Formation of porous membranes for drug delivery systems

Witte, P. van de; Esselbrugge, H.; Loman-Peters, A.M.P.; Dijkstra, Pieter J.; Schakenraad, Jm; Eenink, M.J.D.; Sam, Abbas

doi:10.1016/0168-3659(93)90168-5

Cited by 38 publications

(24 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Inside the microspheres, however, both the lidocaine‐free and ‐loaded microspheres displayed porous structures, as observed by SEM (data not shown). Formation of such porous structures could be accounted for by the occurrence of a phase separation in the PLA‐dissolving organic phase that was driven by a solvent (methylene chloride)–nonsolvent (water) exchange process; a phenomenon discussed previously by Witte and coworkers 17…”

Section: Resultsmentioning

confidence: 92%

Injectable microparticle‐gel system for prolonged and localized lidocaine release. I. In vitro characterization

Chen

Park

Chang

et al. 2004

J Biomedical Materials Res

View full text Add to dashboard Cite

Current treatment protocol for postoperative pain is to infuse anesthetic solution around nerves or into the epidural space. This clinical practice is beset by the short duration of the anesthetic effect unless the infusion is continuous. Continuous infusion, however, requires hospitalization of the patients, thereby increasing medical costs. In addition, it also causes systemic accumulation of the drug. We reported herein a novel treatment for the postoperative pain by applying to the surgical site a biodegradable microsphere-gel system for prolonged and localized release of encapsulated anesthetic drugs. This lidocaine-containing biodegradable poly(D,L-lactic acid) (PLA) microsphere system, although being established previously by other investigators, was hindered by a burst release and a followed rapid release of the drug within several hours in vitro. In this article, we demonstrated that by a step-by-step modification of the formulation, prolonged release of lidocaine, up to several days in vitro, could be achieved. Differential scanning calorimetry revealed a lower glass transition temperature for these lidocaine-loaded microspheres comparing to that of lidocaine-free microspheres. This decreased Tg explained for the tendency of the lidocaine-loaded microspheres to physically fuse at higher temperatures. In vitro studies showed that microspheres, when loaded with 35% lidocaine, yielded a threefold increase in the degradation rate. The molecular weight of PLA of the drug-loaded microspheres was reduced by 50% within a period of 1 month. Based on the results (of prolonged lidocaine release and rapid PLA microsphere degradation), this lidocaine-loaded PLA microsphere system could offer a simple solution to the treatment of postoperative pain.

show abstract

Section: Resultsmentioning

confidence: 92%

Injectable microparticle‐gel system for prolonged and localized lidocaine release. I. In vitro characterization

Chen

Park

Chang

et al. 2004

J Biomedical Materials Res

View full text Add to dashboard Cite

show abstract

“…20,21 PLA films were formed by means of immersion precipitation, which has, for instance, not only been proposed as a method for the preparation of biodegradable scaffolds for blood vessels, but also for preparation of drug delivery devices. 18 Two types of PLA were used: poly(D50,L50)lactide PDLLA and (P(L)LA) PLLA. PDLLA is a random copolymer that cannot crystallize and thus is either in the rubbery or in the glassy state, while PLLA is in optically pure form and crystallizes readily.…”

Section: Introductionmentioning

confidence: 99%

“…Obviously, the resulting morphology strongly depends on the type of additive and the interactions with the polymer, solvent, and nonsolvent. 13,[16][17][18][19] In the study reported here, we chose polylactic acid (PLA), which is a biodegradable polymer that has wide applications in the medical and pharmaceutical fields. 20,21 PLA films were formed by means of immersion precipitation, which has, for instance, not only been proposed as a method for the preparation of biodegradable scaffolds for blood vessels, but also for preparation of drug delivery devices.…”

Section: Introductionmentioning

confidence: 99%

Polylactide films formed by immersion precipitation: Effects of additives, nonsolvent, and temperature

Sawalha

Schroën

Boom

2007

J of Applied Polymer Sci

View full text Add to dashboard Cite

The influence of nonsolvent, crystallinity of the polymer film, and addition of dodecane (a poor solvent for the polymer and for the nonsolvent) on the morphology of polylactides films has been investigated and was related to phase separation behavior. Both amorphous poly-DL-lactide (PDLLA) and crystalline poly-L-lactide (PLLA) were dissolved in dichloromethane, and subsequently films were made by immersion in nonsolvent baths. PDLLA gave dense films without any internal structure, since the structure was not solidified by crystallization or glassification. PLLA films show varying structure depending on the nonsolvent. With methanol, asymmetric morphologies were observed as a result from combined liquid-liquid demixing and crystallization, while with water symmetric spherulitic structures were formed. As a next step, dodecane was added, which is not miscible with the nonsolvent, and we found it to have a strong influence on the morphology of the films. The PDLLA films with dodecane did not collapse: a closed cell structure was obtained. In PLLA films, dodecane speeds up phase separation and induces faster crystallization in the films, and the porosity, size of the pores, and interconnectivity increased. When the PLLA solutions were subjected to a heat pretreatment, crystallization could be postponed, which yielded a cellular structure around dodecane, which did not contain spherulites anymore. 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: [959][960][961][962][963][964][965][966][967][968][969][970][971] 2007

show abstract

“…He has also investigated the release of proteins and macromolecules from albumin-heparin microspheres [53,54], synthesis and biodistribution of immuno-conjugates of a human IgM [51], heparin release from thermosensitive hydrogels [55,56], and delivery of antibacterial proteins from gelatin-chondroitin sulfate hydrogels [57]. He has prepared and explored porous membranes for drug delivery [58], studied the biological properties of adriamycin bound to biodegradable polymeric carriers [49,51], and developed albumin-heparin conjugate microspheres for loading and release of adriamycin [31,59]. These adriamycin-loaded albumin-heparin conjugate microspheres were applied for intraperitoneal chemotherapy [60].…”

mentioning

confidence: 98%

Professor Jan Feijen: A pioneer in biomedical polymers and controlled drug release

Zhong

2015

Journal of Controlled Release

View full text Add to dashboard Cite

Formation of porous membranes for drug delivery systems

Cited by 38 publications

References 19 publications

Injectable microparticle‐gel system for prolonged and localized lidocaine release. I. In vitro characterization

Injectable microparticle‐gel system for prolonged and localized lidocaine release. I. In vitro characterization

Polylactide films formed by immersion precipitation: Effects of additives, nonsolvent, and temperature

Professor Jan Feijen: A pioneer in biomedical polymers and controlled drug release

Contact Info

Product

Resources

About