Synthesis, characterization and in vitro studies of pegylated L-phenylalanine mustard conjugates
Ajazuddin Mohammad Department of Pharmacy
University Institute of Pharmacy
Raipur, INDIA
Abstract:
L-phenylalanine mustard (L-PAM), a drug used for the treatment of breast, ovaries and a certain type of cancer in the bone marrow, was conjugated to linear methoxy poly (ethylene glycol) (M-PEG) of 2,000 and 5,000, Da. An ester linkage between polymer and drug was used in the coupling to yield a polymeric prodrug. Purified esters were characterized by Maldi-Tof and IR spectroscopy methods. The modification allowed overcoming the known L-PAM aqueous solubility problem (0.1µg/ml) leading us to obtain a polymer-drug bioconjugate more suitable for oral and parental administration. It was found that molecular weight of M-PEG is critical for the conjugates stability, aqueous solubility (80 times and 123 times higher aqueous solubility for M-PEG 2000 and M-PEG 500 respectively), and hemolytic activity. The L-PAM caused 100% hemolysis above the concentration 3.5 g/ml in 1 hr. whereas conjugate of M-PEG 2000 and M-PEG 5000 shows 81.3±0.5 % and 48.8±1.5% hemolysis respectively at 32µg/ml after1 hr. Further In vitro anticancer activity of L-PAM and its conjugates was performed with breast cancer MCF-7 cell lines. It shows that LD50 concentration was higher 1.14 and 2 µm for M-PEG 2000 and M-PEG 5000 respectively in comparison to pure L-PAM (0.74 µm). Above studies revealed improved pharmacokinetics properties upon conjugation.
