Recent developments in polymer technology have created new opportunities
for ocular drug delivery, which has unique challenges due to specific attributes of the
eye. The unique requirements of ocular drug delivery pose several difficulties for a
formulator to select an appropriate polymer and use it in ODD. Nanotechnology has
opened up new vistas as the nano particle becomes a choice of drug delivery in ODD.
Layers of tissue, blood barriers, choroidal flow, lymphatic drainage, and lacrimation are
some of the factors that limit therapeutic concentrations of drugs from reaching diseased
parts of the eye. Currently, research is being directed towards the identification and
discovery of novel drug delivery systems using newly introduced polymers,
nanoparticles, liposomes, and adhesive gels to circumvent barriers and obtain sustained
levels of therapeutics at target ocular sites. The ocular route of drug delivery is
determined based on disease application and each method presents its own challenge:
topical (uveitis, conjunctivitis), systemic (cytomegalovirus retinitis), intravitreal
(macular degeneration, diabetic reinopathy), subconjunctival (glaucoma), subtenon
(retinal vein occlusion). Formulation factors such as drug loading, drug stability, drug
excipient interaction, carrier biocompatibility and drug carrier biodegradability need to
be considered when designing ocular drug delivery systems. Ocular biocompatibility
and ocular biodegradability are one of the few important characteristics which dictate
the selection of such polymeric materials to be used as ODD carriers. This chapter
covers various aspects of the ocular delivery and discusses the characteristic of the nano
biomaterials to be used as ocular drug delivery carriers.
Keywords: Nanoparticles, Ocular Drug delivery, Liposomes, Mucoadhesive gels,
Age-related macular degeneration, Diabetic retinopathy, Glaucoma, Conjunctivitis,
Polysaccharide, Chitosan.