Advancement in Ocular Drug Delivery System to Overcome Ocular Barrier

The Ocular drug delivery system (ODDS) is the prominently challenging system faced by pharmaceutical researchers. Ophthalmic preparations are available in buffered, sterile and isotonic solutions. For the ocular delivery of drugs, various types of dosage forms are prepared and dispensed. As the drops are easier for the administration likewise more prescribed dosage form is the eye drop solution. For obtaining prolonged therapeutic effect ointment, suspensions and gelled systems are also used. The presence of various barriers as anatomical, physiological and physiochemical barriers makes difficulties in delivery of drugs in at the intended sites. Scientists invented alternate delivery routes to direct access at intended target sites. Second invention involves development of novel drug delivery systems providing better permeability, treatability and controlled release at target site. The liposomal delivery is beneficial because they have the ability of envelopment and both hydrophobic and hydrophilic drugs are suitable for delivery to both the anterior and posterior segment of the eye. Therefore, the uses of this alternative approach become quite a necessary. This formulation of novel devices will definitely help to the overcome ocular barriers and side effects with conventional topical drops. Current reviews on the conventional formulations of ocular delivery and their advancements followed by current nanotechnology based on the formulation developments. The recent incident with other ocular drug delivery planning consists of in situ gels, implants, contact lens and nano wafers are discussed. Drug delivery at ophthalmic route has been proven significant advancement for the future perspectives.

Development and Characterization of Acetazolamide Nanoemulsion for Effective Ocular Delivery

Nanoemulsion has the potential of releasing the drug continuously, and they may easily permeate via the intense layers of the eye structure due to nano-size droplets, which makes nanoemulsion an effective drug delivery system for ocular delivery. The objective of our work was to prepare a nanoemulsion of acetazolamide for glaucoma treatment with enhanced efficacy as well as for continuous effect. Based on different compositions of oil (Olive Oil), surfactants (Tween-20), and co-surfactants (Transcutol P), forty-five test mixtures were made, water titration technique was employed for preparing the pseudo-ternary-phase diagrams. On the basis of these phase diagrams, twenty-five acetazolamide loaded nanoemulsion were formulated and examined for their nanosized droplets, PDI, zeta potential, viscosity, pH, transmittance and in-vitro drug release. The formulated nanoemulsion showed all the properties within the desired range i.e., droplet size (15.6 to 21.18), zeta potential (-15.5 to- 24.71), PDI (0.140 to 0.361), viscosity (3.234 ± 0.063to 5.174 ± 0.023cps), pH (6.922 ± 0.026to 7.033 ± 0.012), RI (1.379 ± 0.007 to 1.404 ± 0.006) and % transmittance was found (94.96± 0.6% to 96.68± 0.6%) and also the release rate of acetazolamide from nanoemulsion was found very good i.e., 81.59± 1.04% to 92.46± 0.33% after 24 hrs. The top four formulations having good drug release were selected for further evaluation of droplet sizes and which also fall in the nano range (15.68 to 21.18 nm). The study showed that it is possible to develop nanoemulsion of phenytoin drug, and the in-vitro drug release study showed that the prepared nanoemulsion had good bioavailability, sustained release and ability to target eye as an effective ocular delivery system.