Preformulation study for the selection of a suitable polymer for the development of ellagic acid-based solid dispersion using hot-melt extrusion.

Ellagic acid is one of the most studied polyphenolic compounds due to its numerous promising therapeutic properties. However, this therapeutic potential remains difficult to exploit owing to its low solubility and low permeability, resulting in low oral bioavailability. In order to allow an effective therapeutic application of EA, it is therefore necessary to develop strategies that sufficiently enhance its solubility, dissolution rate and bioavailability. For this purpose, solid dispersions based on pre-selected polymers such as Eudragit® EPO, Soluplus® and Kollidon® VA 64, with 5% w/w ellagic acid loading were prepared by hot extrusion and characterized by X-ray diffraction, FTIR spectroscopy and in vitro dissolution tests in order to select the most suitable polymer for future investigations. The results showed that Eudragit® EPO was the most promising polymer for ellagic acid solid dispersions development because its extrudates allowed to obtain a solution supersaturated in ellagic acid that was stable for at least 90 min. Moreover, the resulting apparent solubility was 20 times higher than the actual solubility of ellagic acid. The extrudates also showed a high dissolution rate of ellagic acid (96.25% in 15 min), compared to the corresponding physical mixture (6.52% in 15 min) or the pure drug (1.56% in 15 min). Furthermore, increasing the loading rate of ellagic acid up to 12% in extrudates based on this polymer did not negatively influence its release profile through dissolution tests.

Effect of PEG Anchor and Serum on Lipid Nanoparticles: Development of a Nanoparticles Tracking Method.

Polyethylene glycol (PEG) is used in Lipid Nanoparticles (LNPs) formulations to confer stealth properties and is traditionally anchored in membranes by a lipid moiety whose length significantly impacts the LNPs fate in vivo. C18 acyl chains are efficiently anchored in the membrane, while shorter C14 lipids are quickly desorbed and replaced by a protein corona responsible for the completely different fate of LNPs. In this context, a method to predict the biological behavior of LNPs depending on the lipid-PEG dissociation was developed using the Nanoparticle Tracking Analysis (NTA) method in serum. Two formulations of siRNA-containing LNPs were prepared including CSL3 or SM-102 lipids and were grafted with different lipids-PEG (C18, C14 lipids-PEG, and Ceramide-PEG). The impact of the lipid-PEG on the interactions between LNPs and serum components was demonstrated by monitoring the mean particle size and the concentration over time. In vitro, these formulations demonstrated low toxicity and efficient gene knockdown on tumor MDA-MB-231 cells, but serum was found to significantly impact the efficiency of C18-PEG-based LNPs, while it did not impact the efficiency of C14-PEG-based LNPs. The NTA method demonstrated the ability to discriminate between the behaviors of LNPs according to serum proteins' interactions. CSL3 lipid and Cer-PEG were confirmed to have promise for LNP formulation.

Fused deposition modeling 3D printing of solid oral dosage forms containing amorphous solid dispersions: How to elucidate drug dissolution mechanisms through surface spectral analysis techniques?

Many active principles belong to the second class of the Biopharmaceutics Classification System due to their low aqueous solubility. Elaboration of new solid oral forms by hot-melt extrusion and fused deposition modeling appears as a promising tool to increase the dissolution rate of these drugs. Indeed, hot-melt extrusion allows the amorphisation of drugs and forms with complex geometries are built by 3D printing. Therefore, the goal of this work is to enhance the dissolution rate of poorly soluble drugs using hot-melt extrusion coupled with fused deposition modeling. Four formulations containing Affinisol® 15LV, Kollidon® VA64 and a challenging amount of itraconazole (25 % (wt.)) were successfully printed into forms of 20, 50 and 80 % infill densities. Differential scanning calorimetry analysis has shown that itraconazole remained amorphous during 52 weeks. The drug release rate was highly improved compared to itraconazole in a crystalline form. The dissolution rate was influenced by the infill density and the polymer composition of printed forms which could modify respectively the surface to volume ratio and the distribution of the components in the printed forms. One formulation printed with 20 % infill density even had a solubility profile similar to that of Sporanox®, the commercialized drug product in Belgium.

Innovative lipoplexes formulations with enhanced siRNA efficacy for cancer treatment: Where are we now?

Over the past two decades, RNA interference has become an extensively studied mechanism to silence gene and treat diseases including cancer. siRNA appears as a promising strategy that could avoid some side effects related to traditional chemotherapy. Considering the weak stability of naked siRNA in blood, vectors like cationic liposomes or Lipid Nanoparticles (LNPs) are widely used to carry and protect siRNA until it reaches the tumor targeted. Despite extensive research, only three RNAi drugs are currently approved by the Food and Drug Administration, including only one LNP formulation of siRNA to treat hereditary ATTR amyloidosis. This shows the difficulty of lipoplexes clinical translation, in particular in cancer therapy. To overcome the lipoplexes limitations, searches are made on innovative lipoplexes formulations with enhanced siRNA efficacy. The present review is focusing on the recent use of pH-sensitive lipids, peptides and cell-penetrating peptides or polymers. The incorporation of some of these components in the lipoplex formulation induces a fusogenic property or an enhanced endosomal escape, an enhanced cellular uptake, an enhanced tumor targeting, an improved stability in the blood stream …These innovations appear critical to obtain an efficient siRNA accumulation in tumor cells with effective antitumor effect considering the complex tumor environment.

Physical formulation approaches for improving aqueous solubility and bioavailability of ellagic acid: A review.

Ellagic acid (EA) is a polyphenolic active compound with antimalarial and other promising therapeutic activities. However, its solubility and its permeability are both low (BCS IV). These properties greatly compromise its oral bioavailability and clinical utilizations. To overcome these limitations of the physicochemical parameters, several formulation approaches, including particle size reduction, amorphization and lipid-based formulations, have been used. Although these strategies have not yet led to a clinical application, some of them have resulted in significant improvements in the solubility and bioavailability of EA. This critical review reports and analyses the different formulation approaches used by scientists to improve both the biopharmaceutical properties and the clinical use of EA.

The Budesonide-Hydroxypropyl-ß-Cyclodextrin Complex Attenuates ROS Generation, IL-8 Release and Cell Death Induced by Oxidant and Inflammatory Stress. Study on A549 and A-THP-1 Cells.

Synthetic glucocorticoids such as budesonide (BUD) are potent anti-inflammatory drugs commonly used to treat patients suffering from chronic inflammatory diseases. A previous animal study reported a higher anti-inflammatory activity with a 2-hydroxypropyl-ß-cyclodextrin (HPßCD)-based formulation of BUD (BUD:HPßCD). This study investigated, on cellular models (A549 and A-THP-1), the effect of BUD:HPßD in comparison with BUD and HPßCD on the effects induced by oxidative and inflammatory stress as well as the role of cholesterol. We demonstrated the protective effect afforded by BUD:HPßCD against cytotoxicity and ROS generation induced by oxidative and inflammatory stress. The effect observed for BUD:HPßCD was comparable to that observed with HPßCD with no major effect of cholesterol content. We also demonstrated (i) the involvement of the canonical molecular pathway including ROS generation, a decrease in PI3K/Akt activation, and decrease in phosphorylated/unphosphorylated HDAC2 in the effect induced by BUD:HPßCD, (ii) the maintenance of IL-8 decrease with BUD:HPßCD, and (iii) the absence of improvement in glucocorticoid insensitivity with BUD:HPßCD in comparison with BUD, in conditions where HDAC2 was inhibited. Resulting from HPßCD antioxidant and anticytotoxic potential and protective capacity against ROS-induced PI3K/Akt signaling and HDAC2 inhibition, BUD:HPßCD might be more beneficial than BUD alone in a context of concomitant oxidative and inflammatory stress.

Cannabidiol aqueous solubility enhancement: Comparison of three amorphous formulations strategies using different type of polymers.

Poor aqueous solubility of terpenophenolic compound Cannabidiol (CBD) is a major issue in the widespread use of this promising therapeutic polyphenol. Moreover, choosing the appropriate strategy to overcome this challenge is time-consuming and based on trial-error processes. The amorphous form of CBD provided higher aqueous solubility as well as faster dissolution rate in comparison with crystalline CBD. Nevertheless, amorphous forms of CBD tend to recrystallize. The aim of this study was to use three different strategies based on the stabilization of the amorphous form. Cyclodextrins (CH3αCD, HPßCD and HPγCD.), mesoporous silicas (Silsol® and Syloid® AL-1FP) and water soluble polymers (Kollidon® VA64, Kollidon® 12PF and Soluplus®) were processed by using the following techniques: freeze-drying, spray-drying, subcritical carbon dioxide impregnation or hot-melt extrusion. All the obtained formulations provided complete amorphous CBD, although the drug loading depend highly of the excipients. CBD-cyclodextrin formulations, processed by freeze-drying or spray-drying, and CBD-mesoporous silica formulations, processed by subcritical CO2 or by atmospheric impregnation, provided significant increase of aqueous solubility. While the use of Kollidon® 12PF did not provided significant increased solubility within 90 min, Kollidon® VA64 has been highlighted as the excipient that exhibits the highest increase of aqueous solubility of this study. Finally, all formulations, excepted CBD-ALFP formulations, showed adequate stability within at least two months.

Liposomes and drug-in-cyclodextrin-in-liposomes formulations encapsulating 17ß-estradiol: An innovative drug delivery system that prevents the activation of the membrane-initiated steroid signaling (MISS) of estrogen receptor α.

The encapsulation into liposomes of several types of molecules presents the advantages to protect the activity of these molecules and to target specific tissues. Nevertheless, a major obstacle remains the incomplete understanding of nano-bio interactions. Specifically, the impact that inclusion of drug into liposomes or of drug-in-cyclodextrin-in liposomes (DCL) could have on the molecular and cellular mechanism of drug action is largely unknown. As a proof of concept, we evaluated the impact of 17ß-estradiol (E2) included into liposomes or DCL on estrogen receptor (ER)α signaling pathways. Indeed, ERα relays the pleiotropic actions of E2 in physiology and pathophysiology through two major pathways: (1) the genomic/nuclear effects associated to the transcriptional activity of the ERα and (2) the rapid/nongenomic/membrane-initiated steroid signaling (MISS) effects related to the induction of fast signaling pathways occurring when ERα is anchored to the plasma membrane. We evidenced that the inclusion of E2 into liposomes (Lipo-E2) or into DCL (DCL-E2) prevented the activation of the rapid/nongenomic/extranuclear/MISS pathway of ERα, while the activation of the genomic/nuclear pathway was maintained. These results support that Lipo-E2 and DCL-E2 could be a useful tool to delineate the complex molecular mechanisms associated to ERα. In conclusion, this study supports the notion that inclusion of drugs into liposomes or DCL could modify some specific pathways of their molecular and cellular mechanisms of action. These results emphasized that attention should be paid to nano-bio interactions induced by the use of nanovectors in medicine.

Ozone-primed neutrophils promote early steps of tumour cell metastasis to lungs by enhancing their NET production.

BACKGROUND: Air pollution, including particulates and gazes such as ozone (O3), is detrimental for patient's health and has repeatedly been correlated to increased morbidity and mortality in industrialised countries. Although studies have described a link between ambient particulate matter and increased lung cancer morbidity, no direct relation has yet been established between O3 exposure and metastatic dissemination to lungs. OBJECTIVES: To outline the mechanisms through which pulmonary O3 exposure modulates metastasis kinetics in an experimental mouse model of O3 exposure. METHODS: Metastatic responses to pulmonary O3 exposure were assessed using a reliable experimental mouse model of concomitant pulmonary O3 exposure and tumour cell injection. Roles of neutrophils in O3-induced lung metastasis were highlighted using blocking anti-Ly6G antibodies; moreover, the implication of neutrophil extracellular traps (NETs) in metastatic processes was evaluated using MRP8cre-Pad4lox/lox mice or by treating mice with DNase I. RESULTS: Pulmonary O3 exposure strongly facilitates the establishment of lung metastasis by (1) Inducing a pulmonary injury and neutrophilic inflammation, (2) Influencing very early steps of metastasis, (3) Priming neutrophils' phenotype to release NETs that favour tumour cell colonisation in lungs. The ability of O3-primed neutrophils to enhance lung colonisation by tumour cells was proven after their adoptive transfer in Balb/c mice unexposed to O3. CONCLUSIONS: Pulmonary neutrophils induced by O3 promote metastatic dissemination to lungs by producing NETs. These findings open new perspectives to improve treatment and prevention strategies in patients affected by metastatic diseases.

Safety and tolerance of cidofovir as a 2% gel for local application in high-grade cervical intraepithelial neoplasia: A phase 1 investigation.

OBJECTIVES: The primary objective was to evaluate the safety and local tolerance of a topical 2% (w/w) cidofovir gel, applied directly to the cervices of women with high-grade cervical intraepithelial neoplasia (CIN 2+). The secondary objective was to evaluate the pharmacokinetics of cidofovir during the treatment. MATERIALS AND METHODS: Nine women with CIN 2+, were treated with a course of 3 g of cidofovir gel, applied locally once per week for 3 weeks in total (9 g). The treatment was administered in a cervical cap, applied to the cervix for 5 or 10 hours (n = 6 and 3 patients, respectively). Follow-up included a structured questionnaire, a gynecological examination, blood analysis for hematology, C-reactive protein (CRP), and renal function assessment plus pharmacokinetic analyses of cidofovir after each treatment and at the end of the full course. RESULTS: No clinically significant hematological/biochemical abnormalities or serious adverse events (SAE) were reported, although 6 mild to moderate adverse events (AE) occurred in relation to the study drug: 1 flu-like syndrome and 5 local AEs. Plasma concentrations of cidofovir were very low (mean Cmax of 103.0 and 99.2 ng/mL after 5 and 10 hours of exposure, respectively). CONCLUSION: Cidofovir, directly applied on CIN 2+, is reasonably well tolerated and the systemic exposure following topical application is much lower than that seen with intravenous administration, at the approved dose.
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Changes in membrane biophysical properties induced by the Budesonide/Hydroxypropyl-ß-cyclodextrin complex.

Budesonide (BUD), a poorly soluble anti-inflammatory drug, is used to treat patients suffering from asthma and COPD (Chronic Obstructive Pulmonary Disease). Hydroxypropyl-ß-cyclodextrin (HPßCD), a biocompatible cyclodextrin known to interact with cholesterol, is used as a drug-solubilizing agent in pharmaceutical formulations. Budesonide administered as an inclusion complex within HPßCD (BUD:HPßCD) required a quarter of the nominal dose of the suspension formulation and significantly reduced neutrophil-induced inflammation in a COPD mouse model exceeding the effect of each molecule administered individually. This suggests the role of lipid domains enriched in cholesterol for inflammatory signaling activation. In this context, we investigated the effect of BUD:HPßCD on the biophysical properties of membrane lipids. On cellular models (A549, lung epithelial cells), BUD:HPßCD extracted cholesterol similarly to HPßCD. On large unilamellar vesicles (LUVs), by using the fluorescent probes diphenylhexatriene (DPH) and calcein, we demonstrated an increase in membrane fluidity and permeability induced by BUD:HPßCD in vesicles containing cholesterol. On giant unilamellar vesicles (GUVs) and lipid monolayers, BUD:HPßCD induced the disruption of cholesterol-enriched raft-like liquid ordered domains as well as changes in lipid packing and lipid desorption from the cholesterol monolayers, respectively. Except for membrane fluidity, all these effects were enhanced when HPßCD was complexed with budesonide as compared with HPßCD. Since cholesterol-enriched domains have been linked to membrane signaling including pathways involved in inflammation processes, we hypothesized the effects of BUD:HPßCD could be partly mediated by changes in the biophysical properties of cholesterol-enriched domains.

Development and evaluation of injectable nanosized drug delivery systems for apigenin.

The purpose of this study was to develop different injectable nanosized drug delivery systems (NDDSs) i.e. liposome, lipid nanocapsule (LNC) and polymeric nanocapsule (PNC) encapsulating apigenin (AG) and compare their characteristics to identify the nanovector(s) that can deliver the largest quantity of AG while being biocompatible. Two liposomes with different surface characteristics (cationic and anionic), a LNC and a PNC were prepared. A novel tocopherol modified poly(ethylene glycol)-b-polyphosphate block-copolymer was used for the first time for the PNC preparation. The NDDSs were compared by their physicochemical characteristics, AG release, storage stability, stability in serum, complement consumption and toxicity against a human macrovascular endothelial cell line (EAhy926). The diameter and surface charge of the NDDSs were comparable with previously reported injectable nanocarriers. The NDDSs showed good encapsulation efficiency and drug loading. Moreover, the NDDSs were stable during storage and in fetal bovine serum for extended periods, showed low complement consumption and were non-toxic to EAhy926 cells up to high concentrations. Therefore, they can be considered as potential injectable nanocarriers of AG. Due to less pronounced burst effect and extended release characteristics, the nanocapsules could be favorable approaches for achieving prolonged pharmacological activity of AG using injectable NDDS.

Promoting Vaginal Distribution of E7 and MCL-1 siRNA-Silencing Nanoparticles for Cervical Cancer Treatment.

There is an urgent need to develop a less aggressive and more effective treatment against cervical lesions induced by different high-risk human papillomavirus (HR-HPV). We investigated the potential of a cocktail of small interfering RNA (siRNA) directed against the oncoprotein E6 (E6), the oncoprotein E7 (E7), or the antiapoptotic protein MCL-1 (MCL-1). The combination of siRNA anti-E7 and anti-MCL-1 demonstrated high efficacy on multiple HPV16 and HPV18 cell lines and no effects on healthy keratinocytes. This gene therapy has been considered for a vaginal administration since this route of application holds high potential for the treatment of diseases in the female reproductive tracts. Therefore, PEGylated lipoplexes have been designed and characterized to protect siRNA and to diffuse in the mucosal environment before they reach the cervico/vaginal epithelium. This new nanovector complexed to the combination of active siRNA induced an efficient mRNA knockdown since biological effects were obtained in vitro. This work also provided evidence that the PEGylated lipoplexes had appropriate physicochemical properties to diffuse into a mucin network according to size measurement experiments in artificial mucus. After demonstrating the distribution and the efficacy of siRNA into a 3D-cervical model lesion and through porcine vaginal mucosa, in vivo experiments in mouse have been performed under physiological conditions. This study revealed a complete and sustained coverage of the mucosal epithelium following an unique vaginal administration of fluorescent PEGylated lipoplexes. Overall, our results showed the potential of the PEGylated lipoplexes for the prolonged delivery of active siRNA to treat HPV-induced lesions.

PEGylated and Functionalized Aliphatic Polycarbonate Polyplex Nanoparticles for Intravenous Administration of HDAC5 siRNA in Cancer Therapy.

Guanidine and morpholine functionalized aliphatic polycarbonate polymers are able to deliver efficiently histone deacetylase 5 (HDAC5) siRNA into the cytoplasm of cancer cells in vitro leading to a decrease of cell proliferation were previously developed. To allow these biodegradable and biocompatible polyplex nanoparticles to overcome the extracellular barriers and be effective in vivo after an intravenous injection, polyethylene glycol chains (PEG750 or PEG2000) were grafted on the polymer structure. These nanoparticles showed an average size of about 150 nm and a slightly positive ζ-potential with complete siRNA complexation. Behavior of PEGylated and non-PEGylated polyplexes were investigated in the presence of serum, in terms of siRNA complexation (fluorescence correlation spectroscopy), size (dynamic light scattering and single-particle tracking), interaction with proteins (isothermal titration calorimetry) and cellular uptake. Surprisingly, both PEGylated and non-PEGylated formulations presented relatively good behavior in the presence of fetal bovine serum (FBS). Hemocompatibility tests showed no effect of these polyplexes on hemolysis and coagulation. In vivo biodistribution in mice was performed and showed a better siRNA accumulation at the tumor site for PEGylated polyplexes. However, cellular uptake in protein-rich conditions showed that PEGylated polyplex lost their ability to interact with biological membranes and enter into cells, showing the importance to perform in vitro investigations in physiological conditions closed to in vivo situation. In vitro, the efficiency of PEGylated nanoparticles decreases compared to non-PEGylated particles, leading to the loss of the antiproliferative effect on cancer cells.

Continuous production of itraconazole-based solid dispersions by hot melt extrusion: Preformulation, optimization and design space determination.

The purpose of this work was to increase the solubility and the dissolution rate of itraconazole, which was chosen as the model drug, by obtaining an amorphous solid dispersion by hot melt extrusion. Therefore, an initial preformulation study was conducted using differential scanning calorimetry, thermogravimetric analysis and Hansen's solubility parameters in order to find polymers which would have the ability to form amorphous solid dispersions with itraconazole. Afterwards, the four polymers namely Kollidon® VA64, Kollidon® 12PF, Affinisol® HPMC and Soluplus®, that met the set criteria were used in hot melt extrusion along with 25wt.% of itraconazole. Differential scanning confirmed that all four polymers were able to amorphize itraconazole. A stability study was then conducted in order to see which polymer would keep itraconazole amorphous as long as possible. Soluplus® was chosen and, the formulation was fine-tuned by adding some excipients (AcDiSol®, sodium bicarbonate and poloxamer) during the hot melt extrusion process in order to increase the release rate of itraconazole. In parallel, the range limits of the hot melt extrusion process parameters were determined. A design of experiment was performed within the previously defined ranges in order to optimize simultaneously the formulation and the process parameters. The optimal formulation was the one containing 2.5wt.% of AcDiSol® produced at 155°C and 100rpm. When tested with a biphasic dissolution test, more than 80% of itraconazole was released in the organic phase after 8h. Moreover, this formulation showed the desired thermoformability value. From these results, the design space around the optimum was determined. It corresponds to the limits within which the process would give the optimized product. It was observed that a temperature between 155 and 170°C allowed a high flexibility on the screw speed, from about 75 to 130rpm.

PEGylation of lipoplexes: The right balance between cytotoxicity and siRNA effectiveness.

The delivery of small interfering RNA (siRNA) is an attractive therapeutic approach to treat several pathologies, such as viral infections or cancers. However, the stability and the efficacy of these biotherapies are still a major obstacle to their use. Cationic liposomes (DOTAP/Chol/DOPE 1/0.75/0.5M ratio) have been complexed to siRNA (lipoplexes) in order to be administrated by the vaginal route, in the context of HPV16 induced cervical preneoplastic lesions. To overcome the constraint of the cervico-vaginal mucus, PEGylation is required to allow the diffusion of lipoplexes through it. Thereby, PEGylated lipoplexes coated with three types of polyethylene glycol (PEG) as DSPE-PEG2000, DSPE-PEG750 or C8-PEG2000-Ceramide (Ceramide-PEG2000) at different densities have been developed and characterized. PEGylated lipoplexes were successfully prepared and showed a hydrodynamic diameter around 200nm, appropriate for vaginal application. In vitro assays on HPV16 positive cell lines revealed that a positive charge of PEGylated lipoplexes allows a higher mRNA knockdown by siRNA. However, the cationic property is also associated to cytotoxicity. The addition of a high percentage of PEG prevented this toxicity but seemed also to reduce siRNA endosomal escape, probably by steric hindrance. The decreasing of PEG density of Ceramide-PEG2000 to 20% allows the release of siRNA and in consequence, biological activities, contrarily to DSPE-PEG. These results suggest that Ceramide-PEG is more appropriate for siRNA delivery compared to DSPE-PEG. In conclusion, the right balance between cytotoxicity and siRNA effectiveness has been found with the transfection of lipoplexes coated with 20% of Ceramide-PEG2000. This new nanovector could have a high potential against multiple mucosal diseases, such as human papillomavirus-induced genital lesions.

Capillary electrophoresis method to determine siRNA complexation with cationic liposomes.

Small interfering RNA (siRNA) inducing gene silencing has great potential to treat many human diseases. To ensure effective siRNA delivery, it must be complexed with an appropriate vector, generally nanoparticles. The nanoparticulate complex requires an optimal physiochemical characterization and the complexation efficiency has to be precisely determined. The methods usually used to measure complexation in gel electrophoresis and RiboGreen® fluorescence-based assay. However, those approaches are not automated and present some drawbacks such as the low throughput and the use of carcinogenic reagents. The aim of this study is to develop a new simple and fast method to accurately quantify the complexation efficiency. In this study, capillary electrophoresis (CE) was used to determine the siRNA complexation with cationic liposomes. The short-end injection mode applied enabled siRNA detection in less than 5 min. Moreover, the CE technique offers many advantages compared with the other classical methods. It is automated, does not require sample preparation and expensive reagents. Moreover, no mutagenic risk is associated with the CE approach since no carcinogenic product is used. Finally, this methodology can also be extended for the characterization of other types of nanoparticles encapsulating siRNA, such as cationic polymeric nanoparticles.

Nanocarriers for the treatment of glioblastoma multiforme: Current state-of-the-art.

Glioblastoma multiforme, a grade IV glioma, is the most frequently occurring and invasive primary tumor of the central nervous system, which causes about 4% of cancer-associated-deaths, making it one of the most fatal cancers. With present treatments, using state-of-the-art technologies, the median survival is about 14 months and 2 year survival rate is merely 3-5%. Hence, novel therapeutic approaches are urgently necessary. However, most drug molecules are not able to cross the blood-brain barrier, which is one of the major difficulties in glioblastoma treatment. This review describes the features of blood-brain barrier, and its anatomical changes with different stages of tumor growth. Moreover, various strategies to improve brain drug delivery i.e. tight junction opening, chemical modification of the drug, efflux transporter inhibition, convection-enhanced delivery, craniotomy-based drug delivery and drug delivery nanosystems are discussed. Nanocarriers are one of the highly potential drug transport systems that have gained huge research focus over the last few decades for site specific drug delivery, including drug delivery to the brain. Properly designed nanocolloids are capable to cross the blood-brain barrier and specifically deliver the drug in the brain tumor tissue. They can carry both hydrophilic and hydrophobic drugs, protect them from degradation, release the drug for sustained period, significantly improve the plasma circulation half-life and reduce toxic effects. Among various nanocarriers, liposomes, polymeric nanoparticles and lipid nanocapsules are the most widely studied, and are discussed in this review. For each type of nanocarrier, a general discussion describing their composition, characteristics, types and various uses is followed by their specific application to glioblastoma treatment. Moreover, some of the main challenges regarding toxicity and standardized evaluation techniques are narrated in brief.

Optimization of a PGSS (particles from gas saturated solutions) process for a fenofibrate lipid-based solid dispersion formulation.

The aim of this study was to develop a formulation containing fenofibrate and Gelucire(®) 50/13 (Gattefossé, France) in order to improve the oral bioavailability of the drug. Particles from gas saturated solutions (PGSS) process was chosen for investigation as a manufacturing process for producing a solid dispersion. The PGSS process was optimized according to the in vitro drug dissolution profile obtained using a biphasic dissolution test. Using a design of experiments approach, the effects of nine experimental parameters were investigated using a PGSS apparatus provided by Separex(®) (Champigneulles, France). Within the chosen experimental conditions, the screening results showed that the drug loading level, the autoclave temperature and pressure, the connection temperature and the nozzle diameter had a significant influence on the dissolution profile of fenofibrate. During the optimization step, the three most relevant parameters were optimized using a central composite design, while other factors remained fixed. In this way, we were able to identify the optimal production conditions that would deliver the highest level of fenofibrate in the organic phase at the end of the dissolution test. The closeness between the measured and the predicted optimal dissolution profiles in the organic phase demonstrated the validity of the statistical analyses.