Purchase this article with an account.
Thomas Rowe, Kenneth Reed, Tuhin Bhowmik; Optimization of In-vitro DiffER model to study/compare the effect of Formulations on Cross-Scleral transport of poorly aqueous soluble drug. Invest. Ophthalmol. Vis. Sci. 2013;54(15):5071.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Ophthalmic drugs intended for the treatment of back of the eye disorders often suffers the limitation of cross-scleral penetration to achieve therapeutic efficacy. The purpose of this study was to optimize the Diffusion-erosion in-vitro model (DiffER) to understand the behavior of the drug diffusion/ transport from the formulation into the sclera and out to the receptor media. This method will help us to pre-screen various formulations at an early Formulation & Development Phase to indicate the possibility of extending the formulation to be tested on animal models.
Frozen mature rabbit scleras were thawed in diffusion media and placed on specially adapted spherical diffusion Franz Cells and dosed with 0.3 mg (about 2 drops) of active in three different formulations (emulsion, aqueous suspension, and paraffin suspension). For the dynamic experiments the pre corneal layer was initially flushed with PBS at an increased flow rate immediately post-dosage to simulate reflex tear flow then reduced to a basal flow rate for the remaining duration of the experiment. To evaluate drug retention and extent of absorption characteristics of each formulation, eroded solution from the pre-corneal layer was collected at intervals for analysis. Receiver chamber solution was also sampled at selected intervals. Analysis of samples were performed via HPLC
The results from the DiffER experiment were contrasting and varied from formulation to formulation. The order of drug transport in the formulation was quantified and permeability co-efficients were calculated.
The DiffER may be efficiently utilized as an in-vitro tool to discern the rate of drug transport through optic tissues between different drug formulations.
This PDF is available to Subscribers Only