Preparation, Characterization, Release Kinetics, Antiglycation Activity and Stability Assessment of Catharanthus roseus L. Extracts Encapsulated Alginate Nanoformulations

Abstract

Background: The inclusion of C. roseus extracts into an alginate matrix is identified as a promising strategy for the development of drug candidates, which may help to overcome the limitations commonly associated with plant extracts. Objectives: To prepare and characterize C. roseus incorporated alginate nanoformulations using aqueous, ethanol, 50% ethanol, and 50% acetone extracts, and to assess their in-vitro release kinetics, antiglycation activity, and accelerated stability Methods: The C. roseus extracts encapsulated alginate nanoformulations (CR-ANs) were prepared using ionic gelation technique and characterised. The in-vitro release of polyphenols from CR-ANs was determined at pH 1.2 and pH 6.8 and the data were fitted into zero-order, first- order, Hixon-Crowell and Higuchi models. The antiglycation activity of CR-ANs was assessed. Accelerated stability of C. roseus ethanol extract encapsulated nanoformulation was evaluated based on total polyphenol content and thin layer chromatography fingerprints over a month, at 27 and 5 °C. Results: Ethanol, 50% ethanol, and 50% acetone C. roseus extracts encapsulated alginate nanoparticles obtained more than 80% of encapsulation efficiency. Their loading capacities were determined as 0.9-7%. CR-ANs exhibited a mean particle size of 110-220 nm with a narrow distribution and zeta potentials ranged from -22.7 to -35.0 mV. The release of polyphenols from the alginate matrix was controlled and pH-responsive after the encapsulation. Aqueous and ethanol extracts of C. roseus when encapsulated in alginate nanoformulation fitted best with the first order model, obtaining an R2 value of 0.98 compared to other plant extracts. The antiglycation activity of aqueous, ethanol, and 50% acetone C. roseus extracts encapsulated alginate nanoformulations was significantly (p<0.05) increased at 45.79, 89.16, and 70.93% compared to their crude extracts (IC50: 2.14, 2.86, and 1.00 mg/mL), respectively. Phytoconstituents in ethanol C. roseus extract were preserved upon encapsulation over one month at 27 and 5 °C. Conclusion: The promising findings of ethanol extract of C. roseus encapsulated alginate nanoparticles would facilitate the development of a stable drug lead candidate with controlled release of polyphenols and improved antiglycation activity.