[Preparation and characterization of paclitaxel microspheres in situ gel and its antitumor efficacy by local injection].

OBJECTIVE: The current difficulties in the treatment of tumor include repeated administration and high recurrence rate after tumor resection. In order to reduce the number of doses, avoid side effects of chemotherapeutic drugs, suppress tumor growth and delay tumor recurrence after surgery, a temperature-sensitive in situ gel with paclitaxel microspheres (PTX/M gel) was prepared. PTX/M gel was administered by intratumoral injection once a month. METHODS: First of all, paclitaxel microspheres (PTX/M) were prepared by emulsion solvent evaporation method. A laser particle size distribution analyzer was used to investigate the size, distribution, specific surface area of microspheres. Paclitaxel content was determined by high performance liquid chromatography (HPLC). Then encapsulation efficiency of paclitaxel was calculated and in vitro release characteristics were studied. Secondly, PTX/M gel was prepared by cold dissolution method. The phase transition temperature, elastic modulus, dissolution curve, correlation between dissolution and release were measured. Finally, U87 MG and 4T1 subcutaneous tumor models were established respectively to study the efficacy of PTX/M gel in suppressing tumor growth and delaying tumor recurrence after surgery. RESULTS: The median diameter of the selected PTX/M was (32.24±1.09) µm, the specific surface area was (206.61±10.23) m2/kg, the encapsulation efficiency was 85.29%±1.34%, and the cumulative release percentage of paclitaxel from PTX/M was 33.56%±3.33% in one month. Phase transition temperature of PTX/M gel was 33 °C. The elastic modulus of PTX/M gel at 25 °C and 37 °C were 4.2×103 Pa and 18×103 Pa, respectively. The gel could stay in the body for up to 48 hours. It could be seen from the results of animal experiments that were compared with the saline group and the Taxol group, and the tumor-bearing mice of the PTX/M gel group had the slowest tumor growth (P<0.05). Similarly, in the tumor recurrence experiments, the mice of PTX/M gel group had the latest tumor recurrence after surgery. CONCLUSION: As a local sustained-release preparation, PTX/M gel can effectively suppress tumor growth and delay postoperative recurrence of tumors. It has potential advantages in tumor treatment.

[Study on the properties of felodipine solid dispersions prepared by different technologies].

OBJECTIVE: To prepare felodipine/copovidone solid dispersions, which were made based on different preparation technologies. Insoluble felodipine was selected as the model drug in this research. This drug belonged to Biopharmaceutics Classification System II (BCSII) with insoluble property and good permeability across intestinal mucosa simultaneously. A comparative study was carried out for further investigating their corresponding pharmaceutical properties. METHODS: Felodipine/copovidone solid dispersions were achieved by four methods including spray-drying method, microwave-induced fusion quench cooling method, freeze-drying method and co-precipitation method. These solid dispersions were produced based on corresponding processes that corresponded to these methods. Internal properties of co-povidone solid dispersions were analyzed by various approaches including scanning electron microscope (SEM), differential scanning calorimetry (DSC) and powder X-ray diffraction (PXRD). The improvement on insoluble properties of felodipine by solid dispersions produced by different technologies was characterized by dissolution experiments based on dissolution instrument. Crystallization inhibition effect of polymers against drugs was studied by supersaturated experiments through determining the concentration value at different time points. RESULTS: The internal drug was dispersed in amorphous form in solid dispersions produced by spray-drying, microwave method, microwave/quench-cooling method and co-precipitation method. Freeze-drying method resulted in a form of crystal in felodipine/copovidone solid dispersions. Compared with other technologies, microwave-induced quench cooling method could significantly improve the dissolution of insoluble drug felodipine (P<0.05). The dissolution concentration reached approximately 4.65 mg/L at 60 min time point. Copovidone could inhibit or retard the crystallization of felodipine in a supersaturated state. In the solution pre-dissolved with maximum copoyidone polymer, the minimum crystallization rate of supersaturated felodipine was observed at 240 min time point. The value of crystallization rate was 0.19 mg/(L×min). CONCLUSION: The study is helpful to understand and clarify the internal properties of solid dispersions obtained by different technologies. The research also provides beneficial consultation for the choice of technology in practical production of drug-polymer solid dispersions.

[Health economic evaluation of a 23 value pneumococcal polysaccharide vaccination pilot programme among elderly chronic obstructive pulmonary disease patients in China].

Objective: From the perspective of health economics, to evaluate 23 pneumococcal polysaccharide vaccination programme among chronic obstructive pulmonary disease (COPD) patient. Methods: In the pilot counties of the project of integrated care pathway for COPD patient (Hanbin district of Hanzhong city in Shanxi Province, Qianjian district of Qingqing city, Huandao district of Qindao city in Shangdong Province, Wen county of Jiaozuo city in Henan Province), information of insurance participants of New Rural Cooperative Medical System (NRCS) was collected by local NRCM information system, which included general information as well as records of medical care and medical fee. Nonprobability sampling method was applied to select a total of 860 objects, who were over 60 years old with local household registration, hospitalized within one recent year due to COPD acute exacerbation, and without vaccination of 23 voluntary pneumococcal polysaccharide vaccine within 3 years. A quasi-experimental design without control group was adopted. Objects were vaccinated with 23-valent pneumococcal polysaccharide vaccine from January to December in 2013, then were followed up from January in 2014 for one year. Data of effectiveness and medical cost was collected by self-designed questionnaire and (Chinese version). Paired rank sum test applied to test the difference of quality of life, number and direct medical cost of treatment (including outpatient treatment and hospitalization) due to COPD acute exacerbation, one year before and after intervention. The incremental cost-effectiveness ratio (ICER) and cost-benefit ratio (CBR) of the programme were calculated. Results: By January 2014, eight hundred sixty objects were vaccinated. By January 2015, seven hundred eighty eight objects were followed up, with 72 cases withdrawed (8.4%). On average, COPD patients reduced 1.12±2.51 treatments due to acute exacerbation, including 0.28±2.09 outpatient treatments and 0.85±1.15 hospitalizations. Total medical cost was saved by 3 610.21 per capita yuan, including outpatient cost of 241.41 yuan and hospitalization cost of 269.82 yuan; Quality of life was gained by 0.03 QALY gain per capita. The ICER was dominant and CBR was 12.00. Conclusion: COPD patients vaccinated with 23-valent pneumococcal polysaccharide vaccine within one year reduced treatments due to acute exacerbation. The vaccination was cost effective and cost saving , and we suggest the vaccine should be covered in the public health program or health insurance scheme in conditional region.

Efficient inhibition of cisplatin-resistant human ovarian cancer growth and prolonged survival by gene transferred vesicular stomatitis virus matrix protein in nude mice.

BACKGROUND: The vesicular stomatitis virus matrix protein (VSVMP) has been receiving attention as an anticancer agent because of its ability of inducing apoptosis. MATERIALS AND METHODS: Nude mice bearing A2780s and A2780cp ovarian tumors were treated twice weekly with i.v. administration of 50 microg VSVMP/250 mug liposome complex, 50 microg empty plasmid/250 microg liposome complex, 0.9% NaCl solution or weekly with i.p. administration of cisplatin (5 mg/kg) for 3 weeks. Tumor volume and survival time were observed. TUNEL assay and CD34 vessel staining were conducted in tumor tissue. Antiangiogenesis in vivo were determined by sponge assay. Antiproliferative and apoptosis-inducing activities of VSVMP in vitro were tested on MS1 murine endothelial cells and four human ovarian cancer cell lines: A2780s, A2780cp, HO8910 and COC1. RESULTS: Administration of VSVMP resulted in significant inhibition (87%-98% maximum inhibition relative to controls) in the growth of A2780s and A2780cp tumor xenografts, and prolonged the survival of the treated mice. Complete tumor regression happened in VSVMP-treated mice in both tumor models. These antitumor responses were associated with marked increases in tumor apoptosis and reductions in intratumoral microvessel density. CONCLUSIONS: Our data indicate that VSVMP may provide an effective approach to inhibit both cisplatin-sensitive and -resistant human ovarian cancer growth with minimal side-effects.

Prefrontal alterations in GABAergic and glutamatergic gene expression in relation to depression and suicide.

People that committed suicide were reported to have enhanced levels of gene transcripts for synaptic proteins in their prefrontal cortex (PFC). Given the close association of suicide with major depressive disorder (MDD), we here assessed whether these changes are related to suicide or rather to depression per se. We used quantitative PCR to determine mRNA levels of 32 genes encoding for proteins directly involved in glutamatergic or GABAergic synaptic transmission in postmortem samples of the anterior cingulate cortex (ACC) and the dorsolateral PFC (DLPFC). Seventy-two brain samples from 3 groups of subjects were derived from the Stanley Medical Research Institute (SMRI): i) patients with MDD who committed suicide (MDD-S), ii) MDD patients who died of non-suicidal causes (MDD-NS) and iii) age-matched, non-psychiatric control subjects. In the ACC, a significantly enhanced expression of genes related to glutamatergic or GABAergic synaptic transmission was found only in MDD-S patients, whereas in MDD-NS patients, decreased levels for these transcripts were found. Moreover, in the DLPFC, expression of these genes was decreased in MDD-S, relative to MDD-NS patients, whereas both groups showed increased expression compared to control subjects. In conclusion, our findings indicate that MDD is associated with increases in GABA and glutamate related genes in the DLPFC (irrespective of suicide), while in the ACC, the increase in GABA and glutamate related genes may relate to suicide, rather than to MDD per se.

Prefrontal changes in the glutamate-glutamine cycle and neuronal/glial glutamate transporters in depression with and without suicide.

There are indications for changes in glutamate metabolism in relation to depression or suicide. The glutamate-glutamine cycle and neuronal/glial glutamate transporters mediate the uptake of the glutamate and glutamine. The expression of various components of the glutamate-glutamine cycle and the neuronal/glial glutamate transporters was determined by qPCR in postmortem prefrontal cortex. The anterior cingulate cortex (ACC) and the dorsolateral prefrontal cortex (DLPFC) were selected from young MDD patients who had committed suicide (MDD-S; n = 17), from MDD patients who died of non-suicide related causes (MDD-NS; n = 7) and from matched control subjects (n = 12). We also compared elderly depressed patients who had not committed suicide (n = 14) with matched control subjects (n = 22). We found that neuronal located components (EAAT3, EAAT4, ASCT1, SNAT1, SNAT2) of the glutamate-glutamine cycle were increased in the ACC while the astroglia located components (EAAT1, EAAT2, GLUL) were decreased in the DLPFC of MDD-S patients. In contrast, most of the components in the cycle were increased in the DLPFC of MDD-NS patients. In conclusion, the glutamate-glutamine cycle - and thus glutamine transmission - is differentially affected in depressed suicide patients and depressed non-suicide patients in an area specific way.

Different stress-related gene expression in depression and suicide.

OBJECTIVE: Suicide occurs in some, but not all depressed patients. So far, it remains unknown whether the studied stress-related candidate genes change in depression, suicide or both. The prefrontal cortex (PFC) is involved in, among other things, impulse control and inhibitory behavior and plays an important role in both suicide and depression. METHODS: We have employed qPCR to study 124 anterior cingulate cortex (ACC) and dorsolateral PFC (DLPFC) brain samples, obtained from two brain banks, from: i) young depressed patients (average age 43 years) who committed suicide (MDD-S) and depressed patients who died from causes other than suicide (MDD-NS) and from ii) elderly depressed patients (average age 75 years) who did not commit suicide (DEP). Both cohorts were individually matched with non-psychiatric non-suicide control subjects. We determined the transcript levels of hypothalamic-pituitary-adrenal axis-regulating molecules (corticotropin-releasing hormone (CRH), CRH receptors, CRH binding protein, mineralocorticoid receptor/glucocorticoid receptor), transcription factors that regulate CRH expression, CRH-stimulating cytokines, chaperone proteins, retinoid signaling, brain-derived neurotrophic factor and tropomyosin-related kinase B, cytochrome proteins, nitric oxide synthase (NOS) and monoamines. RESULTS: In the MDD-S group, expression levels of CRH and neuronal NOS-interacting DHHC domain-containing protein with dendritic mRNA (NIDD) were increased. Other changes were only present in the DEP group, i.e. decreased NIDD, and increased and 5-hydroxytryptamine receptor 1A (5-HT1A) expression levels. Changes were found to be more pronounced in the anterior cingulate cortex than in the dorsolateral PFC. CONCLUSION: Depressed patients who committed suicide have different gene expression patterns than depressed patients who died of causes other than suicide.

Remote loading of diclofenac, insulin and fluorescein isothiocyanate labeled insulin into liposomes by pH and acetate gradient methods.

Remote loading of the model drugs diclofenac, insulin and fluorescein isothiocyanate labeled insulin (FITC-insulin) into liposomes by formation of transmembrane gradients were examined. A trapping efficiency of almost 100% was obtained for liposomal diclofenac, by the calcium acetate gradient method, whereas liposomes prepared by the conventional reverse-phase evaporation vesicle method had 1-8% trapping efficiencies. Soybean-derived sterol was a better stabilizer of the dipalmitoylphosphatidylcholine bilayer membrane than cholesterol, as shown from trapping efficiencies and drug release. The pH gradient method resulted in a 5-50% of FITC-insulin liposomal trapping efficiency, while insulin could not be loaded by this method. Liposomes released calcein in response to insulin, showing insulin interacts with the liposomal membrane in the presence of a transmembrane gradient. The present work has demonstrated a remote loading method for weak acids such as diclofenac into liposomes by the acetate gradient method. From the result of remote loading of FITC-insulin into liposomes by the pH gradient method, this method may be available for the preparation of liposomal peptides.

[Studies on pharmacokinetics of cisplatin-ethylcellulose microspheres for maxillary arterial embolization in dogs].

This paper reports the preparation and pharmacokinetic studies of DDP-EC-ms. The DDP-EC-ms were infused into the maxillary artery of dogs and DDP were infused into the vein as control. The concentration of DDP in peripheral venous blood and tissue was determined by FAAS. Results showed that the DDP level of DDP-EC-ms in the circulating blood was significantly lower than that in dogs given DDP intravenously. However, a significantly higher DDP concentration in tissues was found in dogs treated with DDP-EC-ms. These facts suggest that maxillary arterial embolization with DDP-EC-ms, which significantly reduced the systematic side effects and increased the level of DDP in the embolized local tissue, could achieve the purpose of targeted cancer therapy.

[Structure characteristics of insulin liposomes].

AIM: To study the molecular location and state of insulin within insulin-lipids. METHODS: Particle size and distribution of insulin-lipids was determined by using laser light scattering instrument, and transmission electron microscopy (TEM) was used to examine the morphology of insulin-lipids. HPLC, fluorescence scanning, digestion with trypsin and polyacrylamide gel electrophoresis was used to determine the molecular localization and state of insulin in the lipids. RESULTS: The mean particle size, polydispersity and sample quality were 218.3 nm, 0.073 and 7.2 respectively. The results of HPLC determination showed insulin exist in the insulin-lipids. There was no insulin emission spectrum in the insulin-lipids fluorescence spectrum; nearly no insulin digested in the test of insulin digestion by trypsin, and no insulin band in the insulin-lipids in figure of polyacrylamide gel electrophoresis. CONCLUSION: Insulin was encapsulated within lipids.

[Interactions of insulin with dipalmitoylphosphatidylcholine liposomes].

AIM: To study the interactions of insulin with dipalmitoylphosphatidylcholine liposomes. METHODS: The liposomes were prepared by reverse-phase evaporation vesicle method. The entrapped efficiency, size and distribution of the liposomes were determined, and the influences of insulin on entrapped efficiency, size and distribution of the liposomes were investigated. The influences of liposomes on the fluorescence emission spectra of insulin and the calcein leakage from the liposomes entrapped calcein induced by insulin were measured. RESULTS: Insulin has little influence on the size and distribution of the liposomes while the sizes of the liposomes were about 170-190 nm. The insertion of tyrosine of insulin into dipalmitoylphosphatidylcholine liposomes membrane was not deep. The insulin disturbed the liposomes membrane, induced the calcein leakage from the calcein-loaded liposomes. CONCLUSION: Amphiphilic, example insulin, may disturb the intact membrane of liposome through the interaction either hydrophobic or hydrophilic. The attention should be paid to the entrapment process of peptides into liposomes.

All-trans retinoic acid-induced hypothalamus-pituitary-adrenal hyperactivity involves glucocorticoid receptor dysregulation.

Clinical reports have highlighted a role for retinoids in the etiology of mood disorders. Although we had shown that recruitment of the nuclear receptor retinoic acid receptor-α (RAR-α) to corticotropin-releasing hormone (CRH) promoter is implicated in activation of the hypothalamus-pituitary-adrenal (HPA) axis, further insight into how retinoids modulate HPA axis activity is lacking. Here we show that all-trans retinoic acid (RA)-induced HPA activation involves impairments in glucocorticoid receptor (GR) negative feedback. RA was applied to rats chronically through intracerebroventricular injection. A 19-day RA exposure induced potent HPA axis activation and typical depression-like behavior. Dexamethasone failed to suppress basal corticosterone (CORT) secretion, which is indicative of a disturbed GR negative feedback. In the hypothalamic paraventricular nucleus, increased CRH⁺ and c-fos⁺ cells were found while a negative R-2⁺/ER⁺ correlation was present between the number of RAR-α⁺ and GR⁺ cells. This was paralleled by increased RAR-α and decreased GR protein expression in the hypothalamus. Additional in vitro studies confirmed that RA abolished GR-mediated glucocorticoid-induced suppression of CRH expression, indicating a negative cross-talk between RAR-α and GR signaling pathways. Finally, the above changes could be rapidly normalized by treatment with GR antagonist mifepristone. We conclude that in addition to the 'classic' RAR-α-mediated transcriptional control of CRH expression, disturbances in GR negative feedback constitute a novel pathway that underlies RA-induced HPA axis hyperactivity. The rapid normalization by mifepristone may be of potential clinical interest in this respect.

Gene expression of GABA and glutamate pathway markers in the prefrontal cortex of non-suicidal elderly depressed patients.

BACKGROUND: The prefrontal cortex (PFC) is presumed to be involved in the pathogenesis of depression. METHODS: We determined the gene expression of 32 markers of the pathways of the two main neurotransmitters of the PFC, gamma-aminobutyric acid (GABA) and l-glutamic acid (glutamate), by real-time quantitative PCR in human postmortem anterior cingulate cortex (ACC) and dorsolateral PFC (DLPFC) in elderly non-suicidal patients with major depressive disorder (MDD) or bipolar disorder (BD). RESULTS: We found the transcript levels of GABA(A) receptor beta 2 (GABRB2) and post-synaptic density-95 (PSD-95) to be significantly decreased in the ACC in mood disorder. DLPFC mRNA expression of all the detected genes in the mood disorder group did not differ significantly from that of the non-psychiatric controls. LIMITATIONS: Several inherent and potentially confounding factors of a postmortem study, such as medication and cause of death, did not seem to affect the conclusions. The group size was relatively small but well documented, both clinically and neuropathologically. CONCLUSIONS: The observed alterations in the GABAergic and glutamatergic pathways indicate a diminished activity. These alterations were only present in the ACC and not in the DLPFC.

Acute restraint stress increases intrahypothalamic oestradiol concentrations in conjunction with increased hypothalamic oestrogen receptor ß and aromatase mRNA expression in female rats.

Activation of the hypothalamic-pituitary-adrenal axis is considered to be one of the key physiological responses to stress and, interestingly, shows a marked sex difference. Oestradiol plays an important role in this sex difference. The present study investigated the systemic and intrahypothalamic oestradiol response to physical restraint stress in female rats. We used jugular catheterisation and intrahypothalamic microdialysis to simultaneously measure plasma oestradiol and local oestradiol concentrations in the paraventricular nucleus (PVN) of the hypothalamus. We also assessed corticotrophin-releasing hormone (CRH), aromatase, and oestrogen receptor (ER) α and ß mRNA expression in the PVN by quantitative polymerase chain reaction immediately after the acute stress period. As expected, PVN CRH mRNA and plasma corticosterone were significantly increased after acute stress. Interestingly, the local oestradiol concentration in the PVN also increased during the 1-h stress period in pro-oestrus and in ovariectomised (OVX) animals. Aromatase mRNA expression in the PVN was increased markedly in pro-oestrus but only modestly in oestrus. PVN ERß but not ERα mRNA expression was significantly elevated in pro-oestrous animals. In addition, plasma oestradiol levels increased 10 min after stress, both during pro-oestrus and oestrus but not in OVX animals. To conclude, we report an intra-hypothalamic oestradiol response to restraint stress. The rising hypothalamic oestradiol concentration together with increased ERß gene expression indicates a positive feedback of hypothalamic oestradiol signalling during acute stress in rats.

Measurement of the K0 charge radius and a CP-violating asymmetry and a search for CP-violating E1 direct photon emission in the rare decay KL--> pi+ pi- e+ e-.

Using the complete KTeV data set of 5,241 candidate K(L)--> pi(+) pi(-) e(+) e(-) decays (including an estimated background of 204 +/- 14 events), we have measured the coupling g(CR)= 0.163 +/- 0.0149(stat) +/- 0.023(syst) of the CP conserving charge radius process and from it determined a K(0) charge radius of = [-0.077 +/- 0.007(stat) +/- 0.011(syst)]fm(2). We have determined a first experimental upper limit of 0.04 (90% C.L.) /g(e1)/ / /g(M1)/ of the couplings for the E1 and M1 direct photon emission processes. We also report the measurement of /g(M1)/ including a vector form factor /g(M1)/(1 + (a(1)/a(2))/((M(2)(p)-(M(2)(k))= 2M(K)E(gamma*)), where vector /g(M1)/= 1.11+/- 0.12(stat) +/- 0.08(syst) and a(1)/a(2) = [-0.744 +/- 0.027(stat) +/- 0.032(syst)] GeV(2)/c(2). Finally, a CP-violating asymmetry of [13.6 +/- 1.4(stat) +/- 1.5(syst)]% in the CP and T odd angle phi between the decay planes of the e(+) e(-) and pi(+) pi(-) pairs in the K(L) center of mass is reported.

Observation of the decay xi0 --> sigma+ mu- nu(mu).

The xi0 muon semileptonic decay has been observed for the first time with nine identified events using the KTeV beam line and detector at Fermilab. The decay is normalized to the xi0 beta decay mode and yields a value for the ratio of decay rates gamma(xi0 --> sigma+ mu- nu(mu))/gamma(xi0 --> sigma+ e- nu(e)) of [1.8(-0.5)(+0.7)(stat) +/- 0.2(syst)] x 10(-2). This is in agreement with the SU(3) flavor symmetric quark model.

Rates of systemic degradation and reticuloendothelial system uptake of calcein in the dipalmitoylphosphatidylcholine liposomes with soybean-derived sterols in mice.

The systemic degradation and the reticuloendothelial system (RES) uptake of calcein entrapped in dipalmitoylphosphatidylcholine (DPPC) liposomes with soybean-derived sterols (SS) were examined after intravenous administration to mice by measuring the free and liposomal calcein levels in the blood. The results indicate that the rates of systemic degradation and the RES uptake of liposomes decrease with the addition of SS in DPPC liposomes since the SS has the ability to stabilize the liposomes. The rate of uptake by RES is larger than the rate of systemic degradation. The rate of leakage of calcein from liposomes by incubation in plasma in vitro is almost the same as that of systemic degradation in vivo.

Effects of orally administered liposomes with soybean-derived sterols and their glucosides on rat body weight.

The effects on Wistar rat body weight were examined after a single subcutaneous (s.c.) or oral (p.o.) administration of dipalmitoylphosphatidylcholine (DPPC) liposomes composed of soybean-derived sterols (SS) and their glucosides (SG) with or without entrapping recombinant human erythropoietin (Epo) for 1 week. Body weight increased significantly after both types of administration compared with the control groups irrespective of the existence of Epo. The neutral lipid concentration in plasma increased with the increase in body weight whereas the total contents of cholesterol and high density lipoprotein cholesterol in the plasma did not change significantly. The SS and SG suspensions following p.o. administration, however, did not alter the body weight. These findings suggest that liposomal SS and SG may be absorbed through the intestinal membrane and induce a change in the uptake of lipid, in contrast to the suspension state. SS in liposomes significantly increased body weight more than SG after p.o. administration.

Evaluation of liposomal erythropoietin prepared with reverse-phase evaporation vesicle method by subcutaneous administration in rats.

We encapsulated erythropoietin (Epo) in dipalmitoylphosphatidylcholine (DPPC) liposomes with soybean-derived sterols (SS-liposomes) and its glucoside (SG-liposomes) by reverse-phase evaporation vesicle method, and evaluated them by subcutaneous administration in rats. With 4 min of sonication, the damage to Epo activity was observed mainly in the non-encapsulated Epo in the liposomes. This study indicated that the bilayer of liposomes had the ability to protect the Epo activity, by reducing the aggregation that was caused by interaction between Epo molecules. The SG-liposomes had a higher retention of the Epo activity the SS-liposomes. 25.3% or 33.6% of activity was retained by SS-liposomes under the conditions of 4 min or 1 min of sonication, while 53.3% or 58.3% of the activity was retained by SG-liposomes under the same conditions. Shorter sonication was available to minimize the loss of the Epo activity. Epo in SG-liposomes appeared to increase the activity.