Controlled Drug Release from Monolithic Systems
Controlled drug release from monolithic systems can be achieved by diffusion, swelling, or erosion. In diffusion-controlled systems the drug is dissolved or dispersed in a polymer matrix and allowed to diffuse from the monolith. In swelling-controlled systems the drug is immobilized in a glassy, hydrophilic polymer and is released as a swelling front moves into the matrix. In chemically controlled systems, rate of drug release is controlled by a combination of diffusion and erosion or in special cases, by erosion alone.
KeywordsDrug Release Maleic Anhydride Release Kinetic Control Drug Release Polymer Hydrolysis
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- Beck LR, Ramos RA, Flowers CE Jr., Lopez GZ, Lewis DH, Cowsar DR (1981) Clinical evaluation of injectable biodegradable contraceptive systems. Am. J. Obstet. Gynecol. 140: 799–806Google Scholar
- Beck LR, Flowers CE Jr., Pope VZ, Wilborn WH, Tice TR (1983) Clinical evaluation of an improved injectable microcapsule contraceptive system. Am. J. Obstet. Gynecol. 147: 815–821Google Scholar
- Frazza EJ, Schmitt EE (1971) A new absorbable suture. J. Biomed. Mater. Res. Symp. 1: 43–58Google Scholar
- Heller J, Baker RW, Gale RM, Rodin JO (1978) Controlled drug release by polymer dissolution I. Partial esters of maleic anhydride copolymers. Properties and theory. J. Appl. Polymer Sci. 22: 1991–2009Google Scholar
- Heller J, Penhale DWH, Helwing RF (1980) Preparation of poly(ortho esters) by the reaction of ketene acetals and polyols. J. Polymer Sci., Polymer Lett. Ed. 18: 619–624Google Scholar
- Heller J (1984) Biodegradable polymers in controlled drug delivery. CRC Critical Reviews in Therap. Drug Carrier Syst. 1: 39–90Google Scholar
- Heller J, Penhale DWH, Fritzinger BK, Ng SY (1984) Controlled release of contraceptive agents from poly(ortho esters). In: Zatuchni GK, Goldsmith A, Shelton JD, Sciarra J (eds): Long acting contraceptive delivery systems. Harper and Row, Philadelphia; pp 113–128Google Scholar
- Heller J, Penhale DWH, Fritzinger BK, Ng SY (1987) The effect of copolymerized 9,10-dihydroxystearic acid on erosion rates of poly(ortho esters). J. Controlled Release, in pressGoogle Scholar
- Kulkarni RK, Pani KC, Neuman C, Leonard F (1966) Polylactic acid for surgical implants. Arch. Surg. 93: 839–843Google Scholar
- Langer R, Peppas N (1983) Chemical and physical structure of polymers as carriers for controlled release of bioactive agents: a review. Rev. Macromol. Chem. Phys. C23: 61–126Google Scholar
- Leong KW, Brott BC, Langer R (1985) Bioerodible polyanhydrides as drug-carrier matrices I: characterization, degradation, and release characteristics. J. Biomed. Mater. Res. 19: 941–955Google Scholar