Transport of therapeutics across intestinal epithelium

This chapter focuses on the oral administration of therapeutics. Patients prefer oral administration because it is painless and simple to implement. [...

New lipid nanocapsules for decitabine encapsulation

Introduction: Currently decitabine, an antimetabolite agent is approved for acute myeloid leukemia in old patients and is administered via intra-venous (IV) route. It is a harsh treatment characterized by side effects mainly related with the IV administration as pain, risk of infectious, nursing and hospitalization. Oral route may represent a valid alternative route to IV administration because patient convenience and compliance. Due to the quick hydrolyze of the molecule in acidic conditions, decitabine oral bioavailability is very low, it ranges from 3.9 to 14%. The objective of this work was to design and develop a novel formulation to administer the decitabine per os. Material and method: Firstly, decitabine was solubilized in a reverse micelle (RM) formulation based on a mixture of Transcutol® HP and Tween® 80. RM were then incorporated into lipid nanocapsules (LNC-RM) (1).The formulation was then freeze dried and the stability after the freeze drying process was evaluated by comparing the size, the polydispersity index and the zeta potential to the initial values obtained before the freeze drying. The drug paylaod and encapsulation efficiency were determined after an ultracentrifugation to collect the free decitabine and the decitabine loaded in LNC-RM in two different fractions. In vitro release behavior of decitabine from LNC-RM in PBS medium (pH 7.4, 37°C) was evaluated using a dialysis method (Float a Lyzer 100kDa) and compared with the free drug solution. The drug was quantified using LC-MS/MS method. Finally, in vitro permeability study of decitabine-loaded LNC-RM was assessed in a Caco-2 cell model (2). Results and discussion: After freeze drying LNC-RM were stables showing an average size of around 30nm, with a low polydispersity index and a neutral zeta potential. The decitabine payload was 216±57µg/mL, with an encapsulation efficiency of 45±8%. The in vitro release results showed that, after 90min, almost 5% of decitabine was released from the LNC-RM, while the 45% was released from decitabine solution. The apparent permeability was increased when decitabine is encapsulated as compared to the free drug solution in the Caco-2 model after a contact of four hours. Conclusion: Here we presented a new formulation for the oral administration of decitabine. Further studies will be developed to assed the stability of the system in simulated gastro-intestinal media. References: (1) Heurtault B., et al. Pharm Research. 19(6), 2002 (2) Roger E., et al. Eur J Pharm Biopharm. 79(1), 201

Development and characterization of a novel lipid nanocapsule formulation of Sn38 for oral administration

The purpose of this work was to encapsulate 7-Ethyl-10-hydroxy-camptothecin (Sn38) in lipid nanocapsules (LNCs) using phase inversion-based method in order to deliver Sn38 by oral route. LNCs were prepared by a low-energy emulsification method and were characterized for size, polydispersity index (PDI), surface charge, drug payload, in vitro drug release, and storage stability. Moreover, in view of an oral administration, in vitro stability in gastrointestinal fluid and permeability across Caco-2 cells were tested. Sn38-loaded LNCs with a mean particle size of 38+/-2nm were obtained. The particles displayed a narrow size distribution and a drug payload of 0.40+/-0.07mg/g of LNC dispersion. In vitro stability in simulated gastric and intestinal media was also observed. Finally, Sn38-loaded LNCs improved permeability of Sn38 across Caco-2 cells (5.69+/-0.87x10(6)cms(-1) at 6h vs 0.31+/-0.02x10(6)cms(-1)) and intracellular concentration compared with free Sn38. In conclusion, Sn38 nanocarriers have been developed and display a strong potential for oral administration

Decitabine encapsulation in nanovector to improve acute myeloid leukemia treatment

Acute myeloid leukemia (AML) mainly affects adult patients, and for older ones unfit for intensive chemotherapy only few therapies are available. Hypomethylating agents, as decitabine, is a labeled option but its plasma half-life is short whereas a long cell exposure time improves response rate. Only intravenous administration is available, whereas an oral route is generally preferred by patients. Consequently, to enhance plasma half-life and to develop an oral decitabine formulation, in this work decitabine was encapsulated in nanoparticles. Two different strategies were tested: decitabine loaded into lipid nanocapsules (DAC-LNC), and a decitabine-prodrug synthesis [3’(OH)-5’(OH)-(lauroyl)2-modified DAC] encapsulated into LNC (DAC-(C12)2-LNC). DAC-LNC and DAC-(C12)2-LNC particles were obtained with sizes of 26.5 ± 0.5 nm and 27.45 ± 0.05 nm respectively, and drug payloads of 0.47 ± 0.06 mg/mL and 5.8 ± 0.5 mg/mL (corresponding to 2.3 ± 0.2 mg/mL of decitabine). Both formulations were able to increase in vitro human plasma half-life by protecting decitabine from degradations. Compared to free-decitabine solutions, both nanoparticle formulations were able to preserve decitabine cytotoxicity on an AML cell line (HEL). Moreover, permeability studies across an adenocarcinoma cell model (Caco-2 cells) demonstrated that DAC-LNC improve decitabine’s intestinal permeability whereas DAC-(C12)2-LNC decreased it. However, this drawback could be countered by the enhanced decitabine’s stability in gastrointestinal fluids thanks to DAC-(C12)2-LNC, leading to more available drug for absorption. Globally, both formulation have demonstrated their ability to improve DAC plasma half-life in vitro and their potential for oral administration. In vivo pharmacokinetics evaluations may now confirm interests of such strategies

Nanocapsules lipidiques, procédé de préparation et utilisation comme médicament

The present invention relates to nanocapsules, including: a core essentially consisting of a fatty substance, which is liquid or semi-liquid at ambient temperature, and including a hydrophobic active principle and a diethylene glycol ether; an outer lipid shell which is solid at ambient temperature. The lipid nanocapsules of the invention are intended in particular for the manufacture of a drug

Development of decitabine nano objects for oral administration

Introduction: Currently decitabine (trade name Dacogen®) is only approved for acute myeloid leukemia in old patients and is administered via intra-venous (IV) route once a day for five days, every four weeks. It’s a painful treatment with difficulties due to IV administration: pain, risk of infectious, nursing, hospitalization. Decitabine oral bioavailability is limited to 3.9 to 14% mainly due to the quick hydrolyse of the molecule in acidic conditions. The aim of our study was to design new formulations to administer decitabine orally. Material and methods: Four different nano-object strategies, already published, have been adapted for decitabine encapsulation: lipid nanocapsules (LNC) with a Transcutol® HP core (1), lipid drug conjugate (LDC) (2), polymeric nanoparticles (NP) (3), and LNC loaded with reverse micelles (LNC-RM) (4). For each strategy, size, polydispersity index (PdI), and Zeta potential were monitored by dynamic light scattering on a Zetasizer® Nano series DTS 1060. Encapsulation efficiency and encapsulation yield were determined after an ultra-centrifugation of the formulation or by filtration associated to centrifugation depending on the nanoparticles formulated. An UPLC-UV method was developed to quantify decitabine. Results and discussion: Very different sizes of nanoparticles were obtained: 27.4±1.6 nm for LNC-RM, 38.7±7.0 nm for LNC, 34.3±4.5 nm for LDC and 145.2±0.9 for NP. PdI were found inferior to 0.2 for all the encapsulation strategies used. Encapsulation efficiency was not sufficient for LNC, LDC and NP (1.20±2.00%, 25.00±1.94% and 2.81±3.10% respectively) but promising for the LNC-RM (48.76±14.18%), corresponding to an encapsulation yield of 244.6±74.9μg/mL. Conclusion: All formulations were prepared with only GRAS excipients and without class 1 and 2 solvents. Analytical method were designed and validated in accordance with the international conference on harmonization. An interesting formulation based on LNC and reverse micelle were obtained. The stability of this formulation in simulated fluids and in vitro permeability across a caco-2 cells culture model are in progress. References: (1) Heurtault B., Saulnier P., Pech B., Proust J-E., B J-P. Pharmaceutical Research. 19(6), 875-880, 2002 (2) Neupane Y-R., Sabir M-D., Ahmad N., Ali M., Kohli K. Nanotechnology. 24, 1-11, 2013 (3) Gonzalo T., Lollo G., Garcia-Fuentes M., Torres D., Correa J., Riguera R., Fernandez-Megia E., Calvo P., Avilés P, Guillén M-J., Alonso M-J., Journal of Controlled Release. 169, 10–16, 2013 (4) Vrignaud S, Anton N, Gayet P, Benoit J-P., Saulnier P. European journal of pharmaceutics and biopharmaceutics. 79, 197-204, 201

The gastrointestinal stability of lipid nanocapsules

The in vitro gastrointestinal stability of lipid nanocapsules (LNCs) was studied in different media. The size of LNCs was determined in simulated gastric and intestinal media. In updated fasted state simulated intestinal fluid (FaSSIF-V2) and updated fed state simulated intestinal fluid (FeSSIF-V2) media, the encapsulation ratio of paclitaxel-loaded LNCs was also measured. The size of LNCs was not modified after 3h in simulated gastric fluid and simulated intestinal fluid described by the United States Pharmacopeia, in FaSSIF, FaSSIF-V2, and in FeSSIF. Moreover, in the presence of pancreatin in FeSSIF-V2, a decreased above 30% of the loading of paclitaxel was observed. This was attributed to the presence of lipase in pancreatin that could interact with Lipoid (a mixture of phosphatidylcholine and phosphatidylethanolamine), present on the shell of LNC. As a conclusion, LNCs were stable on gastric medium and fasted state intestinal medium

Lipid nanocarriers improve paclitaxel transport throughout human intestinal epithelial cells by using vesicle-mediated transcytosis

The use of lipid nanocapsules (LNCs) has enabled an improvement of the oral bioavailability of paclitaxel (Ptx). However, mechanisms that support this recent observation are not yet understood. By focusing on the well defined in vitro Caco-2 model, the purpose of this study was to evaluate the transport of LNCs across a model intestinal barrier. Firstly, four sizes of paclitaxel or dye (Nile Red)-loaded LNCs were formulated and LNCs with sizes between 26.3+/-2.7nm and 132.7+/-5.5nm were obtained. Different transport and uptake experiments were then performed across a Caco-2 cells culture model using these LNCs. Paclitaxel-loaded LNCs improved permeability of Ptx across intestinal epithelium compared with free Ptx or Taxol((R)) by a factor of 3.5. At 37 degrees C particle size did not influence transport efficiency. However, at 4 degrees C a decrease in Ptx transport was observed with increasing size of LNCs. Thus, with LNCs of 25nm size, the apparent permeability coefficient (P(app)) was 5.3+/-1.1cm s(-1) at 37 degrees C and 2.2+/-0.4cm s(-1) at 4 degrees C. In comparison in LNCs of 130nm size, the P(app) decreased from 5.8+/-0.8cm s(-1) at 37 degrees C to 0.5+/-0.1cm s(-1) at 4 degrees C. The uptake of LNCs by Caco-2 cells and the incapacity of LNCs to open tight junctions were also demonstrated. Furthermore, experiment transports were performed in the presence of different inhibitors of endocytosis. Findings indicated a reduction of Ptx transport of 30+/-6% when cell cholesterol was depleted, 65+/-12% when caveolae-mediated endocytosis was inhibited and 20+/-8% when clathrin-mediated endocytosis was inhibited. Finally, transmission electronic microscopy showed the presence of nano-objects on the basolateral side of the Caco-2 cell monolayers when LNCs were applied on the apical side