Synthesis, characterization, and in vitro release of oxytetracycline loaded in pH-responsive CaCO3 nanoparticles

Abstract

Alternative drug delivery for the treatment of resistant bacterial infections is necessary to bypass existing antibiotic resistance mechanism and ensure direct delivery of the drug to the targeted site using locally sourced materials to minimize cost in the long term. In this study, cockle shell-derived calcium carbonate aragonite nanoparticles (CS-CaCO3NP) was synthesized, loaded with oxytetracycline (OTC), and characterized using Zeta analysis, Transmission electron microscopy (TEM), FESEM, X-ray Diffraction (XRD), Fourier Transform Infrared (FTIR) and Brunauer-Emmett-Teller analysis. The loaded OTC-CS-CaCO3NP was further characterized after which the in vitro release of OTC was studied. A homogenously spherical CS-CaCO3NP was observed on TEM with a mean diameter of 29.90 nm and-19.9 zeta potential which increased to 62.40 nm and-23.5, respectively, after OTC loading. XRD and FTIR analysis of OTC-CS-CaCO3NP revealed that OTC maintained its functionality and crystallinity. The formulation of OTC:CS-CaCO3NP in ratio 1:4 with drug encapsulating efficiency (71%) was used for in vitro release studies. OTC was sustainably released from OTC-CS-CaCO3NP over a period of 96 hours. Our results suggest that OTC-CSCaCO3NP is a promising nanoparticle antibiotic delivery system with efficient physicochemical and pharmacological properties whose antibiotic properties should be further investigated.