Polyionic hybrid nano-engineered systems comprising alginate and chitosan for antihypertensive therapeutics

• Carbohydrate macromolecules based hybrid nano-carrier system (NCS) development.
• Polyionic NCS: to improve oral administration of hydrophobic antihypertensive drugs.
• Sodium alginate and chitosan cross-linking: mucoadhesive system for controlled release.
• FTIR spectroscopy revealed drug-polymer and polymer-polymer interaction.
• Stable nano-systems with positive zeta potential and high loading capacity (42–96%).

Hydrophobic nature of virtually all antihypertensive (AHT) drugs is the major hindrance towards their oral administration. Current study focuses on the development of polyionic hybrid nano drug delivery systems comprising sodium alginate and chitosan, loaded with distinct AHT drugs (captopril, amlodipine and valsartan). Encapsulation efficiency of hybrid NCS increased in the order of amlodipine > valsartan > captopril with average value of 42 ± 0.9%, 91 ± 1.5% and 96 ± 1.9%, respectively. Scanning electron microscopy revealed hybrid NCS with smooth topography and round appearance in case of captopril. FTIR analysis confirmed the cross-linking between amino and carboxylate group of chitosan and alginate to form polyionic structures at nano-scale. Zeta-sizer experiments revealed that particle size distribution had increased from 197 ± 12 nm to 341 ± 15 nm for void and captopril loaded NCS. However, highly positive zeta potential of +32 ± 1.6 mV was not decreased significantly. In vitro sustained release assays reflected excellent retention of AHT drug in hybrid nanoparticles at 4 °C and 37 °C in physiological buffer, as less than 8% of the total drug was released in first 24 h. Thus, carbohydrate-based hybrid NCS offering high loading capacity, stability and sustained release of hydrophobic drugs can be excellent alternative to current AHT therapeutics.