Development of Timolol Maleate Loaded Chitosan Nanoparticles For Improved Ocular Delivery

The poor retention and penetration are the major issues in the bioavailability of drugs through ocular route. Recently, the natural polymers have been exploited for the development of nanoparticles to improve the ocular performance of various drugs. In the present investigation, nanoparticles of timolol maleate (TM) were developed by using chitosan polymer to improve its release through ocular delivery.

Ionic gelation method was used for the development of timolol loaded chitosan nanoparticles by using a cross linking agent, sodium tripolyphosphate (NaTPP). The Box- Behnken design was used for the optimization of various parameters for the development of nanoparticles.

The objective behind the study was to study the effect of three critical parameters; concentration of chitosan (X1), the concentration of NaTPP (X2), and the volume of NaTPP (X3) on the drug release from the prepared nanoparticles.

The results obtained showed that high level of the chitosan concentration and low level of the NaTPP concentration and the mid levels of the NaTPP volume resulted in high levels of encapsulation efficiency. The loading capacity was found maximum at a low level of chitosan and mid level of volume of the NaTPP with a low level of NaTPP concentration. The optimized batch (NP-2) showed that the entrapment efficiency was 75.34±0.17%, the particle size of 190.9 nm and in vitro cumulative percentage of drug release was 49.11±0.49% in 12 h.

The study concluded that chitosan nanoparticles loaded with timolol maleate resulted in improved drug release for ocular treatment.