Niosomes Encapsulated Pilocarpine Hydrochloride for Ocular Controlled Delivery

Author(s): Neelam Jain*, Anurag Verma and Neeraj Jain

Abstract: The main purpose of the current study was to investigate the feasibility of niosomes as carriers for the ocular controlled delivery of a cholinergic drug; pilocarpine HCl. In the present study, pilocarpine HCl loaded niosomes were prepared using various non-ionic surfactants (span-20, span-60 and span-80) in the presence of cholesterol in different molar ratios by ether injection method. The ability of these vesicles to entrap the studied drug was determined by evaluating the entrapment efficiency after centrifugation and separation of the formed vesicles. Photomicroscopy and transmission electron microscopy as well as vesicle size analysis were used to study the formation, morphology and size of the drug loaded niosomes. The surface properties of prepared niosomes were determined by zeta potential. Fourier transform infrared spectroscopy and differential scanning colorimetry was done to investigate the drug-excipients compatibility and the chemical stability of drug after penetration into the niosomes. TEM analysis confirmed that niosomal formulations were spherical in shape and has a definite internal aqueous space. Results showed a substantial change in the release rate and an alteration in the drug entrapment efficiency from niosomal formulations upon varying type of surfactant and cholesterol content. In vitro drug release results confirmed that niosomal formulations have exhibited a high retention of pilocarpine HCl inside the vesicles such that their in vitro release was slower and more controlled. A formulation with 1:1 molar ratio of span-60 and cholesterol gave the most advantageous entrapment (93.26±1.75%) and release results after 8 hours (Q8h=66.98±1.87%) as compared to other compositions. These results confirm that niosomes containing formulations may be considered as promising ophthalmic carriers for the topical application of pilocarpine HCl.

PAGES: 813-823  |  50 VIEWS  179 DOWNLOADS