Preparation and evaluation of liposomal formulations of tropicamide for ocular delivery

• Published in: International journal of pharmaceutics 1999-11, Vol.190 (1), p.63-71
• Main Authors: Nagarsenker, M.S, Londhe, Vaishali Y, Nadkarni, G.D
• Format: Article
• Language: English
• Subjects: Animals; Area Under Curve; Biological and medical sciences; Biological Availability; Chemistry, Pharmaceutical; Drug Compounding; Drug Delivery Systems; Evaluation Studies as Topic; Eye; Eye - metabolism; General pharmacology; Liposomes; Liposomes - administration & dosage; Liposomes - chemistry; Male; Medical sciences; Metabolic Clearance Rate; Particle Size; Pharmaceutical technology. Pharmaceutical industry; Pharmacology. Drug treatments; Pupil - drug effects; Pupil dilatory effect; Rabbits; Temperature; Time Factors; Tropicamide; Tropicamide - chemistry; Tropicamide - pharmacokinetics; γ-Scintigraphy
• ISSN: 0378-5173; 1873-3476
• DOI: 10.1016/S0378-5173(99)00265-3

Tropicamide, a mydriatic, cycloplegic drug was entrapped in liposomes. Liposomes were investigated by laser counting studies, transmission electron microscopy and differential scanning calorimetry for characterization. The precorneal clearance of liposomes was compared with solution by γ-scintigraphy in the rabbit. The neutral liposomes failed to demonstrate significant enhancement in precorneal retention in comparison with aqueous solution. The potential of liposomes as an ophthalmic drug delivery system was investigated by comparing pupil dilatory effect of tropicamide by topical instillation, in the rabbit eye, of the solution and various drug-loaded liposomal forms, i.e. neutral liposomes, positively charged liposomes and neutral liposomes dispersed in 0.25% (w/v) polycarbophil gel. The positively charged liposomal formulation and liposomes dispersed in polycarbophil gel were found to be more effective than neutral liposomal dispersion when data were statistically treated at the 5% level of significance.