Preparation and characterization of mucoadhesive enteric-coating ginsenoside-loaded microparticles.

Ginsenoside saponins are phytochemically extracted from red ginseng and have been regarded as the principal components manifesting the pharmacologic activities. Saponins are very soluble in water but poorly absorbed when orally administrated. Moreover, they have some disadvantages including the decomposition in acid medium. The aim of this study was to develop oral formulation of ginsenosides composed of enteric-coating polymer and mucoadhesive polymer considering the low stability in acid medium and the low permeability of saponins. Ginsenoside-loaded microparticles were prepared by spray dryer. The influences of various parameters such as the ratio of saponin to polymer, feed concentration, feed rate, inlet/outlet temperature and additional excipients during spray-drying were investigated. In vitro release profile of ginsenoside-loaded microparticles using additional excipients, ginsenoside saponin Rg1 or Rb1 showed an 18 or 13% release in pH 1.2 when ethyl cellulose was added. Also, ginsenoside-loaded microparticles exhibited mucoadhesive properties in the presence of chitosan. The application of these polymers is being considered as the potential strategy for improvement of bioavailability in saponin delivery, orally.

Diagnosis of a trocar site mass as omental herniation after laparoscopic gastrectomy.

A trocar site hernia is a rare complication. We report a patient who had an abdominal wall mass at a previous trocar site after laparoscopic distal gastrectomy. It was diagnosed as omental herniation and fat necrosis. We conclude that patients with trocar site masses exhibiting fat density on a computed tomography scan could be followed up without surgery, and that fascial defects located at 10-mm or larger trocar sites should be closed whenever possible to prevent hernia formation.

Hypoxia-inducible factor-1α and excision repair cross-complementing 1 in patients with small cell lung cancer who received front-line platinum-based chemotherapy: a retrospective study.

INTRODUCTION: Hypoxia-inducible factor-1α (HIF-1α), which plays an essential role in the adaptive response of cells to hypoxia, is associated with aggressive tumor behavior. Furthermore, a relationship between excision repair cross-complementing 1 (ERCC1) expression and platinum resistance has been reported in patients with various malignancies. The aim of this study was to investigate the expression of HIF-1α and ERCC1 and to elucidate the clinical significance of their expression in patients with small cell lung cancer (SCLC) treated with front-line platinum-based chemotherapy. METHODS: SCLC biopsy samples were obtained before front-line platinum-based chemotherapy from 111 patients with SCLC (limited disease, 29; extensive disease [ED], 82) between January 2002 and December 2009 at Gyeongsang National University Hospital. The expression levels of HIF-1α and ERCC1 were assessed by immunohistochemistry. RESULTS: High expression levels of ERCC1 and HIF-1α were observed in 49 (44.1%) and 71 (64.0%) of 111 patients, respectively. Expression of ERCC1 and HIF-1α was not significantly associated with age, sex, Eastern Cooperative Oncology Group performance status, weight loss, or response to treatment, regardless of stage. In ED-SCLC, low expression in the HIF-1α group showed statistically better survival compared with high expression in the HIF-1α group (p = 0.018). Multivariate analysis revealed that response to front-line platinum-based chemotherapy (p < 0.001), good Eastern Cooperative Oncology Group performance status (0-1) (p = 0.002), and low expression of HIF-1α (p = 0.004) were independent predictors of better overall survival in ED-SCLC. CONCLUSIONS: Low expression of HIF-1α may be a useful predictor of better overall survival in ED-SCLC patients treated with front-line platinum-based chemotherapy.

Suppression of mTOR via Akt-dependent and -independent mechanisms in selenium-treated colon cancer cells: involvement of AMPKalpha1.

Activation of the mammalian target of rapamycin (mTOR) pathway promotes tumorigenesis, and inhibiting the mammalian target of rapamycin complex 1 (mTORC1) has emerged as an attractive target for suppressing tumor growth. We found that selenium treatment of HT-29 colon cancer cells suppressed mTORC1 through Akt-independent and -dependent pathways. In Akt-independent mTORC1 inhibition in selenium-treated colon cancer cells, adenosine monophosphate-activated protein kinase (AMPK) alpha(1) was crucial for suppression of mTORC1 activity. In contrast, the Akt-dependent mTORC1 inhibition by selenium did not require AMPKalpha(1). The importance of the AMPKalpha(1)-mTORC1 pathway in mediating the antiproliferative action of selenium was examined in xenograft tumors, and the suppression of mTORC1 as well as Akt was concomitant with an increase in AMPKalpha(1) activity. These findings suggest that the antiproliferative effect of selenium is mediated by an Akt-independent AMPKalpha(1)/mTORC1 pathway or by the Akt/tuberous sclerosis complex 2 /mTORC1 pathway.

Is inactivation of O6-methylguanine DNA methyltransferase still a favorable prognostic factor of patients with diffuse large B-cell lymphoma in the era of R-CHOP chemotherapy?

The prognostic significance of O6-methylguanine DNA methyltransferase (MGMT) inactivation was evaluated in patients with diffuse large B-cell lymphoma (DLBCL) who received cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) in addition to rituximab. In this retrospective study, we used the methylation-specific polymerase chain reaction to investigate MGMT promoter methylation status and immunohistochemistry to evaluate MGMT expression in patients with DLBCL who received rituximab plus CHOP (R-CHOP) chemotherapy. No difference in patient characteristics, disease characteristics, response, or survival in patients with DLBCL who received front-line R-CHOP chemotherapy was observed according to MGMT methylation status and MGMT expression. On multivariate analysis, Grade 3-4 mucositis in the MGMT methylated group was significantly higher than that in the MGMT unmethylated group (hazard ratio (HR) 2.40, 95% CIs: 1.26-7.26, p = 0.014). This study demonstrated that inactivation of MGMT does not appear to play an important role in patients with DLBCL who received R-CHOP chemotherapy either with regard to the response rate or overall survival. Additionally, Grade 3-4 mucositis was found to be significantly related with inactivation of MGMT by a multivariate analysis.

Effect of microneedle on the pharmacokinetics of ketoprofen from its transdermal formulations.

Non-invasive transdermal delivery using microneedle arrays was recently introduced to deliver a variety of large and hydrophilic compounds into the skin, including proteins and DNA. In this study, a microneedle array was applied to the delivery of a hydrophobic drug, ketoprofen, to determine if transdermal delivery in rats can be improved without the need for permeation enhancers. The ability of a microneedle to increase the skin permeability of ketoprofen was tested using the following procedure. A microneedle array was inserted into the lower back skin of a rat using a clip for 10 min. Subsequently, 24 mg/kg of a ketoprofen gel was loaded on the same site where the microneedle had been applied. Simultaneously, the microneedle was coated with 24 mg/kg of a ketoprofen gel, and inserted into the skin using a clip for 10 min. As a negative control experiment, only 24 mg/kg of the ketoprofen gel was applied to the shaved lower back of a rat. Blood samples were taken at the indicated times. The plasma concentration (C(p)) was obtained as a function of time (t), and the pharmacokinetic parameters were calculated using the BE program. The group loaded with the microneedle coated with ketoprofen gel showed a 1.86-fold and 2.86-fold increase in the AUC and C((max)) compared with the ketoprofen gel alone group. These results suggest that a microneedle can be an ideal tool for transdermal delivery products.

Enhanced bioavailability of soy isoflavones by complexation with beta-cyclodextrin in rats.

In order to improve the solubility and bioavailability of a soy isoflavone extract (IFE), inclusion complexes (IFE-beta-CD) of the isoflavone extract with beta-cyclodextrin (beta-CD) were prepared and studied for their solubility and bioavailability. The aqueous solubility of the complexes of IFE with beta-CD (2.0 mg/ml) was about 26 times that of IFE itself (0.076 mg/ml). The same dosages of IFE and IFE-beta-CD were orally administered to SD rats (Sprague-Dawley) on an isoflavone glycoside (IFG) basis (daidzin, genistin and glycitin), and the plasma concentrations of daidzein, genistein and glycitein were measured over time to estimate the average AUC (area under the plasma concentration versus time curve) of the isoflavones. After the oral administration, the AUC values for daidzein, genistein and glycitein were 340, 11 and 28 microg x min/ml, respectively. In contrast, the respective AUC values after the administration of IFE-beta-CD were 430, 20 and 48 microg x min/ml. The bioavailability of daidzein in IFE-beta-CD was increased to 126% by the formation of inclusion complexes with beta-CD, compared with that in IFE. Furthermore, the bioavailability of genistein and glycitein in IFE-beta-CD formulation was significantly higher by up to 180% and 170%, respectively, compared with that of IFE p=0.008 and p=0.028, respectively). These results show that the absorption of IFE could be improved by the complexation of IFE with beta-CD (IFE-beta-CD).

Release behavior and photo-image of nifedipine tablet coated with high viscosity grade hydroxypropylmethylcellulose: effect of coating conditions.

An orally applicable nifedipine-loaded core tablets was coated using high viscosity grade HPMC (100,000 cps) in ethanol/water cosolvent. The release of coated tablet was evaluated using USP paddle method in 900 ml of simulated gastric fluid (pH 1.2) for 2 h followed by intestinal fluid (pH 6.8) for 10 h. The surface morphologies using scanning electron microscope and photo-images using digital camera of coated tablet during the release test were also visualized, respectively. The viscosity of hydro-alcoholic HPMC solution largely decreased as the amount of ethanol increased. There was no significant difference in viscosity among plasticizers used. The distinct and continuous coated layer was observed using scanning electron microscope. However, the surface morphologies were highly dependent on HPMC concentration and ratio of coating solvents. The higher ratio of ethanol/water gave a longer lag time prior to drug release. Lag time also increased as a function of the coating levels based on weight gains due to increased thickness of coated layer. Lag time is inversely correlated with HPMC concentration in ethanol/water (5:1) cosolvent. As the HPMC concentration slightly decreased from 3.8 to 3.2% in hydroalcoholic coating solution, a large increase of lag time was observed. As the swelling (mixing) time of high viscosity grade HPMC in ethanol/water cosolvent increased from 1 to 5 h, the release rate was decreased due to enough plasticization of polymer. Based on photo-imaging analysis, the coated tablet was initially swelled and gelled without erosion and disintegration over 5 h. The disintegration of the coated tablet was occurred approximately 7 h after dissolution, resulting in pulsed release of drug. The high viscosity grade HPMC can be applicable for polymeric coating after careful selection of solvent systems. The release behavior and lag time could be controlled by coating conditions such as HPMC concentration, ethanol/water ratio as a coating solvent, coating level and swelling (mixing) time of coating solution. The current time-controlled release tablet coated with high viscosity grade HPMC with a designated lag time followed by a rapid release may provide an alternative to site specific or colonic delivery of drugs. In addition, the release behavior can be matched with body's circadian rhythm pattern in chronotherapy.

Enhanced rectal bioavailability of ibuprofen in rats by poloxamer 188 and menthol.

To improve the bioavailability of poorly water-soluble ibuprofen in the rectum with poloxamer and menthol, the effects of menthol and poloxamer 188 on the aqueous solubility of ibuprofen were investigated. The dissolution and pharmacokinetic study of ibuprofen delivered by the poloxamer gels composed of poloxamer 188 and menthol were then performed. In the absence of poloxamer, the solubility of ibuprofen increased until the ratio of menthol to ibuprofen increased from 0:10 to 4:6 followed by an abrupt decrease in solubility above the ratio of 4:6, indicating that four parts menthol formed eutectic mixture with six parts ibuprofen. In the presence of poloxamer, the solutions with the same ratio of menthol to ibuprofen showed abrupt increase in the solubility of ibuprofen. The poloxamer gel with menthol/ibuprofen ratio of 1:9 and higher than 15% poloxamer 188 showed the maximum solubility of ibuprofen, 1.2mg/ml. Menthol improved the dissolution rates of ibuprofen from poloxamer gels. Release mechanism showed that the release rate of ibuprofen from the poloxamer gels without menthol was independent of the time but the drug might be released from the poloxamer gels with menthol by Fickian diffusion. Furthermore, the poloxamer gel with menthol (poloxamer/menthol/ibuprofen (15%/0.25%/2.5%)) gave significantly higher initial plasma concentrations, C(max) and AUC of ibuprofen than did solid suppository, indicating that the drug from poloxamer gel could be more absorbed than that from solid one in rats. Thus, the poloxamer gel with poloxamer 188 and menthol was a more effective rectal dosage form for ibuprofen.

Improved solubility and in vitro dissolution of Ibuprofen from poloxamer gel using eutectic mixture with menthol.

To improve the solubility and in vitro dissolution of poorly water-soluble ibuprofen with poloxamer and menthol, the effects of menthol and poloxamer 188 on the aqueous solubility of ibuprofen were investigated. The dissolution study of ibuprofen delivered by poloxamer gels composed of poloxamer 188 and menthol were performed. In the absence of poloxamer, the solubility of ibuprofen increased until the ratio of menthol to ibuprofen increased from 0:10 to 4:6, followed by an abrupt decrease in solubility above the ratio of 4:6, indicating that 4 parts of ibuprofen formed eutectic mixture with 6 parts of menthol. In the presence of poloxamer 188, the solutions with the same ratio of menthol to ibuprofen showed abrupt increase in the solubility of ibuprofen. Furthermore, the solution with ratio of 4:6 showed more than 2.5- and 6-fold increase in the solubility of ibuprofen compared with that without poloxamer and that without menthol, respectively. The poloxamer gel with menthol/ibuprofen ratio of 1:9 and higher than 15% poloxamer 188 showed the maximum solubility of ibuprofen, 1.2 mg/ml. Menthol improved the dissolution rates of ibuprofen from poloxamer gels. Dissolution mechanism showed that the dissolution rate of ibuprofen from the poloxamer gels without menthol was independent of the time, but the drug might be dissolved from the poloxamer gels with menthol by Fickian diffusion. Thus, the poloxamer gels developed using eutectic mixture with menthol, which gave the improved solubility and dissolution of drug, are potential candidates for ibuprofen-loaded transdermal and rectal delivery system.