567
Views
300
CrossRef citations to date
0
Altmetric
Review Article

Biodegradable poly(lactic acid) and poly(lactide-co-glycolide) microcapsules: problems associated with preparative techniques and release properties

&
Pages 297-325 | Received 19 Sep 1989, Accepted 11 Oct 1989, Published online: 27 Sep 2008

References

  • Anderson J. M., Niven H., Pelagalli J., Olanoff L. H., Jones R. D. The role of the fibrous capsule in the function of implanted dpug polymer sustained release systems. Journal of Biomedical Materials Research 1981; 15: 889–902
  • Asch R. H., Rojas F. J., Barter A., Schally A. V., Tice T. R., Klemcke H. G., Silerkhodr T. M., Bray R. E., Hogan M. P. Prolonged suppression of plasma LH-RH agonist in poly(D,L-lactide-co-glycolide) microcapsules. Journal of Andrology 1985; 6(2)83–88
  • Beck L. R., Cowsar D. R., Lewis D. H., Cosgrove R. J., Riddel C. T., Lowry S. L., Epperly T. A new long acting injectable microcapsule system for administration of progesterone. Fertilisation and Sterility 1979a; 31(5)545
  • Beck L. R., Cowsar D. R., Lewis D. H., Gibson J. W., Flowers C. E. New long acting injectable microcapsule contraceptive system. American Journal of Obstetrics and Gynecology 1979b; 135: 419
  • Beck L. R., Cowsar D. R., Pope V. Z. Injectable particulate contraceptive systems. Research Frontiers in Fertility Regulation, G. I. Zatuchini, M. H. Labbok, J. J. Sciarra. Harper and Row, London 1980a; 213–229
  • Beck L. R., Cowsar D. R., Pope V. Z. Systemic and local delivery of contraceptive steroids using biodegradable microcapsules. Biodegradation and Delivery Systems for Contraception, E. S. E. Hafez, W. A.A. Van Os. MTP Press, England 1980b; Vol. 1: 63–81
  • Beck L. R., Flowers C. E., Cowsar D. R. Microcapsules for treating the interior of female sexual organ, German patent, No. 29 40–146, 1980c
  • Beck L. R., Ramos R. A., Flowers C. E., Lopez G. Z., Lewis D. H., Cowsar D. R. Clinical evaluation of injectable biodegradable contraceptive system. American Journal of Obstetrics and Gynecology 1981; 140: 799–806
  • Beck L. R., Pope V. Z., Flowers C. E., Cowsar D. R., Tice T. R., Lewis D. H., Dunn R. L., Moore A. B., Gilley R. Poly(D,L-lactide-co-glycolide)/Norethisterone microcapsules: An injectable biodegradable contraceptive. Biology of Reproduction 1983a; 28(1)186–195
  • Beck L. R., Flowers C. E., Pope V. Z., Wilborn W. H., Tice T. R. Clinical evaluation of an improved injectable microcapsule contraceptive system. American Journal of Obstetrics and Gynecology 1983b; 147(7)815–821
  • Benagiano G., Gabelnick H. L. Biodegradable system for the sustained release fertility regulatory agents. Journal of Steroid Biochemistry 1979; 11: 449
  • Benita S., Benoit J. P., Puisieux F., Thies C. Characterization of drug loaded Poly(d,l-lactide) microspheres. Journal of Pharmaceutical Science 1984; 73(12)1721–1724
  • Benoit J. P., Benita S., Puisieux F., Thies C. Stability and release kinetics of drug incorporated within microspheres. Microsphere and Drug Therapy, Pharmaceutical, Immunological and Medical Aspects, S. S. Davis, L. Illum, J. G. McVie, E. Tomlinson. Elsevier, Amsterdam 1984; 95–102
  • Benoit J. P., Courteille F., Thies C. A physiochemical study of the morphology of progesterone loaded poly(d,l-lactide) microspheres. International Journal of Pharmaceutics 1986; 29: 95–102
  • Bissery M. C., Puisieux F., Thies C. A study of process parameters in the making of microspheres by solvent evaporation process. 3rd International Conference on Pharmaceutical Technology, Paris. 1983; Vol. III: 233–241
  • Bodmeier R., Chen H. Preparation of biodegradable poly ()lactide microparticles using a spray-drying technique. Journal of Pharmacy and Pharmacology 1988; 40: 754–757
  • Bodmeier R., McGinity J. W. The preparation and evaluation of drug poly(dl-lactide) on drug release from biodegradable poly(dl-lactide) drug delivery systems. International Journal of Pharmaceutics 1987a; 51: 1–8
  • Bodmeier R., McGinity J. W. The preparation and evaluation of drug containing poly(d,l-lactide) microspheres formed by the solvent evaporation. Pharmaceutical Research 1987a; 4: 465–471
  • Bodmeier R., McGinity J. W. Poly(lactic acid) microspheres containing quinidine base and quinidine sulphate prepared by the solvent evaporation technique. I. Methods and morphology. Journal of Microencapsulation 1987b; 4(4)279–288
  • Bodmeier R., McGinity J. W. Poly(lactic acid) microspheres containing quinidine base and quinidine sulphate prepared by solvent evaporation technique. II. Some process parameters influencing the preparation and properties of microspheres. Journal of Microencapsulation 1987c; 4(4)289–297
  • Bodmeier R., McGinity J. W. Poly(lactic acid) microspheres containing quinidine base and quinidine sulphate prepared by solvent evaporation method. III. Morphology of the microspheres during dissolution studies. Journal of Microencapsulation 1988; 5(4)325–330
  • Boswell G. A., Scribner R. M. Poly(lactide)-drug mixtures. U.S. Patent No. 3,773,919, 1973
  • Bradley W. G., Wilkes G. L. Some mechanical property consideration of reconstituted collagen for drug release supports. Biomaterials, Medical Devices and Artificial Organs 1977; 5: 159
  • Brady J. M., Cutright D. E., Miller R. A., Battistone G. C. Resorption rate, route of elimination and ultrastructure of the implant site of polylactic acid in the abdominal wall of the rat. Journal of Biomedical Materials Research 1973; 7: 155–166
  • Bruck S. D. Sterilisation problems of synthetic biocompatible materials. Journal of Biomedical Materials Research 1971; 5: 139–158
  • Cavalier M., Benoit J. P., Thies C. The formation and characterization of hydrocortisone loaded poly(d,l-lactide) microspheres. Journal of Pharmacy and Pharmacology 1986; 38: 249–253
  • Chu C. C. Degradation phenomena of two linear aliphatic polyester fibre used in medicine and surgery. Polymerization 1985; 26: 591–594
  • Cowsar D. R., Tice T. R., Gilley R. M., English J. Poly(lactide-co-glycolide) microcapsules for controlled release of steroids. Methods in Enzymology, K. J. Widder, R. Green. Academic Press Inc., New York 1985; Vol. 112: 101–116
  • Cutright D. E., Beasley J. D., Perez B. Histologic comparison of poly(lactic acid) and poly(glycolic acid) sutures. Oral Surgery 1971; 32: 165–173
  • Cutright D. E., Perez B., Beasley J. D., Larson W. J., Posey W. R. Degradation of poly(lactic acid) polymer and co-polymers of poly(glycolic acid). Oral Surgery 1974; 37: 142–152
  • Cutright D. E., Brady J. M., Miller R. A., Williams M. A. Degradation of poly(lactide-co-glycolide) co-polymers. Journal of Oral Medicine 1975; 30(1)5–7
  • Deasy P. B. Microencapsulation and related drug process. Marcel Dekker, Inc., New York 1984; 361
  • Desai S. J., Simonelli A. P., Higuchi W. I. Investigation of factors influencing release rate of solid drug dispersed in inert matrices. Journal of Pharmaceutical Science 1965; 54: 1459–1464
  • Dunn R. L., English J. P., Strobel J. D., Cowsar D. R., Tice T. R. Preparation and evaluation of lactide/glycolide co-polymers for drug delivery. Polymers in Medicine. III, Migliaresi, et al. Elsevier Science Publishers, Amsterdam 1988; 149–160
  • Folkman J., Long D. M. The use of silicone rubber as a carrier for prolonged drug therapy. Journal of Surgical Research 1964; 4(3)139–142
  • Fong J. W. Process for preparation of microcapsules. U.S. Patent no. 4,166,800, 1979
  • Fong J. W. Process of preparation of microspheres. U.S. Patent. 4,384,975, 1983
  • Fong J. W. Process for preparation of microspheres and modification of release rate of core material. U.S. Patent no. 4,479,911, 1984
  • Fong J. W. Microencapsulation by solvent evaporation and organic phase separation process. Controlled release systems: Fabrication technology, D. Hsiesh. CRC Press Inc., Florida 1988; vol. 1: 81–108
  • Fong J. W., Nazareno J. P., Pearson J., Maulding H. V. Evaluation of biodegradable microcapsules prepared by solvent evaporation process using sodium oleate as emulsifier. Journal of Controlled Release 1986; 3: 119–130
  • Fong J. W., Maulding H. V., Visscher G. E., Nazareno J. P., Pearson J. E. Enhancing drug release from poly(lactide) microspheres by using base in the microencapsulation process. Controlled release technology. Pharmaceutical Applications, P. Lee, W. R. Good. American Chemical Society, Washington, DC 1987; 214–231
  • Fujimoto S., Endoh F., Kitsukawa Y., Okui K., Morimoto Y., Sugibayashi K., Mikayakawa A., Suzuki H. Continued in vitro and in vivo release of an anticancer drug from albumin microspheres. Experientia 1981; 39: 913–916
  • Gilding D. K., Reed A. M. Biodegradable polymers for use in surgery. Poly(glycolic)/Poly(lactic acid) homo and copolymers. Polymer 1979; 20: 1459–1464
  • Goosen M. F., Leung Y. F., O'Shea G. M. Long acting insulin. Slow release of insulin from a biodegradable matrix implanted in diabetic rats. Diabetes 1983; 32(51)478–481
  • Gurny R., Peppas N. A., Harrington D. D., Banker G. S. Development of biodegradable and injectable latices for controlled release of potent drugs. Drug Development and Industrial Pharmacy 1981; 7(1)1–25
  • Hashida M., Takahashi Y., Muranishi S., Sezaki H. An application of water in oil and gelatin microsphere-in-oil emulsion to specific delivery of anticancer agent in stomach lymphatics. Journal of Pharmacokinetic Biopharmacy 1977; 5: 241
  • Higuchi T. Rate of release of medicaments from ointment base containing drugs in suspension. Journal of Pharmaceutical Science 1961; 50(10)874–875
  • Higuchi T. Mechanism of sustained action medication. Theoretical analysis of rate of release of solid drugs dispersed in solid matrices. Journal of Pharmaceutical Science 1963; 52(12)1145–1149
  • Hutchinson F. G., Furr B. J. A. Biodegradable carriers for the sustained release of polypeptides. Trends in Biological Technology 1987; 5: 102–106
  • Jackanicz T. M., Nash H. A., Wise D. L., Gregory J. B. Poly(lactic acid) as a biodegradable carrier for contraceptive steroids. Contraception 1973; 8: 227–234
  • Jalil R., Nixon J. R. Preparation, characterization and release properties of phenobarbitone from poly(l-lactic acid) microspheres. Proceedings of the 5th International Conference on Pharmaceutical Technology, Paris, 1989a; Vol. V: 94–103
  • Jalil R., Nixon J. R. Microencapsulation using poly(l-lactic acid). I: Microcapsule properties affected by the preparative technique. Journal of Microencapsulation 1989b; 6(4)473–484
  • Jalil R., Nixon J. R. Microencapsulation using poly (L-lactic acid). II. Preparative variables affecting microcapsule properties. Journal of Microencapsulation 1990a; 7(1)25–39
  • Jalil R., Nixon J. R. Microencapsulation using poly(l-lactic acid). III. Effect of polymer molecular weight on the microcapsule properties. Journal of Microencapsuation 1990b; 7(1)41–52
  • Jalil R., Nixon J. R. Microencapsulation using poly(l-lactic acid). IV. Release properties of microcapsules containing phenobarbitone. Journal of Microencapsulation 1990c; 7(1)53–66
  • Jalil R., Nixon J. R. Microencapsulation using poly(dl-lactic acid), I. Effect of preparative variables on the microcapsule characteristics and release kinetics. Journal of Microencapsulation 1990d; 7(2)229–244
  • Jalil R., Nixon J. R. Microencapsulation using poly(dl-lactic acid). III. Effect of polymer molecular weight on the release kinetics. Journal of Microencapsulation 1990e; 7(3)357–374
  • Juni K., Ogata J., Nakano M., Ichihara T., Mori K., Akagi M. Preparation and evaluation in vitro and in vivo of Poly(lactic acid) microspheres containing doxorubicin. Chemistry and Pharmacy Bulletin 1985a; 33(1)313–318
  • Juni K., Ogata J., Matsui N., Kubota M., Nakano M. Control of release rate of bleomycin from poly(lactic acid) microspheres by additives. Chemistry and Pharmacy Bulletin 1985b; 33(4)1609–1614
  • Kent J. S., Sanders L. M., Tice T. R., Lewis D. H. Microencapsulation of the peptide nafarelin acetate for controlled release. Long Acting Contraceptive Delivery Systems, G. I. Zatuchni, A. Goldsmith, J. D. Sheton, J. J. Seuarra. Harper and Row, Philadelphia 1982; 169–179
  • Kitchell J. P., Wise D. L. Poly(lactic/glycolic acid) biodegradable drug polymer matrix systems. Methods in Enzymology, K. J. Widder, R. Green. Academic Press Inc., New York 1985; Vol. 112: 436–448
  • Kondo A. Microencapsulation Processing and Technology, J. Ade Van Valkenburg. Marcel Dekker Inc., New York 1979
  • Krause H.-J., Schwarz A., Rohdewald P. Poly(lactic acid) nanoparticles, a colloidal drug delivery system for lipophilic drugs. International Journal of Pharmaceutics 1985; 27: 145–155
  • Kulkarni R. K., Pani K. C., Neuman C., Leonard F. Poly(lactic acid) for surgical implants. Archives of Surgery 1966; 93: 839–843
  • Kulkarni R. K., Moore E. G., Hegyeli A. F., Leornard F. Biodegradable poly(lactic acid) polymers. Journal of Biomedical Materials Research 1971; 5: 169–181
  • Leelarasamee N., Howard S. A., Malanga C. J., Luzzi L. A., Hogan T. F., Kandzari S. J., Ma J. K. H. Kinetics of drug release from poly(lactic acid) - hydrocortisone microcapsules. Journal of Microencapsulation 1986; 3(3)171–179
  • Leelarasamee N., Howard S. A., Ma J. K. H. Effect of surface active agents on drug release from poly(lactic acid)-hydrocortisone microcapsules. Journal of Microencapsulation 1988a; 5(1)37–46
  • Leelarasamee N., Howard S. A., Malanga C. J., Ma J. K. H. A method for the preparation of poly(lactic acid) microcapsules of controlled particle size and drug loading. Journal of Microencapsulation 1988b; 52(2)147–157
  • Luzzi L. A. Encapsulation techniques for pharmaceuticals: Considerations for the microencapsulation of drugs. Microencapsulation, J. R. Nixon. Marcel Dekker, Inc., New York 1976; 193–206
  • Luzzi L. A., Palmieri A. An overview of pharmaceutical applications. Biomedical Applications of Microencapsulation, F. Lim. CRC Press Inc., Florida 1984; 1–17
  • Makino K., Arakawa M., Kondo T. Preparation and in vitro degradation properties of poly(lactide) microcapsules. Chemistry and Pharmacy Bulletin 1985; 33(3)1195–1201
  • Makino K., Ohshima H., Kondo T. Mechanism of hydrolytic degradation of poly(l-lactide) microcapsules: Effect of pH, ionic strength, and buffer concentration. Journal of Microencapsulation 1986; 3(3)203–212
  • Mason N. S., Thies C., Cicero T. J. In vivo and in vitro evaluation of a microencapsulated narcotic antagonist. Journal of Pharmaceutical Science 1976; 65: 847–850
  • Mason N. S., Gupta D. V. S., Keller D. W., Youngquist R. S., Sparks R. F. Microencapsulation of progesterone for contraception by intracervical injection. Biomedical Applications of Microencapsulation, F. Lim. CRC Press Inc., Florida 1984; 75–84
  • Maulding H. V. Prolonged delivery of peptides by microcapsules. Advances in Drug Delivery Systems, J. M. Anderson, S. W. Kim. Elsevier Sci. Pub., Amsterdam 1987; 3: 167–176
  • Maulding H. V., Tice T. R., Cowsar D. R., Fong J. W., Pearson J. E., Nazapeno J. P. Biodegradable microcapsules: acceleration of polymeric excipient hydrolytic rate by incorporation of a basic medicament. Journal of Controlled Release 1986; 3: 103–106
  • Michaels A. S. Bioerodible occular drug delivery systems. U.S. Patent. 3,962,414, 1976
  • Miller R. A., Brady J. M., Cutright D. E. Degradation rates of ora reabsorbable implants (PLA-PGA), rate modified with change in poly(lactide-co-glycolide) copolymer ratios. Journal of Biomedical Materials Research 1977; 11: 711–719
  • Morimoto Y., Sugibayashi K., Kato Y. Drug carrier property of albumin microspheres in chemotherapy. V. Antitumor effect of microspheres entrapped adriamycin on liver metastasis of AH 7974 cells in rats. Chemistry and Pharmacy Bulletin 1981; 29: 1433–1438
  • Nakano M., Itoh M., Juni K., Sekikawa H., Arita T. Sustained urinary excretion of sulfamethizole following oral administration of enteric coated microcapsules in humans. International Journal of Pharmaceutics 1980; 4: 291–298
  • Ogawa Y., Yamamoto M., Takada S., Shimamoto T. Controlled release of leuprolide acetate from polylactic acid or copoly(lactic/glycolic) acid microcapsules: influence of molecular weight and co-polymer ratio of polymer. Chemistry and Pharmacy Bulletin 1988a; 36: 1502–1507
  • Ogawa Y., Okada H., Yamamoto M., Shimamoto T. In vivo release profiles of leuprolide acetate from microcapsules prepared with polylactic acids or copoly(lactic/glycolic) acids and in vivo degradation of these polymers. Chemistry and Pharmacy Bulletin 1988b; 36: 2567–2581
  • Ogawa Y., Yamamoto M., Okada H., Yashiki T., Shimamoto T. A new technique of efficiently entrapped leuprolide acetate into microcapsules of polylactic acid or copoly(lactic/glycolic) acid. Chemistry and Pharmacy Bulletin 1988c; 36: 1095–1103
  • Ogawa Y., Okada H., Heya T., Shimamoto T. Controlled release of LHRH agonist, leuprolide acetate, from microspheres: serum drug level profiles and pharmacological effects in animals. Journal of Pharmacy and Pharmacology 1989; 41: 439–444
  • Pitt C. G., Jeffcoat A. R., Zweidinger R. A., Schinkler A. Sustained drug delivery systems-I. The permeability of poly(-caprolactone, poly(d,l-lactic acid) and their copolymers. Journal of Biomedical Materials Research 1979a; 13: 497
  • Pitt C. G., Gratsl M. M., Jeffcoat A. R., Zweidinger R., Schindler A. Sustained drug delivery systems-II. Factors affecting release rates from poly (-caprolactone) and related biodegradable polyesters. Journal of Pharmaceutical Science 1979b; 68(12)1534–1538
  • Rack J., Ford J. L., Rostron Ch., Walters V. The preparation and characterization of poly(D,L-lactic acid) as a biodegradable drug carrier. Pharmaceutica Acta Helvetica 1985; 60(5–6)162–169
  • Ratcliffe J. H., Honneybalu I. M., Smith A., Wilson C. G., Davis S. S. Preparation and evaluation of biodegradable polymeric systems for the intra-articular delivery of drugs. Journal of Pharmacy and Pharmacology 1984; 36(7)431–436
  • Rubin A. L., Stenzel K. H., Miyata T., White M. J., Dunn M. Collagen as a vehicle for drug delivery. Journal of Clinical Pharmacology 1973; 14: 309
  • Ruiz J. M., Tissier B., Benoit J. P. Microencapsulation of peptide: a study of the phase separation of poly(DL-lactic acid-co-glycolic acid) co-polymers, 50 50, by silicone oil. International Journal of Pharmaceutics 1989; 49: 69–77
  • Sanders L. M., Kent J. S., MaCrae G. I., Vickery B. H., Tice T. R., Lewis D. H. Controlled release of Leutinizing hormone releasing hormone analogue from poly(d,l-lactide-co-glycolide) microspheres. Journal of Pharmaceutical Science 1984; 73(9)1294–1297
  • Sanders L. M., McRae G. I., Vitale K. M., Kell B. A. Microencapsulation of LH-RH analogue using biodegradable polymers. Journal of Controlled Release 1985; 2: 187–195
  • Sanders L. M., McRae G. I., Vitale K. M., Kell B. A. Controlled delivery of an LH-RH analogue from biodegradable injectable microspheres. Advances in Drug Delivery Systems. Controlled Release Series, J. M. Anderson, S. W. Kim. Elsevier Sci Pub., Amsterdam 1986; Vol. I: 186–195
  • Sato T., Kanke M., Schroedeer H. G., DeLuca P. P. Porous biodegradable microspheres for controlled drug delivery, I. Assessment of processing conditions and solvent removal techniques. Pharmaceutical Research 1988; 5(1)21–30
  • Shell J. W. Ocular systems made of bioerodible ester having linear ether. U.S. Patent no. 4,115,544, 1978
  • Smith A., Hunneyball I. M. Evaluation of poly(lactic acid) as a biodegradable drug delivery system for parenteral administration. International Journal of Pharmaceutics 1986; 30: 215–220
  • Sparks R. E., Gupta D. V. S., Keller D. W., Mason N. S. Microencapsulation of progesterone for contraception by intracervical injection. Supplement of Proceedings of the 4th International Symposium on Microencapsulation, Florida, March, 26–301979, 7
  • Speiser P., Hijnsbroek R. Micropellets in a biodegradable carrier. German Patent. 2,824,112, 1979, Dec., Chemical Abstracts 92, 135447w.
  • Spenlehauer G., Veillard M., Benoit J. P. Formation and characterization of cisplatin loaded poly(d,l-lactide) microspheres for chemoembolization. Journal of Pharmaceutical Science 1986; 75: 750–755
  • Suzuki K., Price J. C. Microencapsulation and dissolution properties of neuroleptic in a biodegradable polymer, poly(d,l-lactide). Journal of Pharmaceutical Science 1985; 74(1)21–24
  • Tatum H. J. Fertility control and acceptability in women of contraceptive steroids, released in microquantities from subcutaneous silastic capsules. Contraception 1970; 1(4)253–263
  • Thies C. Characterization of microcapsules containing naltrexone or naltrexone pamoate. Controlled Release Polymeric Formulation, D. R. Paul, F. W. Harris. American Chemical Society. 1976; 190–194
  • Thies C. Microencapsulation. New Techniques and Application, T. Kondo. Techno Books. 1979; 143–148
  • Thies C., Bissery M. C. Biodegradable microcapsules for parenteral administration. Biomedical Application of Microencapsulation, Franklin Lim. CRC Press Inc., Florida 1984; 53–74
  • Tice T. R. Long acting biodegradable steroid microcapsules for parenteral administration. Polymer Reprints 1985; 26(2)198–199
  • Tice T. R., Cowsar D. R. Biodegradable controlled release parenteral systems. Pharmaceutical Technology 1984; 8(11)26
  • Tice T. R., Gilley R. M. Preparation of injectable controlled release microcapsules by solvent evaporation process. Journal of Controlled Release 1985; 2: 343–352
  • Tice T. R., Lewis D. H. Microencapsulation process. U.S. Patent. 4,389,330, 1983
  • Tsai D. C., Howard S. A., Hogan T. F., Malanga C. J., Kandzari S. J., Ma J. K. H. Preparation and in vitro evaluation of poly(lactic acid)/mitomycin-c microcapsules. Journal of Microencapsulation 1986; 3(3)181–193
  • Uno K., Ohara Y., Arakawa M., Kondo T. Preparation of polylactic acid microcapsules with water using interfacial deposition technique. Journal of Microencapsulation 1984; 1: 3
  • Vidmar V., Smolcic-Bubalo A., Jalsenjak I. Poly(lactic acid) microencapsulated oxytetracycline: in vitro and in vivo evaluation. Journal of Microencapsulation 1984; 1(2)131–136
  • Vidmar V., Pepeljnjak S., Jalsenjak I. The in vivo evaluation of poly(lactic acid) microcapsules of pilocarpine hydrochloride. Journal of Microencapsulatio 1985; 2(4)289–292
  • Visscher G. E., Robinson R. L., Maulding H. V., Fong J. W., Pearson J. E., Argentieri G. J. Biodegradation and tissue reaction to 50:50 poly(D,L-lactide-co-glycolide) microcapsules. Journal of Biomedical Materials Research 1985; 19(3)349–365
  • Visscher G. E., Robinson R. L., Maulding H. V., Fong J. W., Pearson J. E., Argentieri G. J. Biodegradation and tissue reaction poly(D,L-lactide) microcapsules. Journal of Biomedical Materials Research 1986; 20: 667–676
  • Wakiyama N., Juni K., Nakano M. Preparation and evaluation in vitro of poly(lactic acid) microspheres containing local anaesthetics. Chemistry and Pharmacy Bulletin 1981; 29(11)3363–3368
  • Wakiyama N., Juni K., Nakano M. Influence of physiochemical properties of poly(lactic acid) on the characteristics and in vitro release patterns of poly(lactic acid) microspheres containing local anaesthetics. Chemistry and Pharmacy Bulletin 1982a; 30(7)2621–2628
  • Wakiyama N., Juni K., Nakano M. Preparation and evaluation in vitro and in vivo of poly(lactic acid) microspheres containing dibucaine. Chemistry and Pharmacy Bulletin 1982b; 30(10)3719–3727
  • Widder K. J., Flouret G., Senyei A. E. Magnetic microspheres: synthesis of a novel parenteral drug carrier. Journal of Pharmaceutical Science 1979; 68: 79–82
  • Widder K. J., Senyei A. E., Ranney D. In vitro release of biologically active adriamycin by magnetically responsive albumin microspheres. Cancer Research 1980; 40: 3512–3517
  • Widder J. K., Senyei A. E., Sears B. Experimental methods in cancer therapeutics. Journal of Pharmaceutical Science 1982; 71(4)379–387
  • Willmot N., Cummings J., Florence A. T. In vitro release of adriamycin from drug loaded albumin and haemoglobin microspheres. Journal of Microencapsulation 1985; 2(4)293–304
  • Wise D. L., McCormick G. J., Willet G. P., Anderson L. C. Sustained release of an antimalarial drug using a co-polymer of glycolic/lactic acid. Life Sciences 1976; 19: 867–874
  • Wise D. L., McCormic G. L., Willet G. P., Anderson L. C., Howes J. F. Sustained release of sulphadiazine. Journal of Pharmacy and Pharmacology 1978a; 30: 686–689
  • Wise D. L., Gregory J. B., Newberne P., Bartholow L. C., Stanbury H. B. Results on biodegradable cylindrical subdermal implants for fertility control. Polymeric Delivery Systems, R. J. Kostelnik. Gordon and Breach Sci. Pub., New York 1978b; 121–136
  • Wise D. L., Fellmann T. D., Sanderson J. E., Wentworth W. R. Lactic/glycolic acid polymers. Drug Carriers in Biology and Medicine, G. Gregoriadis. Academic Press, New York 1979; 237–270
  • Wise D. L., Rosenkrantz H., Gregory J. B., Esber H. J. Long-term controlled delivery of levonorgestrel in rats by means of small biodegradable cylinders. Journal of Pharmacy and Pharmacology 1980; 32: 399–403
  • Yolles S., Eldridge J. E., Woodland J. H. R. Sustained delivery of drugs from polymer drug mixtures. Polymer News 1971; 1: 9
  • Yolles S., Leafe T. D., Ward L., Boettner F. Controlled release of biologically active drugs. Bulletin of the Parenteral Drug Association 1976; 30(6)306–309
  • Yolles S., Leafe T. D., Woodland J. H. R., Meyer F. J. Long acting delivery systems for narcotic antagonists. II. Release rates of naltrexone from poly(lactic acid composites. Journal of Pharmaceutical Sciences 1975a; 64(2)348–349
  • Yolles S., Leafe T., Mayer F. J. Timed release depot for anticancer agents. Journal of Pharmaceutical Sciences 1975b; 64(1)115–116
  • Yoshioka T., Hashida M., Muranishi S., Sezaki H. Specific delivery o mitomycin-c to the liver, spleen, and lung: nano and microspherical carriers of gelatin. International Journal of Pharmaceutics 1981; 8(2): 131
  • Zhou M. X., Chang T. M. S. Control release of prostaglandin E2 from poly(lactic acid) microcapsules, microparticles, and modified microparticles. Journal of Microencapsulation 1988; 5(1)27–36
  • Zolle I., Rhodes B. A., Wagner H. N., Jr. Preparation of metabolizable radioactive human albumin microspheres for studies of circulation. International Journal of Applied Radiation and Isotopes 1970; 21: 155

Reprints and Corporate Permissions

Please note: Selecting permissions does not provide access to the full text of the article, please see our help page How do I view content?

To request a reprint or corporate permissions for this article, please click on the relevant link below:

Academic Permissions

Please note: Selecting permissions does not provide access to the full text of the article, please see our help page How do I view content?

Obtain permissions instantly via Rightslink by clicking on the button below:

If you are unable to obtain permissions via Rightslink, please complete and submit this Permissions form. For more information, please visit our Permissions help page.