Determination of related substances in ketoprofen injection by RP-HPLC method.

The paper aims to establish a RP-HPLC method for the simultaneous determination of six related substances in ketoprofen injection. The separation was performed on a VP-ODS C18 column (4.6mm×250mm, 5µm) with the mobile phase of 6.8% phosphate buffer solution (adjusted to pH3.5 with 85% phosphoric acid)-acetonitrile-water (2:43:55,v/v/v) at a flow rate of 1.2mL•min-1. The detection wavelength and the injection volume were set at 233nm and 20µL, respectively. Impurity A and C were calculated by external standard method. Main component self-compare method with calibration factor was used to calculate impurity B, D, E, F and main component self-compare method without calibration factor was used to calculate unspecified impurity. Related substances and degraded substances were completely separated from ketoprofen. For impurity A and C, the linear range of determination were separately 0.06 µg•mL-1 ~ 3.6µg•mL-1 and 0.036µg•mL-1 ~ 2.4µg•mL-1 with the correlation coefficient of 0.9999. The average recoveries (n=9) were 98.13% (RSD=0.35%) and 96.32% (RSD=0.43%). The precision and repeatability for method were good. With reference to ketoprofen (retention time =10.06 min), the relative retention time of impurity B, D, E, F were 0.71, 1.46, 0.59, 2.13, respectively, and the relative correction factors were 0.962, 0.938, 0.957, 0.960, respectively. Finally, determined that the contents of impurity A could not be more than 0.3%, any of the contents of impurity B, C, D, E, F and unspecified impurities could not be more than 0.2%, sum of the contents of impurities other than A and C couldn't be more than 0.5%. The method was proved to be simple, rapid, accurate, sensitive and suitable for the simultaneous determination of six related substances in ketoprofen injection.

Enhanced Peptide delivery into cells by using the synergistic effects of a cell-penetrating Peptide and a chemical drug to alter cell permeability.

Cell-penetrating peptides (CPPs) are short, often hydrophilic peptides that can deliver many kinds of molecules into cells and that are likely to serve as a useful tool of future biotherapeutics. However, CPPs application is limited because of insufficient transduction efficiency and unpredictable cellular localization. Here, we investigated the enhancement of 1,2-benzisothiazolin-3-one (BIT) on the uptake of a synthetic fluorescent TAT and a TAT-conjugated green fluorescent protein (GFP) or pro-apoptotic peptide KLA and evaluated its toxicity in various cell lines. Our results showed that BIT pretreatment can enhance the penetration efficiency of TAT and its fusion peptide. In addition, the fluorescence of the peptide conjugate at effective doses was well-distributed in the intracellular of different cell lines without membrane perforation or detectable cytotoxicity. The internalization of the peptides was serum-dependent and temperature-independent. These findings imply that BIT may serve as a newly found delivery enhancer that is suitable for improving the penetration of CPPs.

Design and content determination of nimesulide injectable formulation.

The aim of the present study was to formulate Nimesulide inject able solution, establish a method for content determination, and accumulate data for registration of a new Nimesulide formulation. The optimal Nimesulide inject able formulation was determined based on the results of single factor test and orthogonal test. Moreover, clarity, stability, pH, content and related substances of Nimesulide were used as the main study indicators. The content of Nimesulide in inject able solution was determined by the high performance liquid chromatography (HPLC) method. The mobile phase consisted of V (methanol): V (potassium dihydrogen phosphate, pH 4.2)=60:40 at a flow rate of 1.0 mL/min. The detection was carried out with UV detector (λ(max) =254 nm) under a column temperature of 25°C and an injection volume of 20µL. The optimal inject able formulation was 4% Nimesulide, 4% ethanolamine, 0.1% L-cysteine, 0.01% EDTA-2Na, a suitable amount of lactic acid and water for injection. Nimesulide detection limits range from 20 to 80 µg/mL with a correlation coefficient of 0.9995 and high average recovery 99.91% (RSD=0.06%). In conclusion, the formulation was suitable for Nimesulide inject able form, and the determination method was simple, sensitive and accurate. Therefore, the Nimesulide inject able formulation can be used for industrial production and effectively controlled.

Protective effects of berberine on doxorubicin-induced hepatotoxicity in mice.

Doxorubicin, a very potent and often used anti-cancer drug, is largely limited due to the dose-related toxic effects. The present study investigated whether berberine, a natural product alkaloid, can reduce the liver injury induced by doxorubicin. Mice of either gender were randomly divided into four groups: the control group, doxorubicin group, berberine group, and berberine+doxorubicin group. In the tests, body weight, general condition and mortality of the mice were observed, and serum alanine aminotransferase and aspartate transaminase levels were determined to evaluate liver function. Furthermore, the liver was excised for determination of the weight changes, as well as histopathological analysis in the tissues. Mortality rate and significant decline in body weight, and increased plasma alanine aminotransferase and aspartate transaminase activities were observed in doxorubicin-treated mice. These changes were significantly prevented by pretreatment with berberine. Histopathological studies showed that doxorubicin caused structural injuries, such as vascular congestion, inflammatory cell infiltration, hepatocellular degeneration and necrosis, fibrosis in the liver. These histopathological changes were largely attenuated by berberine pretreatment. These findings indicate that berberine has the hepatoprotective effect on doxorubicin-induced liver injury in mice.

Characterization of conformation-specific monoclonal antibodies against rabies virus nucleoprotein.

Three anti-rabies virus (RABV) nucleoprotein (N) monoclonal antibodies (Mab) were characterized by immunofluorescence assays, western blotting, and immunohistochemistry. One of these Mabs recognized the antigen by all of the assays, while the other two recognized N only in the native form in the immunofluorescence assay. These data, together with epitope mapping studies, suggest that two anti-N Mabs recognize conformational epitopes located within the N-terminal region of the RABV N protein. The availability of Mabs specific for both linear and epitope-specific antibodies should prove valuable for rabies diagnosis as well as for RABV N protein structure-function studies.

Stimuli-responsive polymeric prodrug-based nanomedicine delivering nifuroxazide and doxorubicin against primary breast cancer and pulmonary metastasis.

Functionalized drug delivery systems against malignant lung metastasis of breast cancer have been extensively studied, while metastasis remains a challenging issue. We propose a new strategy to achieve eradication of primary breast cancer cells and inhibition of pulmonary metastasis. A cathepsin B/pH dual-sensitive block copolymer with a molecular weight of 92 kDa was synthesized to conjugate with doxorubicin (DOX). The copolymer-DOX was further loaded with nifuroxazide (NFX) to self-assemble co-prodrug-loaded micelles (CLM). CLM displayed a drug release pattern in response to pH/enzyme dual stimuli and was enzymatically biodegradable. CLM was demonstrated to reduce viability and inhibit migration and invasion of 4T1 murine breast cancer cells in vitro. After i.v. injection of CLM, its nanoscale size and stimuli-responsiveness facilitated delivery of drugs to the tumor site in mice. Enhanced anti-tumor efficacy and great anti-metastatic effects were found in both orthotropic and lung metastasis 4T1 breast cancer mice models. Meanwhile, histological immunofluorescence and immunohistochemical analyses revealed a high level of apoptosis, suppressed expression of matrix metalloproteinases and reduction in MDSCs infiltration, and all these contributed to inhibit pulmonary metastasis. CLM may be explored as a potential nanomedicine against breast cancer metastasis.

Thermosensitive nanocomposite gel for intra-tumoral two-photon photodynamic therapy.

We propose here a new approach to achieve intratumoral near-infrared (NIR) two-photon photodynamic therapy (PDT). We established a composite micellar thermosensitive hydrogel made of clinically approved methoxy poly(ethylene glycol)-polylactide copolymer (mPEG-PDLLA) and Pluronic (F127). The mPEG-PDLLA form micelles that can be loaded with two-photon absorption compound (T1) and photosensitizer (PS), The F127 micelles are liquid at room temperature and while forming an hydrogel at body temperature. This enables an in situ gelification upon injection providing long-term retentio within the tumor. The NIR light is thus upconverted into visible light by T1 and excited PS. The morphology, rheology properties and releasing profiles of hydrogel were fully characterized. The rheology properties and releasing mechanism was investigated. The composite hydrogel showed significant cytotoxicity to 4 T1 murine breast cancer cells upon NIR laser irradiation, while it showed non-significant cytotoxicity without. Time-dependent in vivo and ex vivo distribution results suggested that hydrogel administrated via intra-tumoral injection could prolong both PDT agents retention in tumor. We show here that the use of NIR radiation allows deep tissue penetration and inhibition of tumor growth of >50% even under 1 cm thick muscle tissue.

N-Benzyl-2-(2,6-dichloro-phen-oxy)-acetamide.

The structure determination of the title compound, C(15)H(13)Cl(2)NO(2), was undertaken as part of a project on the inter-action of small mol-ecules with proteins. In the crystal structure, the dihedral angle between the two aryl rings is 40.71 (11)°. The mol-ecules are connected via N-H⋯O hydrogen bonding into chains, which extend in the direction of the b axis.

Intracellular "activated" two-photon photodynamic therapy by fluorescent conveyor and photosensitizer co-encapsulating pH-responsive micelles against breast cancer.

The application of photodynamic therapy (PDT) for the diagnosis and treatment of cancer is hindered by the intrinsic defects of the currently available photosensitizers (PSs), such as poor water solubility and limited light-penetration depth. In this study, pH-responsive polymeric micelles that co-encapsulate therapeutic PSs and organooxotin two-photon compounds were applied for two-photon PDT (TP-PDT) against breast cancer. The TP-PDT effect of the drug-loaded micelles was "activated" when the micelles turned into aggregates at a triggering pH level. The in vitro therapeutic effect was evaluated on 4T1 murine breast cancer cells by viability assays, real-time morphology collapsing, and reactive oxygen species determination. Time-dependent ex vivo organ distribution and in vivo anticancer efficacy results suggested that the drug carriers could accumulate in tumors and suppress tumor growth by TP-PDT. The delivery system could enhance the solubility and distribution of PSs and, if administered along with a tissue-penetrating prolonged light source, could thus have good potential for cancer therapy.

Berberine sensitizes mutliple human cancer cells to the anticancer effects of doxorubicin in vitro.

The clinical use of doxorubicin (DOX), a potent antineoplastic agent, is limited by its serious side-effects, which include acute and chronic cumulative dose-related cardiotoxicity. Berberine (BER), a botanical alkaloid, has been reported to possess cardioprotective and antitumor effects. The 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-tetrazolium bromide (MTT) assay was used to detect the cell viability of A549, HeLa and HepG2 cells after each cell line was treated with DOX, BER or a combination of DOX and BER for 24 h. Apoptosis was evaluated by acridine orange staining. The results showed that BER and DOX exhibited dose-dependent inhibitory effects on A549 and HeLa cells which were likely mediated by inducing apoptosis. The same result was found in the combination group. Isobologram illustration and combination index (CI) analyses revealed that the combination of DOX and BER generates synergistic effects in A549 (CI=0.61) and HeLa (CI=0.73) cells. These findings indicate that BER sensitizes cells to the anticancer effects of DOX.

Capsaicin protects mice from community-associated methicillin-resistant Staphylococcus aureus pneumonia.

BACKGROUND: α-toxin is one of the major virulence factors secreted by most Staphylococcus aureus strains, which played a central role in the pathogenesis of S. aureus pneumonia. The aim of this study was to investigate the impact of capsaicin on the production of α-toxin by community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) strain USA 300 and to further assess its performance in the treatment of CA-MRSA pneumonia in a mouse model. METHODOLOGY/PRINCIPAL FINDINGS: The in vitro effects of capsaicin on α-toxin production by S. aureus USA 300 were determined using hemolysis, western blot, and real-time RT-PCR assays. The influence of capsaicin on the α-toxin-mediated injury of human alveolar epithelial cells was determined using viability and cytotoxicity assays. Mice were infected intranasally with S. aureus USA300; the in vivo protective effects of capsaicin against S. aureus pneumonia were assessed by monitoring the mortality, histopathological changes and cytokine levels. Low concentrations of capsaicin substantially decreased the production of α-toxin by S. aureus USA 300 without affecting the bacterial viability. The addition of capsaicin prevented α-toxin-mediated human alveolar cell (A549) injury in co-culture with S. aureus. Furthermore, the in vivo experiments indicated that capsaicin protected mice from CA-MRSA pneumonia caused by strain USA 300. CONCLUSIONS/SIGNIFICANCE: Capsaicin inhibits the production of α-toxin by CA-MRSA strain USA 300 in vitro and protects mice from CA-MRSA pneumonia in vivo. However, the results need further confirmation with other CA-MRSA lineages. This study supports the views of anti-virulence as a new antibacterial approach for chemotherapy.