Novel nanoparticulate gel formulations of steroids for the treatment of macular edema.
OBJECTIVE
This article describes the development and characterization of PLGA nanoparticles of dexamethasone (DEX), hydrocortisone acetate (HA), and prednisolone acetate (PA) suspended in thermosensitive gels indicated for the treatment of macular edema (ME).


METHODS
Nanoparticles were prepared by oil-in-water (O/W) emulsion and dialysis methods using PLGA 50:50 and PLGA 65:35. These particles were characterized for entrapment efficiency, size distribution, surface morphology, crystallinity, and in vitro release. Further, ex vivo permeation studies of DEX in suspension and nanoparticulate formulations were carried out across the rabbit sclera.


RESULTS
Entrapment efficiencies of DEX, HA, and PA were found to be lower with the dialysis method. O/W emulsion/solvent evaporation technique resulted in higher entrapment efficiencies, that is, 77.3%, 91.3%, 92.3% for DEX, HA, and PA, respectively. Release from nanoparticles suspended in thermosensitive gels followed zero-order kinetics with no apparent burst effect. Ex vivo permeability studies further confirmed sustained release of DEX from nanoparticles suspended in thermosensitive gels.


CONCLUSIONS
These novel nanoparticulate systems containing particles suspended in thermosensitive gels may provide sustained retina/choroid delivery of steroids following episcleral administration.
Division of Pharmaceutical Sciences, School of Pharmacy, University of Missouri-Kansas City, Kansas City, Missouri 64108-2718, USA.
Sai H S
SH
Boddu
Jwala
J
Jwala
Ravi
R
Vaishya
Ravinder
R
Earla
Pradeep K
PK
Karla
Dhananjay
D
Pal
Ashim K
AK
Mitra
D000818:Animals; D003692:Delayed-Action Preparations; D003907:Dexamethasone / Q000008:administration & dosage; D003956:Dialysis; D004655:Emulsions; D005782:Gels; D005938:Glucocorticoids / Q000008:administration & dosage; D006854:Hydrocortisone / Q000008:administration & dosage / Q000031:analogs & derivatives; D007700:Kinetics; D019344:Lactic Acid; D008269:Macular Edema / Q000188:drug therapy*; D053758:Nanoparticles; D010539:Permeability; D011100:Polyglycolic Acid; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011239:Prednisolone / Q000008:administration & dosage / Q000031:analogs & derivatives; D011817:Rabbits; D012590:Sclera / Q000378:metabolism; D013256:Steroids / Q000008:administration & dosage* / Q000493:pharmacokinetics; D013696:Temperature
D003692:Delayed-Action Preparations; D004655:Emulsions; D005782:Gels; D005938:Glucocorticoids; D013256:Steroids; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; C021650:hydrocortisone acetate; D003907:Dexamethasone; C009935:prednisolone acetate; D011239:Prednisolone; D006854:Hydrocortisone