Mitoxantrone-loaded BSA nanospheres and chitosan nanospheres for local injection against breast cancer and its lymph node metastases: I: Formulation and in vitro characterization

Positively charged mitoxantrone (MTO) was absorbed by negatively charged blank bovine serum albumin (BSA) and chitosan (CS) nanospheres to form MTO–BSA–NS and MTO–CS–NS, respectively. In addition to other conditions, values of pH of every step were optimized. On optimized conditions, MTO–BSA–NS of a mean size of 77 nm with an encapsulation yield (EY) of (98.86 ± 1.43)% [drug loading rate (DL) (19.82 ± 0.29)%] and MTO–CS–NS of a mean size of 75 nm with an EY of (97.57 ± 1.00)% [DL (9.78 ± 0.10)%] were obtained. After lyophilization and sterilization by 60Co, the mean size increased about 10% but no significant change was observed in EY and DL. Tests for in vitro release in physiological saline or physiological saline containing 0.5% (w/v) ascorbic acid by a dialysis bag showed sustained release and little burst effect.