Structure–permeability Relationships for Transcorneal Penetration

Topical Nanoemulsion of an Runt-related Transcription Factor 1 Inhibitor for the Treatment of Pathologic Ocular Angiogenesis

Purpose

To test the efficacy of runt-related transcription factor 1 (RUNX1) inhibition with topical nanoemulsion containing Ro5-3335 (eNano-Ro5) in experimental ocular neovascularization.

Design

Preclinical experimental study.

Participants

In vitro primary culture human retinal endothelial cell (HREC) culture. C57BL/6J 6- to 10-week-old male and female mice.

Methods

We evaluated the effect of eNano-Ro5 in cell proliferation, cell toxicity, and migration of HRECs. We used an alkali burn model of corneal neovascularization and a laser-induced model of choroidal neovascularization to test in vivo efficacy of eNano-Ro5 in pathologic angiogenesis in mice. We used mass spectrometry to measure penetration of Ro5-3335 released from the nanoemulsion in ocular tissues.

Main Outcome Measures

Neovascular area.

Results

RUNX1 inhibition reduced cell proliferation and migration in vitro. Mass spectrometry analysis revealed detectable levels of the active RUNX1 small-molecule inhibitor Ro5-3335 in the anterior and posterior segment of the mice eyes. Topical treatment with eNano-Ro5 significantly reduced corneal neovascularization and improved corneal wound healing after alkali burn. Choroidal neovascularization lesion size and leakage were significantly reduced after treatment with topical eNano-Ro5.

Conclusions

Topical treatment with eNano-Ro5 is an effective and viable platform to deliver a small-molecule RUNX1 inhibitor. This route of administration offers advantages that could improve the management and outcomes of these sight-threatening conditions. Topical noninvasive delivery of RUNX1 inhibitor could be beneficial for many patients with pathologic ocular neovascularization.

Recent trends in the transdermal delivery of therapeutic agents used for the management of neurodegenerative diseases

With the increasing proportion of the global geriatric population, it becomes obvious that neurodegenerative diseases will become more widespread. From an epidemiological standpoint, it is necessary to develop new therapeutic agents for the management of Alzheimer's disease, Parkinson's disease, multiple sclerosis and other neurodegenerative disorders. An important approach in this regard involves the use of the transdermal route. With transdermal drug delivery systems (TDDS), it is possible to modulate the pharmacokinetic profiles of these medications and improve patient compliance. Transdermal drug delivery has also been shown to be useful for drugs with short half-life and low or unpredictable bioavailability. In this review, several transdermal drug delivery enhancement technologies are being discussed in relation to the delivery of medications used for the management of neurodegenerative disorders.

Development of novel in silico model to predict corneal permeability for congeneric drugs: a QSPR approach

This study was undertaken to determine in vivo permeability coefficients for fluoroquinolones and to assess its correlation with the permeability derived using reported models in the literature. Further, the aim was to develop novel QSPR model to predict corneal permeability for fluoroquinolones and test its suitability on other training sets. The in vivo permeability coefficient was determined using cassette dosing (N-in-One) approach for nine fluoroquinolones (norfloxacin, ciprofloxacin, lomefloxacin, ofloxacin, levofloxacin, sparfloxacin, pefloxacin, gatifloxacin, and moxifloxacin) in rabbits. The correlation between corneal permeability derived using in vivo studies with that derived from reported models was determined. Novel QSPR-based model was developed using in vivo corneal permeability along with other molecular descriptors. The suitability of developed model was tested on β-blockers (n = 15). The model showed better prediction of corneal permeability for fluoroquinolones (r(2) > 0.9) as well as β-blockers (r(2) > 0.6). The newly developed QSPR model based upon in vivo generated data was found suitable to predict corneal permeability for fluoroquinolones as well as other sets of compounds.

Simple stochastic fingerprints towards mathematical modeling in biology and medicine. 3. ocular irritability classification model

MARCH-INSIDE methodology and a statistical classification method--linear discriminant analysis (LDA)--is proposed as an alternative method to the Draize eye irritation test. This methodology has been successfully applied to a set of 46 neutral organic chemicals, which have been defined as ocular irritant or nonirritant. The model allow to categorize correctly 37 out of 46 compounds, showing an accuracy of 80.46%. Specifically, this model demonstrates the existence of a good categorization average of 91.67 and 76.47% for irritant and nonirritant compounds, respectively. Validation of the model was carried out using two cross-validation tools: Leave-one-out (LOO) and leave-group-out (LGO), showing a global predictability of the model of 71.7 and 70%, respectively. The average of coincidence of the predictions between leave-one-out/leave-group-out studies and train set were 91.3% (42 out of 46 cases)/89.1% (41 out of 46 cases) proving the robustness of the model obtained. Ocular irritancy distribution diagram is carried out in order to determine the intervals of the property where the probability of finding an irritant compound is maximal relating to the choice of find a false nonirritant one. It seems that, until today, the present model may be the first predictive linear discriminant equation able to discriminate between eye irritant and nonirritant chemicals.

A study of the relationship between cornea permeability and eye irritation using membrane-interaction QSAR analysis

A methodology termed membrane-interaction QSAR (MI-QSAR) analysis has been used to develop QSAR models to predict drug permeability coefficients across cornea and its component layers (epithelium, stroma, and endothelium). From a training set of 25 structurally diverse drugs, significant QSAR models are constructed and compared for the permeability of the cornea, epithelium, and stroma plus endothelium. Cornea permeability is found to depend on the measured distribution coefficient of the drug, the cohesive energy of the drug, the total potential energy of the drug-membrane "complex," and three other energy refinement descriptor terms. The endothelium may be a more important barrier in cornea permeation than the stroma. Moreover, an investigation of the correlation between cornea permeation and eye irritation is presented as an example of a cross study on different ADMET properties using MI-QSAR analysis. Thirteen structurally diverse drugs, whose molar-adjusted eye irritation scores (MES) have been measured using the Draize rabbit-eye test, were chosen as an eye irritation comparison set. A poor correlation (R(2) = 0.0232) between the MES measures and the predicted cornea permeability coefficients for the drugs in the eye irritation set suggests there is no significant relationship between eye irritation potency and the cornea permeability.

Predicted permeability of the cornea to topical drugs

PURPOSE

To develop a theoretical model to predict the passive, steady-state permeability of cornea and its component layers (epithelium, stroma, and endothelium) as a function of drug size and distribution coefficient (phi). The parameters of the model should represent physical properties that can be independently estimated and have physically interpretable meaning.

METHODS

A model was developed to predict corneal permeability using 1) a newly developed composite porous-medium approach to model transport through the transcellular and paracellular pathways across the epithelium and endothelium and 2) previous work on modeling corneal stroma using a fiber-matrix approach.

RESULTS

The model, which predicts corneal permeability for molecules having a broad range of size and lipophilicity, was validated by comparison with over 150 different experimental data points and showed agreement with a mean absolute fractional error of 2.43, which is within the confidence interval of the data. In addition to overall corneal permeability, the model permitted independent analysis of transcellular and paracellular pathways in epithelium, stroma and endothelium. This yielded strategies to enhance corneal permeability by targeting epithelial paracellular pathways for hydrophilic compounds (phi < 0.1 - 1), epithelial transcellular pathways for intermediate compounds, and stromal pathways for hydrophobic compounds (phi > 10 - 100). The effects of changing corneal physical properties (e.g., to mimic disease states or animals models) were also examined.

CONCLUSIONS

A model based on physicochemical properties of the cornea and drug molecules can be broadly applied to predict corneal permeability and suggest strategies to enhance that permeability.