Design and Evaluation of Hydrophobic Ion-Pairing Complexation of Lysozyme with Sodium Dodecyl Sulfate for Improved Encapsulation of Hydrophilic Peptides/Proteins by Lipid-Polymer Hybrid Nanoparticles

Hydrophobic ion-pairing (HIP) complexation-based approach has been employed to reduce aqueous solubilities of peptide and protein drugs. The solubility of a protein molecule is due to presence of charged amino acids present on the surface. HIP complexation is a technique to complex ionizable functional groups of protein and peptide molecules with oppositely charged functional groups of a complex forming agent. The main objective of this study was to formulate and evaluate HIP complexes of lysozyme with sodium dodecyl sulfate (SDS) as an ion paring agent. Results of % binding effciency shown that the formation of HIP complexes were dependent on pH of lysozyme solution and molar ratio of lysozyme to SDS. Aqueous solubilities of HIP complexes were very low compared to lysozyme alone. The e¬ffect of HIP complexation on enzymatic activity of lysozyme was also studied. Further, lipid-polymer hybrid nanoparticles (LPNs) loaded with lysozyme and lysozyme:SDS HIP complex were prepared by using a solid-in-oil-in-water (s/o/w) emulsion solvent evaporation method and characterised with respect to morphology, size and encapsulation efficiency. We observed significant improvement in encapsulation efficiency for lysozyme:SDS HIP complex-loaded LPNs. This study demonstrates a novel approach of formulating protein-loaded nanoparticles which can also be employed for delivery of proteins. is able to partition largely in to hydrophobic polymer matrix during encapsulation process rather than the external aqueous medium [14,15]. As a result, HIP complexation significantly enhances encapsulation efficiency. This approach offers several advantages including (i) alteration the aqueous solubility of a hydrophilic protein molecule in a reversible manner, (ii) higher solubility of complex in the lipid phase which may result in higher permeation across cell membrane, (iii) enhanced encapsulation of protein molecule in a polymeric matrix, (iv) and (v) providing conformation stability to the protein molecule in the presence of organic solvents. Due to above mentioned reasons, HIP complexation-based technique has started to get acceptance in the preparation of colloidal dosage form such as nanoparticles for proteinbased therapeutics [14,16,17]. In this study, a more liposoluble lysozyme-sodium dodecyl sulfate complex was prepared using the hydrophobic ion pairing method. Sodium dodecyl sulfate (SDS) was used as an ion pairing agent. Then, effect of lysozyme solution pH and molar ratio of lysozyme to SDS on properties of HIP complex were investigated. Furthermore, lipidpolymer hybrid nanoparticles (LPNs) loaded with lysozyme and lysozyme:SDS HIP complex were prepared by using a solid-in-oil-inwater (s/o/w) emulsion solvent evaporation method and characterized with respect to morphology, size and encapsulation efficiency. Citation: Devrim B, Bozkır A (2015) Design and Evaluation of Hydrophobic Ion-Pairing Complexation of Lysozyme with Sodium Dodecyl Sulfate for Improved Encapsulation of Hydrophilic Peptides/Proteins by Lipid-Polymer Hybrid Nanoparticles. J Nanomed Nanotechnol 6: 259. doi: 10.4172/2157-7439.1000259