Diclofenac sodium ion exchange resin complex loaded melt cast films for sustained release ocular delivery.
OBJECTIVE
The goal of the present study is to develop polymeric matrix films loaded with a combination of free diclofenac sodium (DFSfree) and DFS:Ion exchange resin complexes (DFS:IR) for immediate and sustained release profiles, respectively.


METHODS
Effect of ratio of DFS and IR on the DFS:IR complexation efficiency was studied using batch processing. DFS:IR complex, DFSfree, or a combination of DFSfree+DFS:IR loaded matrix films were prepared by melt-cast technology. DFS content was 20% w/w in these matrix films. In vitro transcorneal permeability from the film formulations were compared against DFS solution, using a side-by-side diffusion apparatus, over a 6 h period. Ocular disposition of DFS from the solution, films and corresponding suspensions were evaluated in conscious New Zealand albino rabbits, 4 h and 8 h post-topical administration. All in vivo studies were carried out as per the University of Mississippi IACUC approved protocol.


RESULTS
Complexation efficiency of DFS:IR was found to be 99% with a 1:1 ratio of DFS:IR. DFS release from DFS:IR suspension and the film were best-fit to a Higuchi model. In vitro transcorneal flux with the DFSfree+DFS:IR(1:1)(1 + 1) was twice that of only DFS:IR(1:1)film. In vivo, DFS solution and DFS:IR(1:1)suspension formulations were not able to maintain therapeutic DFS levels in the aqueous humor (AH). Both DFSfreeand DFSfree+DFS:IR(1:1)(3 + 1) loaded matrix films were able to achieve and maintain high DFS concentrations in the AH, but elimination of DFS from the ocular tissues was much faster with the DFSfreeformulation.


CONCLUSIONS
DFSfree+DFS:IR combination loaded matrix films were able to deliver and maintain therapeutic DFS concentrations in the anterior ocular chamber for up to 8 h. Thus, free drug/IR complex loaded matrix films could be a potential topical ocular delivery platform for achieving immediate and sustained release characteristics.
a Department of Pharmaceutics and Drug Delivery, School of Pharmacy, The University of Mississippi, University , MS , USA.
Goutham R
GR
Adelli
a Department of Pharmaceutics and Drug Delivery, School of Pharmacy, The University of Mississippi, University , MS , USA.
Sai Prachetan
SP
Balguri
a Department of Pharmaceutics and Drug Delivery, School of Pharmacy, The University of Mississippi, University , MS , USA.
Prakash
P
Bhagav
b National Center for Natural Products Research, School of Pharmacy, The University of Mississippi, University , MS , USA , and.
Vijayasankar
V
Raman
a Department of Pharmaceutics and Drug Delivery, School of Pharmacy, The University of Mississippi, University , MS , USA.|c Research Institute of Pharmaceutical Sciences, The University of Mississippi, University , MS , USA.
Soumyajit
S
Majumdar
D060433:Administration, Ophthalmic; D000287:Administration, Topical; D000818:Animals; D002626:Chemistry, Pharmaceutical; D003692:Delayed-Action Preparations / Q000008:administration & dosage / Q000737:chemistry / Q000378:metabolism*; D004008:Diclofenac / Q000008:administration & dosage / Q000737:chemistry / Q000378:metabolism*; D016503:Drug Delivery Systems / Q000379:methods*; D005123:Eye / Q000187:drug effects / Q000378:metabolism*; D007475:Ion Exchange Resins / Q000008:administration & dosage / Q000737:chemistry / Q000378:metabolism*; D008297:Male; D009883:Ophthalmic Solutions / Q000008:administration & dosage / Q000737:chemistry / Q000378:metabolism*; D009924:Organ Culture Techniques; D011817:Rabbits
D003692:Delayed-Action Preparations; D007475:Ion Exchange Resins; D009883:Ophthalmic Solutions; D004008:Diclofenac
Ion exchange resins; diclofenac sodium and polymeric matrix films; immediate release formulations; ocular drug delivery