMC Corporation, Princeton, NJ 08543, U.S.A. | en_US |
dc.description.bitstreamurl | http://deepblue.lib.umich.edu/bitstream/2027.42/28280/1/0000033.pdf | en_US |
dc.identifier.doi | http://dx.doi.org/10.1016/0168-3659(90)90160-U | en_US |
dc.identifier.source | Journal of Controlled Release | en_US |
dc.owningcollname | Interdisciplinary and Peer-Reviewed |
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