title: Evaluation of PLGA microspheres as delivery system for antitumor agent-camptothecin.
abstract: Camptothecin (CPT) and its analogues are a new class of anticancer agents that have been identified over the past several years. Camptothecin exists in two forms depending on the pH: An active lactone form at pH below 5 and an inactive carboxylate form at basic or physiological neutral pH. Poly(lactide-co-glycolide) (PLGA) microspheres have been considered good delivery vehicles for CPT because of acidic microenvironment formed through PLGA degradation. The objective of this study is to investigate antitumor activity of CPT after it is encapsulated in PLGA microspheres. In this study, PLGA microspheres containing various CPT loadings were prepared and characterized. Cytotoxicity of these microspheres to B16 melanoma cells was then evaluated, and uptake of microspheres by B16 cells was also studied. Analysis of drug stability revealed that CPT is released from the microspheres in its active lactone form over the entire release duration. It was also found that there was no interaction between CPT and PLGA matrix within microspheres through Differential Scanning Calorimetry (DSC) and Fourien Transform Infrared Spectroscopy (FT-IR) and hign performance liquid chromatography (HPLC) studies. Cytotoxicity assay showed that CPT encapsulated in PLGA microspheres still retained its antitumor potency. Uptake study revealed quick uptake of the microspheres by B16 cells, which was desirable. It was concluded that PLGA microspheres were suitable delivery vehicles to stabilize and deliver CPT for the treatment of cancer.
authors.affiliation: Department of Pharmaceutical Sciences, Southern School of Pharmacy, Mercer University, Atlanta, Georgia 30341, USA.
authors.forename: Wenkai
authors.initials: W
authors.lastname: Tong
authors.forename: Lejun
authors.initials: L
authors.lastname: Wang
authors.forename: Martin J
authors.initials: MJ
authors.lastname: D'Souza
mesh_terms: D016588:Anticarcinogenic Agents / Q000627:therapeutic use*; D000972:Antineoplastic Agents, Phytogenic / Q000008:administration & dosage* / Q000627:therapeutic use*; D002166:Camptothecin / Q000008:administration & dosage* / Q000627:therapeutic use*; D003692:Delayed-Action Preparations / Q000378:metabolism / Q000627:therapeutic use; D016503:Drug Delivery Systems / Q000379:methods*; D004355:Drug Stability; D066298:In Vitro Techniques; D008546:Melanoma, Experimental / Q000188:drug therapy*; D008863:Microspheres; D010316:Particle Size; D011098:Polyglactin 910 / Q000138:chemical synthesis / Q000627:therapeutic use*; D013997:Time Factors; D014407:Tumor Cells, Cultured
chemical_list: D016588:Anticarcinogenic Agents; D000972:Antineoplastic Agents, Phytogenic; D003692:Delayed-Action Preparations; D011098:Polyglactin 910; D002166:Camptothecin