Preparation and in vitro characterization of poly(sebacic acid-co-ricinoleic acid)-based tamoxifen citrate-loaded microparticles for breast cancer

This study was aimed to develop an injectable polymeric drug delivery system for tamoxifen citrate (TC) using poly(sebacic acid-co-ricinoleic acid) [poly(SA-RA) 70: 30 w/w] as a drug carrier for the treatment of estrogen receptor positive breast cancer. Injectable biodegradable microparticles of TC were produced by solvent displacement technique of microencapsulation and were characterized by surface morphology (scanning electron microscopy), particle size, size distribution, physical and chemical interaction (Fourier transform infrared), nature and physical state of drug [DSC and X-ray diffraction (XRD)], and in vitro release studies. TC loading over different concentrations was analyzed by high performance liquid chromatography (HPLC) technique. Polyanhydride microparticles obtained after lyophilization were nearly spherical in shape with smooth surface and size less than 2.5 μm. TC was dispersed in the form of amorphous state, and TC remains intact and stable during the process of microencapsulation. In vitro drug release studies demonstrated prolonged controlled release of TC with zero-order kinetics. Stability studies revealed that the production process of microparticles itself did not affect the chemical stability of the drug and polymer forming the particle matrix. Significant difference in drug release capacity was observed in microparticles with different drug loadings, and the drug release was more sustained in microparticles prepared with high TC.