Tailored PLGA nanoparticles emulsified with TPGS for controlled ocular drug delivery
Musarrat Husain Warsi*, Mohammad Yusuf, Majed Al-Robaian, Mohammad Akhlaqur Rahman, Gaurav K Jain
Taif University, Taif, KSA; Jamia Hamdard, New Delhi, India
Abstract: Ocular drug delivery is one of the most challenging endeavour faced by the formulation scientist. As being the vital organ of vision, eye is equipped with urbane anatomic structures and shielding mechanisms to preserve the highly regulated and confined milieu for its function. Due to these precise barricades the bioavailability of ocular drugs after topical instillation is quite poor. For effective handling of ocular ailments need to overcome these barriers. For the same, an optimum ocular delivery system should be design, that can fulfill the various attributes like to meet patient compliance, low dose frequency, well tolerated without causing blurring or irritation, and finally should be effective with increased permeability & ocular bioavailability.
Formulation of polymeric nanoparticles as ocular drug delivery systems can meet the above prerequisite in a large extent. In present research, polymeric nanoparticles were produced by the emulsification technique. There are various fabrication parameters, which affect the nature of the nanoparticles. Among them, the role of an emulsifier is an important one. Emulsiﬁer stabilises the dispersed-phase droplets formed during emulsiﬁcation, inhibits coalescence of droplets and determines the particle size, size distribution, the morphological properties as well as the release properties of the nanoparticles formed. Traditional and most popular emulsiﬁer is poly(vinyl alcohol) (PVA), the use of which is plagued by various drawbacks such as difficulty in complete removal from formulated nanoparticles following the fabrication process. Hence, the present research is focus on exploring the emulsiﬁer, D-α-tocopheryl polyethylene glycol 1000 succinate (vitamin E TPGS, or TPGS) as an alternative to the traditional PVA for fabrication of PLGA nanoparticles as an ocular drug delivery system. TPGS presents several desirable attributes as a PVA substitute. Along with its nature as surfactant & stabilizer, it has also been reported to inhibit efflux transporters localized in the eye. These inherent qualities of TPGS in conjunction were hypothesized to facilitate the production of stable PLGA nanoparticles with the ability to enhance ocular bioavailability of entrapped drug betaxolol for effective management of glaucoma.