Transdermal delivery of metoprolol by electroporation

Electroporation, i.e., the creation of transient "pores" in lipid membranes leading to increased permeability, could be used to promote transdermal drug delivery. We have evaluated metoprolol permeation through full thickness hairless rat skin in vitro following electroporation with an exponentially decaying pulse. Application of electric pulses increased metoprolol permeation as compared to diffusion through untreated skin. Raising the number of twin pulses (300 V, 3 ms; followed after 1 s by 100 V, 620 ms) from 1 to 20 increased drug transport. Single pulse (100 V, 620 ms) was as effective as twin pulse application (2200 V, 1100 V or 300 V, 3 ms; followed after 1 s by 100 V, 620 ms). In order to investigate the effect of pulse voltage on metoprolol permeation, 5 single pulses (each separated by 1 min) were applied at varying voltages from 24 to 450 V (pulse time 620 ms). A linear correlation between pulse voltage and cumulative metoprolol transported after 4 h suggested that voltage controls the quantity of drug delivered. Then, the effect of pulse time on metoprolol permeation was studied by varying pulse duration of 5 single 100 V pulses from 80 to 710 ms (each pulse also separated by 1 min). Cumulative metoprolol transported after 4 h increased linearly with the pulse time. Therefore, pulse time was also a control factor of the quantity of drug delivered but to a lesser extent than the voltage at least at 100 V.(ABSTRACT TRUNCATED AT 250 WORDS

Paclitaxel-loaded PEGylated PLGA-based nanoparticles: in vitro and in vivo evaluation

The incorporation efficiency of PTX was higher with the nanoprecipitation technique. The release behavior of PTX exhibited a biphasic pattern characterized by an initial burst release followed by a slower and continuous release. The in vitro anti-tumoral activity was assessed using the Human Cervix Carcinoma cells (HeLa) by the MTT test and was compared to the commercial formulation Taxol® and to Cremophor® EL. When exposed to 25 µg/ml of PTX, the cell viability was lower for PTX-loaded nanoparticles than for Taxol® (IC50 5.5 vs 15.5 µg/ml). Flow cytometry studies showed that the cellular uptake of PTX-loaded nanoparticles was concentration and time dependent. Exposure of HeLa cells to Taxol® and PTX-loaded nanoparticles induced the same percentage of apoptotic cells. PTX-loaded nanoparticles showed greater tumor growth inhibition effect in vivo on TLT tumor, compared with Taxol®. Therefore, PTX-loaded nanoparticles may be considered as an effective anticancer drug delivery system for cancer chemotherapy

Transdermal alniditan delivery by skin electroporation.

The aim of this study was to evaluate the transdermal permeation of alniditan by electroporation and to compare with iontophoretic delivery. The influence of the electrical parameters of electroporation was investigated in vitro using a factorial design study. The transdermal flux of alniditan was enhanced by two orders of magnitude by application of high voltage electrical pulses. The electrical parameters of electroporation-i.e. the voltage, the duration and the number of pulses-allowed a control of drug permeation. Both transport during and after pulsing were shown to be important for alniditan transdermal delivery by electroporation. Electroporation was found more efficient in promoting alniditan permeation than an iontophoresis transferring the same amount of charges

Novel self-assembling PEG-p-(CL-co-TMC) polymeric micelles as safe and effective delivery system for Paclitaxel.

Paclitaxel (PTX) is an effective anti-cancer drug currently used to treat a wide variety of cancers. Unfortunately, to nonaqueous vehicle containing Cremophor((R)) EL is associated with serious clinical side effects. This work aimed to evaluate the ability of polymeric micelles to (i) solubilize PTX without Cremophor((R)) EL and to be used as a (ii) safe and (iii) effective delivery system for PTX. Hence, we developed novel self-assembling poly(ethyleneglycol)(750)-block-poly(epsilon-caprolactone-co-trimethylenecarbonate) (PEG-p-(CL-co-TMC)) polymeric micelles which form micelles spontaneously in aqueous solution. The solubility of PTX increased up to three orders of magnitude. The PTX-loaded micelles showed a slow release of PTX with no burst effect. The HeLa cells viability assessed by the MTT test was lower for PTX-loaded micelles than for Taxol((R)) (IC(50) 10.6 vs. 17.6mug/ml). When solubilized in micelles, PTX induced apoptosis comparable with Taxol((R)). The maximum tolerated doses (MTD) of PTX-loaded micelles and Taxol((R)) in mice were 80mg/kg and 13.5mg/kg, respectively, after intraperitoneal administration; and 45mg/kg and 13.5mg/kg, respectively, after intravenous administration. Similar anti-tumor efficacy of PTX-loaded micelles and Taxol((R)) was observed at the dose of 13.5mg/kg on TLT-tumor-bearing mice, while the body weight loss was only observed in Taxol((R)) group. However, as higher dose was tolerated (80mg/kg - IP), a higher growth delay was induced with PTX-loaded micelles. These results demonstrated that PTX-loaded self-assembling micelles present a similar anti-tumor efficacy as Taxol((R)), but significantly reduced the toxicity allowing the increase in the dose until 80mg/kg for better therapeutic response

Improvement of the decision efficiency of the accuracy profile by means of a desirability function for analytical methods validation - Application to a diacetyl-monoxime colorimetric assay used for the determination of urea in transdermal iontophoretic extracts

Validation of analytical methods is a widely used and regulated step for each analytical method. However, the classical approaches to demonstrate the ability to quantify of a method do not necessarily fulfill this objective. For this reason an innovative methodology was recently introduced by using the tolerance interval and accuracy profile, which guarantee that a pre-defined proportion of future measurements obtained with the method will be included within the acceptance limits. Accuracy profile is an effective decision tool to assess the validity of analytical methods. The methodology to build such a profile is detailed here. However, as for any visual tool it has a part of subjectivity. It was then necessary to make the decision process objective in order to quantify the degree of adequacy of an accuracy profile and to allow a thorough comparison between such profiles. To achieve this, we developed a global desirability index based on the three most important validation criteria: the trueness, the precision and the range. The global index allows the classification of the different accuracy profiles obtained according to their respective response functions. A diacetyl-monoxime colorimetric assay for the determination of urea in transdermal iontophoretic extracts was used to illustrate these improvements

Targeting of tumor endothelium by RGD-grafted PLGA-nanoparticles loaded with Paclitaxel

Paclitaxel (PTX)-loaded PEGylated PLGA-based nanoparticles (NP) have been previously described as more effective in vitro and in vivo than Taxol®. The aim of this study was to test the hypothesis that our PEGylated PLGA-based nanoparticles grafted with the RGD peptide or RGD-peptidomimetic (RGDp) would target the tumor endothelium and would further enhance the anti-tumor efficacy of PTX. The ligands were grafted on the PEG chain of PCL-b-PEG included in the nanoparticles. We observed in vitro that RGD-grafted nanoparticles were more associated to Human Umbilical Vein Endothelial cells (HUVEC) by binding to αvβ3 integrin than non-targeted nanoparticles. Doxorubicin was also used to confirm the findings observed for PTX. In vivo, we demonstrated the targeting of RGD and RGDp-grafted nanoparticles to tumor vessels as well as the effective retardation of TLT tumor growth and prolonged survival times of mice treated by PTX-loaded RGD-nanoparticles when compared to non-targeted nanoparticles. Hence, the targeting of anti-cancer drug to tumor endothelium by RGD-labeled NP is a promising approach