Formulation design and optimization of cationic-charged liposomes of brimonidine tartrate for effective ocular drug delivery by design of experiment (DoE) approach

• Published in: Drug development and industrial pharmacy p. 1
• Main Authors: Soni, Prakash K, Saini, T R
• Format: Journal Article
• Language: English
• Published: England 19.05.2022
• Subjects: Brimonidine tartrate; Box–Behnken design (BBD) optimization; trans-corneal drug permeation; drug release kinetics of liposome; formulation optimization of liposome; design of experiment (DoE); ocular drug delivery; cationic charged liposome
• ISSN: 1520-5762

The present study was aimed to design and optimize brimonidine tartrate (BRT) loaded cationic-charged liposome formulation with enhanced trans-corneal drug permeation, prolonged corneal residence, and sustained drug release for effective ocular delivery. Design of experiment (DoE) based formulation optimization was done by three-factor, three-level Box-Behnken design selecting lipid, cholesterol, and drug content as independent variables and particle size (PS), polydispersity index (PDI), zeta potential (ZP), entrapment efficiency (EE%), and cumulative % drug release (CDR) as response variables. The optimized formulation consisting of 79.2 mM lipid, 36.2 mM cholesterol, and 15.8 mg/mL drug was prepared by thin film hydration-sonication method using EPCS:DOTAP (1:1) as lipid component and characterized for all desired critical quality attributes (CQAs), drug release kinetics, TEM, DSC, XRD analysis, trans-corneal drug permeation, and physical stability studies. The optimized liposome formulation exhibited experimentally observed responses close to predicted values having 150.4 nm (PS), 0.203 (PDI), 30.62 mV (ZP), and 55.17% (EE). The observed CDR (%) was 36.15% at 1 h and 91.13% at 12 h exhibiting sustained drug release profile and followed Higuchi drug release kinetics. The TEM, DSC, and XRD studies revealed spherical, nanosized, small unilamellar vesicles effectively entrapping BRT in liposomes. The permeation study across goat cornea recorded apparent permeability ( ) 1.011 ± 0.07 cm.min and steady-state flux ( ) 17.63 ± 1.22 µg.cm .min showing >2-fold enhanced drug permeation as compared to BRT solution. The developed liposomal formulation possessed all recommended CQAs in optimal range with enhanced trans-corneal drug permeation and remained physically stable in 3 months stability study.