Hyaluronic acid coated poly-epsilon-caprolactone nanospheres deliver high concentrations of cyclosporine A into the cornea.
The objective of this study was to determine cyclosporine A (Cy A) levels in ocular tissues and fluids after topical administration of poly-epsilon-caprolactone (PCL)/benzalkonium chloride (BKC) nanospheres and hyaluronic acid (HA) coated PCL/BKC nanospheres onto healthy rabbit corneas. Nanospheres were prepared by nanoprecipitation and purified by gradient-rate centrifugation. Cy A (0.1%) in either castor oil solution (group 1), PCL/BKC nanosphere formulation (group 2) or HA coated PCL/BKC nanosphere formulation (group 3) was instilled onto rabbit corneas. Tear samples were adsorbed onto Schirmer tear strips. Cy A concentrations of fluid (blood, aqueous humor, tear) and specimen extracts (cornea, conjunctiva, iris/ciliary body) were determined by high performance liquid chromatography-mass spectrometry (LC-MS). The mean corneal Cy A concentration obtained at 0.5, 1, 2, 4, 8 and 24h following instillation of the formulations ranged between 0.12 and 1.2 ng/mg tissue for group 1, 5.9-15.5 ng/mg tissue for group 2 and 11.4-23.0 ng/mg for group 3 (one-way analysis of variance (ANOVA) and pairwise tests (SNK (Student-Newman-Keuls) and Tukey); p<0.05). Conjunctival Cy A levels of group 2 and 3 were not significantly different at any of the time points tested. However, there was a significant difference between Cy A concentration of castor oil formulation and that of PCL/BKC nanosphere formulation at 1 and 8h (p<0.05). The mean iris/ciliary body concentrations obtained with the three formulations were not significantly different at any time point with the exception of group 2 levels being higher than those of groups 1 and 3 at 1h (p<0.05). The lowest ocular tear Cy A concentrations (16-114 ng/ml) were found following the instillation of HA coated PCL/BKC nanoparticles (group 3) during the time period tested. Cy A loaded PCL/BKC and HA coated PCL/BKC nanospheres are able to achieve high levels of Cy A in the cornea that is 10-15-fold higher than that is achieved with Cy A solution in castor oil. Nanosphere formulation and HA may play an important role in delivering high levels of cyclosporine A into the cornea.
Yenice
Irem
I
Department of Pharmaceutical Technology, Faculty of Pharmacy, Hacettepe University, 06100 Ankara, Turkey. iyenice@hacettepe.edu.tr
Mocan
Mehmet C
MC
Palaska
Erhan
E
Bochot
Amélie
A
Bilensoy
Erem
E
Vural
Imran
I
Irkeç
Murat
M
Hincal
A Atilla
AA
D000818:Animals; D001682:Biological Availability; D002208:Caproates; D003315:Cornea / Q000378:metabolism*; D016572:Cyclosporine / Q000008:administration & dosage* / Q000493:pharmacokinetics; D004337:Drug Carriers / Q000737:chemistry*; D016503:Drug Delivery Systems; D006820:Hyaluronic Acid; D007166:Immunosuppressive Agents / Q000008:administration & dosage* / Q000493:pharmacokinetics; D007783:Lactones; D008297:Male; D054118:Nanospheres; D009883:Ophthalmic Solutions; D011817:Rabbits; D013666:Tears / Q000378:metabolism
D002208:Caproates; D004337:Drug Carriers; D007166:Immunosuppressive Agents; D007783:Lactones; D009883:Ophthalmic Solutions; C121056:caprolactone; D016572:Cyclosporine; D006820:Hyaluronic Acid