Comparison of Usage and Effectiveness between Methoxy Polyethylene Glycol Epoetin Beta and Darbepoetin Alfa with Hemodialysis Patients

Methoxy polyethylene glycol epoetin beta which has a long half-life is developed to provide stable control of hemoglobin levels at extended administration intervals compared to darbepoetin alfa. The purpose of this study was to compare the patterns of use, efficiency of therapy and cost with undergoing hemodialysis patients. Electronic medical record system was used to examine administration frequency, hemoglobin response rate, achievement of target hemoglobin, drug costs. Administration frequency was once in 4 weeks with methoxy polyethylene glycol epoetin beta group and 3 times in 4 weeks with darbepoetin alfa group. Hemoglobin response rate was 61.5% in methoxy polyethylene glycol epoetin beta at the time of 16 weeks. It was not significantly different from 66.7% in darbepoetin alfa （P = 1.000）. The drug cost for methoxy polyethylene glycol epoetin beta group was little higher than darbepoetin alfa group. However, there was no statistically significant difference （P = 0.164）. Use of methoxy polyethylene glycol epoetin beta is as effective and safe as darbepoetin alfa managing renal anemia in hemodialysis patients. Methoxy polyethylene glycol epoetin beta＇s extended administration interval improve patient＇s compliance and enable effective anemia treatment.

Preparation and Characterization of Polymeric Micelles from Poly (D, L-lactide) and Methoxypolyethylene Glycol Block Copolymers as Potential Drug Carriers

Amphiphilic diblock copolymers composed of methoxy polyethylene glycol （MePEG） and poly（D,L-lactide） （PDLLA） were prepared for the preparation of polymeric micelles, The use of MePEG-PDLLA as drug carriers has been reported in the open literature, but there are only few data on the application of a series of MePEG-PDLLA copolymers with different lengths in the medical field, The shape of the polymeric micelles is also important in drug delivery, Studies on in vitro drug release profiles require a good sink condition. The critical micelle concentration of a series of MePEG-PDLLA has a significant role in drug release. To estimate their feasibility as a drug carrier, polymeric micelles made of MePEG-PDLLA block copolymer were prepared by the oil in water （O/VV） emulsion method. From dynamic light scattering （DLS） measurements, the size of the micelle formed was less than 200 nm, The critical micelle concentration of polymeric micelles with various compositions was determined using pyrene as a fluorescence probe. The critical micelle concentration decreased with increasing number of hydrophobic segments. MePEG-PDLLA micelles have a considerably low critical micelle concentration （0.4～0.5 μg/mL）, which is apparently an advantage in utilizing these micelles as drug carriers. The morphology of the polymeric micelles was observed using scanning electron microscopy （SEM） and transmission electron microscopy （TEM）, The micelles were found to be nearly spherical. The yield of the polymeric micelles obtained from the O/W method is as high as 85%.

Preparation of pegylated lumbrokinase and an evaluation of its thrombolytic activity both in vitro and in vivo

Lumbrokinase(LK)is a group of serine proteases with strong fibrinolytic and thrombolytic activities.In clinical practice,LK can only be administered orally because of its antigenicity,iinmunogenicity and potential to produce anaphylactic reactions after injection.However,many useful drugs such as interferon,insulin,erythropoietin and interleukin have been modified with polyethylene glycol(PEG)to prepare injectable formulations.In this study,LK was modified with methoxy PEG succinimidyl carbonate(mPEG-SC)with molecular weights of 5000,10,000 and 20,000 and the pegylatcd products were isolated and purified using the Akta protein purification system.The extent of pegylation was detennined by HPLC.Fibrinolytic activities of pegylatcd and unmodified LK were measured both in vitro against urokinase on fibrin plates and in vivo using a mouse carageenan black tail model.Optimal pegylation was obtainal using mPEG-SC_(5000) in a buffer pH 8.0 with a reaction time of 5 h,reaction temperature of 0℃ and LK:mPEG-SC molar ratio of 1:25.The results show that mPEG modified LK has strong fibrinolytic and thrombolytic activities both in vitro and in vivo.It is suggested that the pegylatcd LK is a promising injectable thrombolytic agent for the treatment of thrombotic diseases in clinical practice.

Preparation and characterization of m PEG grafted chitosan micelles as 5-fluorouracil carriers for effective anti-tumor activity

The objective of this study was to investigate the potential of methoxy polyethylene glycol（m PEG）grafted chitosan（m PEG-g-CS） to be used as a drug carrier. m PEG-g-CS was successfully synthesized by one-step method with formaldehyde. The substitution degree of m PEG on chitosan was calculated by elemental analysis and was found to be（3.23 0.25）%. m PEG-g-CS self-assembled micelles were prepared by ultrasonic method with the controlled size of 178.5–195.1 nm and spherical morphology. Stable dispersion of the micelles was formed with the zeta potential of 2.3–30.2 m V. 5-Fluorouracil（5-FU）, an anticancer chemotherapy drug, was used as a model drug to evaluate the efficiency of the new drug delivery carrier. The loading efficiency of 5-FU was（4.01 0.03）%, and the drug-loaded m PEG-g-CS self-assembled micelle showed a controlled-release effect. In summary, the m PEG-g-CS self-assembled micelle is proved to be a promising carrier with controlled particle size and controlled-release effect. Therefore, it has great potential for the application as 5-FU carriers for effective anti-tumor activity.