Dorzolamide Loaded Niosomal Vesicles: Comparison of Passive and Remote Loading Methods

Area of Science:

• Pharmaceutical Sciences
• Ophthalmology
• Nanotechnology

Background:

• Glaucoma is a progressive eye disease requiring effective intraocular pressure (IOP)-lowering agents.
• Nanoparticulate delivery systems offer potential for improved drug loading and sustained release of glaucoma medications.
• Niosomes show promise for enhancing corneal drug penetration and bioavailability, but hydrophilic drug entrapment remains a challenge.

Purpose of the Study:

• To optimize the formulation of dorzolamide niosomes for enhanced encapsulation efficiency.
• To investigate the impact of various formulation parameters on dorzolamide encapsulation within niosomes.
• To compare passive and remote loading methods for dorzolamide entrapment in niosomal formulations.

Main Methods:

• Dorzolamide niosomes were prepared using passive and remote loading techniques.
• The influence of lipid-to-drug ratio, cholesterol percentage, drug concentration, freeze/thaw cycles, TPGS content, and buffer conditions on encapsulation efficiency (EE) was evaluated.
• Scanning electron microscopy (SEM) was used to characterize the morphology of the prepared niosomes.

Main Results:

• Higher cholesterol percentage and increased total lipid concentration significantly enhanced dorzolamide encapsulation.
• The remote loading method (phosphate gradient) demonstrated superior drug entrapment efficiency compared to passive loading.
• TPGS incorporation decreased EE but retarded drug release; SEM confirmed spherical, homogeneous niosomes.

Conclusions:

• The phosphate gradient remote loading method combined with 50% cholesterol in Span 60 niosomes yields the highest encapsulation efficiency for dorzolamide.
• Optimized niosomal formulations hold promise for improved sustained delivery of IOP-lowering agents in glaucoma management.
• Further research can leverage these findings for developing advanced ophthalmic drug delivery systems.