Objective: Anthralin is one of the most effective drugs in psoriasis management. However, its side effects and unfavourable physicochemical properties limit its clinical use. Therefore, the objective of this study was to prepare and evaluate poly (ethylene glycol)-block-poly (ε-caprolactone) (PEG-b-PCL) nanoparticles as a potential delivery system for anthralin.
Methods: PEG-b-PCL nanoparticles were prepared by the co-solvent evaporation method and evaluated using a variety of techniques. The effect of drug/polymer weight feed ratio on the nanoparticle size, drug loading capacity and encapsulation efficiency were studied. Drug release kinetics were studied using the dialysis bag method. Nanoparticle size was measured using dynamic light scattering and confirmed by transmission electron microscopy measurements.
Results: PEG-b-PCL formed spherical nanoparticles having a diameter of 40 to 80 nm based on the polymer and level of drug loading. The size observed by TEM measurements was slightly smaller than that obtained by DLS due nanoparticle dryness during measurement. Drug loading capacity increased with increasing the drug/polymer ratio and a maximum loading of ~25% was obtained. Anthralin encapsulation in the nano particles resulted in ~120-fold increase in its aqueous solubility. Anthralin was released from the nanoparticles over a prolonged period of time where ~ 45% was released in 48 h.
Conclusion: These results confirm the utility of PEG-b-PCL nanoparticles in enhancing the aqueous solubility and sustaining the release of athralin. Therefore, they might be used as a potential delivery system for the treatment of psoriasis.