Preparation and <i>in vitro</i> evaluation of injectable formulations of levothyroxine sodium using <i>in situ</i> forming hydrogel temperature-responsive systems based on PLA-PEG-PLA and PLGA-PEG-PLGA triblock copolymers.
Jebraeil Movaffagh, Farzin Hadizadeh, Elham Khodaverdi, Bahnaz Khalili, Seyedeh Nesa Rezaeian Shiadeh, Hossein Kamali, Fatemeh Oroojalian
Abstract
Objectives: Recently, great attention has been paid to developing new drug delivery systems to manage the rate, time, and site of drug release. We aimed to design a novel drug delivery system to support targeted and gradual delivery of levothyroxine sodium. Materials and Methods: drug release into the PBS was measured at different concentrations of the triblocks for one month. Results: C while levothyroxine sodium remained stable. Initial burst release of the drug in both copolymers is inversely correlated with the concentration of the polymer. Evaluation of drug release for 35 days showed that PLA-PEG-PLA had a slower drug release rate than PLGA-PEG-PLGA. Conclusion: Considering the low initial burst release, as well as continuous and long-term release kinetics of PLA-PEG-PLA and PLGA-PEG-PLGA copolymers, they can be used to gradually deliver levothyroxine sodium, obviating the need for frequent administrations and concerns over drug-food interactions.