title: In vivo characteristics of injectable poly(DL-lactic acid) microspheres for long-acting drug delivery.
abstract: Poly(DL-lactic acid) (PLA) microspheres containing testosterone (T) were prepared by the solvent evaporation process to evaluate their physical properties such as size distribution, shape, drug content, in vivo controlled drug release, pharmacological influences on the prostate gland in castrated rats, and histopathological findings of tissues surrounding the implants. The in vivo release of T from PLA microspheres containing 30 mg of drug obtained with chloroform was continued over a 6-week period. This effect is attributed to high dispersibility of T in the device when obtained with chloroform. Both serum drug levels and prostate gland weight recovery suggested the effects of a long-acting drug delivery system. The histopathological findings showed that the devices used were completely degraded 10 weeks after injection.
authors.affiliation: Department of Urology, Gunma University School of Medicine, Japan.
authors.forename: D
authors.initials: D
authors.lastname: Kobayashi
authors.forename: S
authors.initials: S
authors.lastname: Tsubuku
authors.forename: H
authors.initials: H
authors.lastname: Yamanaka
authors.forename: M
authors.initials: M
authors.lastname: Asano
authors.forename: M
authors.initials: M
authors.lastname: Miyajima
authors.forename: M
authors.initials: M
authors.lastname: Yoshida
mesh_terms: D000818:Animals; D003692:Delayed-Action Preparations; D016503:Drug Delivery Systems; D004343:Drug Implants; D007267:Injections; D019344:Lactic Acid; D008297:Male; D008863:Microspheres; D008970:Molecular Weight; D009919:Orchiectomy; D011091:Polyesters; D011108:Polymers; D011467:Prostate / Q000187:drug effects / Q000473:pathology; D051381:Rats; D017208:Rats, Wistar
chemical_list: D003692:Delayed-Action Preparations; D004343:Drug Implants; D011091:Polyesters; D011108:Polymers; D019344:Lactic Acid; C033616:poly(lactide)