Oral Delivery of Liraglutide-Loaded Zein/Eudragit-Chitosan Nanoparticles Provides Pharmacokinetic and Glycemic Outcomes Comparable to Its Subcutaneous Injection in Rats.

Liraglutide (LIRA) is a glucagon-like peptide-1 (GLP-1) receptor agonist renowned for its efficacy in treating type 2 diabetes mellitus (T2DM) and is typically administered via subcutaneous injections. Oral delivery, although more desirable for being painless and potentially enhancing patient adherence, is challenged by the peptide's low bioavailability and vulnerability to digestive enzymes. This study aimed to develop LIRA-containing zein-based nanoparticles stabilized with eudragit RS100 and chitosan for oral use (Z-ERS-CS/LIRA). These nanoparticles demonstrated a spherical shape, with a mean diameter of 238.6 nm, a polydispersity index of 0.099, a zeta potential of +40.9 mV, and an encapsulation efficiency of 41%. In vitro release studies indicated a prolonged release, with up to 61% of LIRA released over 24 h. Notably, the nanoparticles showed considerable resistance and stability in simulated gastric and intestinal fluids, suggesting protection from pH and enzymatic degradation. Pharmacokinetic analysis revealed that orally administered Z-ERS-CS/LIRA paralleled the pharmacokinetic profile seen with subcutaneously delivered LIRA. Furthermore, in vivo tests on a diabetic rat model showed that Z-ERS-CS/LIRA significantly controlled glucose levels, comparable to the results observed with free LIRA. The findings underscore Z-ERS-CS/LIRA nanoparticles as a promising approach for oral LIRA delivery in T2DM management.

Dual strategy to improve the oral bioavailability of efavirenz employing nanomicelles and curcumin as a bio-enhancer.

The present investigation was focused on the development of Soluplus®-based nanomicelles (NMs) (10 % w/v) loaded with Efavirenz (EFV) (5 mg/mL) and Curcumin (natural bio-enhancer) (CUR) (5, 10 and 15 mg/mL) to improve the oral bioavalability of EFV. Micellar formulations were obtained employing an acetone-diffusion technique. Apparent aqueous solubility was increased up to ∼1250-fold and 25,000-fold for EFV and CUR, respectively. Drug-loaded nanoformulations showed an excellent colloidal stability with unimodal size distribution and PDI values < 0.30. In vitro drug release was 41.5 % (EFV) and 2.6 % (CUR) from EFV-CUR-NMs over 6 h in simulated gastrointestinal fluids. EFV-CUR-loaded NMs resulted as safe nanoformulations according to the in vitro cytocompatibility assays in Caco-2 cells. Furthermore, CUR bio-enhancer activity was demonstrated for those nanoformulations. A CUR concentration of 15 mg/mL produced a significant (p < 0.05) increment (2.64-fold) of relative EFV oral bioavailability. Finally, the active role of the lymphatic system in the absorption process of EFV, after its oral administration was assessed in a comparative pharmacokinetic study in presence and absence of cycloheximide, a lymphatic transport inhibitor. Overall our EFV-CUR-NMs denoted their potential as a novel nanotechnological platform, representing a step towards an optimized "nano-sized" therapy for AIDS patients.

In-situ formation of nanoparticles from drug-loaded 3D polymeric matrices.

The in-situ formation of nanoparticles from polymer-based solid medicines, although previously described, has been overlooked despite its potential to interfere with oral drug bioavailability. Such polymeric pharmaceuticals are becoming increasingly common on the market and can become even more popular due to the dizzying advance of 3D printing medicines. Hence, this work aimed to study this phenomenon during the dissolution of 3D printed tablets produced with three different polymers, hydroxypropylmethylcellulose acetate succinate (HPMCAS), polyvinyl alcohol (PVA), and Eudragit RL PO® (EUD RL) combined with plasticizers and the model drug naringenin (NAR). The components' interaction, dissolution behavior, and characteristics of the formed particles were investigated employing thermal, spectroscopic, mechanical, and chromatographic assays. All the systems generated stable spherical-shaped particles throughout 24 h, encapsulating over 25% of NAR. Results suggest encapsulation efficiencies variations may depend on interactions between polymer-drug, drug-plasticizer, and polymer-plasticizer, which formed stable nanoparticles even in the drug absence, as observed with the HPMCAS and EUD RL formulations. Additionally, components solubility in the medium and previous formulation treatments are also a decisive factor for nanoparticle formation. In particular, the treatment provided by hot-melt extrusion and FDM 3D printing affected the dissolution efficiency enhancing the interaction between the components, reverberating on particle size and particle formation kinetics mainly for HPMCAS and EUD RL. In conclusion, the 3D printing process influences the in-situ formation of nanoparticles, which can directly affect oral drug bioavailability and needs to be monitored.

Chloroquinolone Carboxamide Derivatives as New Anti-HSV-1 Promising Drugs.

BACKGROUND: Since the emergence of HSV resistant strains, new antiviral agents have emerged and still are urgently needed, especially those with alternative targets. OBJECTIVE: In this work, we evaluated new quinolone derivatives as anti-HSV. METHODS: For this study, cells were infected and treated with different components to evaluate the profile of HSV replication in vitro. In addition, studies were performed to determine the pharmacokinetic toxicity and profile of the compound. RESULTS: Indeed the EC50 values of these promising molecules ranged between 8 µM and 32 µM. We have also showed that all compounds inhibited the expression of ICP27 viral proteins, which gives new insights in the search for new target for antiherpetic therapy. Chlorine in positions C6 and phosphonate in position C1 have shown to be important for viral inhibition. The chloroquinolone carboxamide derivatives fulfilled "Lipinsky Rule of Five" for good oral bioavailability and showed higher intestinal absorption and blood brain barrier penetration, as well as lower toxicity profile. CONCLUSION: Although the inhibition activities of chloroquinolone carboxamide derivatives were lower than acyclovir, they showed different modes of action in comparison to the drugs currently available. These findings encourage us to continue pre-clinical studies for the development of new anti-HSV-1 agents.

Effect of particle size on the oral absorption of isoliquiritigenin nanocrystals

Abstract As one of the most promising formulations for poorly water-soluble drugs, nanocrystals have been attracting increasing attention in recent years. Isoliquiritigenin (ISL) is a flavonoid with a chalcone structure, and possesses many biological activities. However, its clinical application is significantly limited mainly due to its low oral bioavailability caused by poor hydrophilicity. To address this, ISL nanocrystals were developed in this study to improve its oral bioavailability. Three types of nanocrystals with differing particle size; R1, R2, and R3, were prepared by anti- solvent precipitation or anti-solvent precipitation combined with sonication, which was optimized by single-factor experiments. These nanocrystals were characterized based on their physical properties, in vitro release, and in vivo absorption performance. The mean particle size of R1, R2, and R3 was 555.7, 271.0, and 46.2, respectively. The dissolution ratio of ISL in the nanocrystals was significantly improved, with the quickest rate recorded in R2. Peak concentration and area under the concentration-time curve of R2 after oral administration in rats was 5.83- and 2.72-fold higher than that of the ISL solution, respectively. These findings indicate that the dissolution and absorption of ISL can be significantly enhanced by nanocrystals, and the dissolution behavior and pharmacokinetic properties of nanocrystals is significantly influenced by particle size.

Molecular design aided by random forests and synthesis of potent trypanocidal agents as cruzain inhibitors for Chagas disease treatment.

Cruzain is an established target for the identification of novel trypanocidal agents, but how good are in vitro/in vivo correlations? This work describes the development of a random forests model for the prediction of the bioavailability of cruzain inhibitors that are Trypanosoma cruzi killers. Some common properties that characterize drug-likeness are poorly represented in many established cruzain inhibitors. This correlates with the evidence that many high-affinity cruzain inhibitors are not trypanocidal agents against T. cruzi. On the other hand, T. cruzi killers that present typical drug-like characteristics are likely to show better trypanocidal action than those without such features. The random forests model was not outperformed by other machine learning methods (such as artificial neural networks and support vector machines), and it was validated with the synthesis of two new trypanocidal agents. Specifically, we report a new lead compound, Neq0565, which was tested on T. cruzi Tulahuen (ß-galactosidase) with a pEC50 of 4.9. It is inactive in the host cell line showing a selectivity index (SI = EC50cyto /EC50T. cruzi ) higher than 50.

Corrigendum: A Nanostructured Lipid System to Improve the Oral Bioavailability of Ruthenium(II) Complexes for the Treatment of Infections Caused by Mycobacterium tuberculosis.

[This corrects the article DOI: 10.3389/fmicb.2018.02930.].

Corrigendum: A Nanostructured Lipid System to Improve the Oral Bioavailability of Ruthenium(II) Complexes for the Treatment of Infections Caused by Mycobacterium tuberculosis.

[This corrects the article DOI: 10.3389/fmicb.2018.02930.].

A Nanostructured Lipid System to Improve the Oral Bioavailability of Ruthenium(II) Complexes for the Treatment of Infections Caused by Mycobacterium tuberculosis.

Tuberculosis (TB) is an infectious, airborne disease caused by the bacterium Mycobacterium tuberculosis that mainly affects the lungs. Fortunately, tuberculosis is a curable disease, and in recent years, death rates for this disease have decreased. However, the existence of antibiotic-resistant strains and the occurrence of co-infections with human immunodeficiency virus (HIV), have led to increased mortality in recent years. Another area of concern is that one-third of the world's population is currently infected with M. tuberculosis in its latent state, serving as a potential reservoir for active TB. In an effort to address the failure of current TB drugs, greater attention is being given to the importance of bioinorganic chemistry as an ally in new research into the development of anti-TB drugs. Ruthenium (Ru) is a chemical element that can mimic iron (Fe) in the body. In previous studies involving the following heteroleptic Ru complexes, [Ru(pic)(dppb)(bipy)]PF6 (SCAR1), [Ru(pic)(dppb)(Me-bipy)]PF6 (SCAR2), [Ru(pic)(dppb)(phen)]PF6 (SCAR4), cis-[Ru(pic)(dppe)2]PF6 (SCAR5), and [Ru(pic)(dppe)(phen)]PF6 (SCAR7), we observed excellent anti-TB activity, moderate cell-toxicity, and a lack of oral bioavailability in an in vivo model of these complexes. Therefore, the objective of this study was to evaluate the toxicity and oral bioavailability of these complexes by loading them into a nanostructured lipid system. The nanostructured lipid system was generated using different ratios of surfactant (soybean phosphatidylcholine, Eumulgin®, and sodium oleate), aqueous phase (phosphate buffer with a concentration of 1X and pH 7.4), and oil (cholesterol) to generate a system for the incorporation of Ru(II) compounds. The anti-TB activity of the compounds was determined using a microdilution assay with Resazurin (REMA) against strains of M. tuberculosis H37Rv and clinical isolates resistant. Cytotoxicity assay using J774.A1 cells (ATCC TIB-67) and intra-macrophage activity were performed. The oral bioavailability assay was used to analyze blood collected from female BALB/C mice. Plasma collected from the same mice was analyzed via inductively coupled plasma mass spectrometry (ICP-MS) to quantify the number of Ru ions. The complexes loaded into the nanostructured lipid system maintained in vitro activity and toxicity was found to be reduced compared with the compounds that were not loaded. The complexes showed intra-macrophagic activity and were orally bioavailable.

Computational modeling of human oral bioavailability: what will be next?

INTRODUCTION: The oral route is the most convenient way of administrating drugs. Therefore, accurate determination of oral bioavailability is paramount during drug discovery and development. Quantitative structure-property relationship (QSPR), rule-of-thumb (RoT) and physiologically based-pharmacokinetic (PBPK) approaches are promising alternatives to the early oral bioavailability prediction. Areas covered: The authors give insight into the factors affecting bioavailability, the fundamental theoretical framework and the practical aspects of computational methods for predicting this property. They also give their perspectives on future computational models for estimating oral bioavailability. Expert opinion: Oral bioavailability is a multi-factorial pharmacokinetic property with its accurate prediction challenging. For RoT and QSPR modeling, the reliability of datasets, the significance of molecular descriptor families and the diversity of chemometric tools used are important factors that define model predictability and interpretability. Likewise, for PBPK modeling the integrity of the pharmacokinetic data, the number of input parameters, the complexity of statistical analysis and the software packages used are relevant factors in bioavailability prediction. Although these approaches have been utilized independently, the tendency to use hybrid QSPR-PBPK approaches together with the exploration of ensemble and deep-learning systems for QSPR modeling of oral bioavailability has opened new avenues for development promising tools for oral bioavailability prediction.

Novel Zinc(II) Complexes [Zn(atc-Et)2] and [Zn(atc-Ph)2]: In Vitro and in Vivo Antiproliferative Studies.

Cisplatin and its derivatives are the main metallodrugs used in cancer therapy. However, low selectivity, toxicity and drug resistance are associated with their use. The zinc(II) (Zn(II)) thiosemicarbazone complexes [Zn(atc-Et)2] (1) and [Zn(atc-Ph)2] (2) (atc-R: monovalent anion of 2-acetylpyridine N4-R-thiosemicarbazone) were synthesized and fully characterized in the solid state and in solution via elemental analysis, Fourier transform infrared (FTIR), ultraviolet-visible (UV-Vis) and proton nuclear magnetic resonance (¹H NMR) spectroscopy, conductometry and single-crystal X-ray diffraction. The cytotoxicity of these complexes was evaluated in the HepG2, HeLa, MDA-MB-231, K-562, DU 145 and MRC-5 cancer cell lines. The strongest antiproliferative results were observed in MDA-MB-231 and HepG2 cells, in which these complexes displayed significant selective toxicity (3.1 and 3.6, respectively) compared with their effects on normal MRC-5 cells. In vivo studies were performed using an alternative model (Artemia salina L.) to assure the safety of these complexes, and the results were confirmed using a conventional model (BALB/c mice). Finally, tests of oral bioavailability showed maximum plasma concentrations of 3029.50 µg/L and 1191.95 µg/L for complexes 1 and 2, respectively. According to all obtained results, both compounds could be considered as prospective antiproliferative agents that warrant further research.

Functionalized Polymers for Enhance Oral Bioavailability of Sensitive Molecules.

Currently, many sensitive molecules have been studied for effective oral administration. These substances are biologically active compounds that mainly suffer early degradation in the gastrointestinal tract (GIT) and physicochemical instability, inactivation and poor solubility and permeability. The sensibility of the biomolecules has limited their oral administration in the body and today is an important research topic to achieve desired effects in medicine field. Under this perspective, various enhancement approaches have been studied as alternatives to increase their oral bioavailability. Some of these strategies include functionalized polymers to provide specific useful benefits as protection to the intestinal tract by preventing its degradation by stomach enzymes, to increase their absorption, permeability, stability, and to make a proper release in the GIT. Due to specific chemical groups, shapes and sizes, morphologies, mechanical properties, and degradation, recent advances in functionalized polymers have opened the door to great possibilities to improve the physicochemical characteristics of these biopharmaceuticals. Today, many biomolecules are found in basic studies, preclinical steps, and others are late stage clinical development. This review summarizes the contribution of functionalized polymers to enhance oral bioavailability of sensitive molecules and their application status in medicine for different diseases. Future trends of these polymers and their possible uses to achieve different formulation goals for oral delivery are also covered in this manuscript.

Atorvastatin calcium loaded chitosan nanoparticles: in vitro evaluation and in vivo pharmacokinetic studies in rabbits / Atorvastatina de cálcio carregadas nanopartículas de quitosana: avaliação farmacocinética in vitro e in vivo em estudos de coelhos

In this study, we prepared atorvastatin calcium (AVST) loaded chitosan nanoparticles to improve the oral bioavailability of the drug. Nanoparticles were prepared by solvent evaporation technique and evaluated for its particle size, entrapment efficiency, zeta potential, in vitro release and surface morphology by scanning electron microscopy (SEM). In addition, the pharmacokinetics of AVST from the optimized formulation (FT5) was compared with marketed immediate release formulation (Atorva^(r)) in rabbits. Particle size of prepared nanoparticles was ranged between 179.3 ± 7.12 to 256.8 ± 8.24 nm with a low polydispersity index (PI) value. Zeta potential study showed that the particles are stable with positive values between 13.03 ± 0.32 to 46.90 ± 0.49 mV. FT-IR studies confirmed the absence of incompatibility of AVST with excipient used in the formulations. In vitro release study showed that the drug release was sustained for 48 h. Results of pharmacokinetics study showed significant changes in the pharmacokinetic parameter (2.2 fold increase in AUC) of the optimized formulation as compared to marketed formulation (Atorva^(r)). Thus, the developed nanoparticles evidenced the improvement of oral bioavailability of AVST in rabbit model...

No presente estudo, preparamos nanopartículas de quitosana com atorvastatina cálcica (AVST) para melhorar a biodisponibilidade oral do fármaco. As nanopartículas foram preparadas pela técnica de evaporação de solvente, avaliando-se a granulometria, a eficiência de encapsulamento, o potencial zeta, a liberação in vitroe a morfologia da superfície, por meio da microscopia eletrônica de varredura (MEV). Além disso, a farmacocinética da formulação otimizada de AVST (FT5) foi comparada com a formulação comercial, de liberação imediata, comercializada (Atorva(r)), em coelhos. O tamanho das das nanopartículas variou na faixa de 179,3 a 256,8 ± 7,12 ± 8,24 nm, com baixo índice polidispersibilidade (PI). O estudo do potencial Zeta mostrou que as partículas são estáveis, com valores positivos entre 13,03 ± 0,32 a 46,90 ± 0,49 mV. Os estudos de FT-IR confirmaram a ausência de incompatibilidade de AVST com o excipiente utilizado nas formulações. O estudo de liberação in vitro mostrou que liberação sustentada do fármaco por 48 horas. Os resultados do estudo farmacocinético mostraram alterações significativas nos parâmetros (aumento de 2,2 vezes na ASC) da formulação otimizada em relação à comercializada (Atorva(r) ). Assim, o desenvolvimento de nanopartículas evidenciou a melhora da biodisponibilidade oral de AVST em coelhos...

Novel protease inhibitor-loaded Nanoparticle-in-Microparticle Delivery System leads to a dramatic improvement of the oral pharmacokinetics in dogs.

With the advent of the Highly Active Antiretroviral Therapy, the morbidity and the mortality associated to HIV have been considerably reduced. However, 35-40 million people bear the infection worldwide. One of the main causes of therapeutic failure is the frequent administration of several antiretrovirals that results in low patient compliance and treatment cessation. In this work, we have developed an innovative Nanoparticle-in-Microparticle Delivery System (NiMDS) comprised of pure drug nanocrystals of the potent protease inhibitor indinavir free base (used as poorly water-soluble model protease inhibitor) produced by nanoprecipitation that were encapsulated within mucoadhesive polymeric microparticles. Pure drug nanoparticles and microparticles were thoroughly characterized by diverse complementary techniques. NiMDSs displayed an encapsulation efficiency of approximately 100% and a drug loading capacity of up to 43% w/w. In addition, mucoadhesiveness assays ex vivo conducted with bovine gut showed that film-coated microparticles were retained for more than 6 h. Finally, pharmacokinetics studies in mongrel dogs showed a dramatic 47- and 95-fold increase of the drug oral bioavailability and half-life, respectively, with respect to the free unprocessed drug. These results support the outstanding performance of this platform to reduce the dose and the frequency of administration of protease inhibitors, a crucial step to overcome the current patient-incompliant therapy.

Spray-dried didanosine-loaded polymeric particles for enhanced oral bioavailability.

Didanosine (ddI) is a water-soluble antiretroviral used in the treatment of HIV that undergoes fast gastric degradation to an inactive hypoxanthine. Therefore, its oral bioavailability is relatively low (20-40%). In this work, we investigated for the first time a scalable open-loop spray-drying method with co-current flow for the encapsulation of ddI (model drug) within particles of the biocompatible polyester poly(epsilon-caprolactone). The average diameter of the particles was 36-118 µm and the morphology spherical. The encapsulation efficiency ranged from 60% to 100% with yields of up to 65%. ATR/FT-IR analysis indicated that most of the drug was encapsulated within the particles. In vitro release assays showed that the particles released the drug within 120 min. Finally, oral administration to rats led to a statistically significant 2.5-fold increase of the bioavailability with respect to a ddI aqueous solution, highlighting the potential of this technology to encapsulate efficiently other hydrophilic antiretrovirals and, by doing so, to overcome different biopharmaceutical drawbacks associated with the oral administration.

Oral effectiveness of PMIC4, a novel hydroxyethylpiperazine analogue, in Leishmania amazonensis.

Pentavalent antimonials have saved the lives of thousands of Leishmania-infected patients more than seventy years but, unfortunately, they are highly toxic and require parenteral delivery. Therefore, the search for safer and orally delivered alternative is a need. This paper describes the antileishmanial properties of PMIC4, a novel hydroxyethylpiperazine analogue. PMIC4 showed potent activity against intracellular amastigotes of Leishmania amazonensis, with IC50 of 1.8 µM and selectivity index higher than 100-fold, calculated in relation to the toxicity on the host cell. Following laboratory animal welfare policies, we analyzed the absorption, distribution, metabolism, excretion and toxicity (ADMET) properties and calculated the Lipinski's rule of five of PMIC4 before proceeding to in vivo tests. PMIC4 satisfied Lipinski's rule of five and presented high probability of human intestinal absorption, suggesting a good chance of druglikeness and oral bioavailability. For in vivo studies, PMIC4 was administered via intralesional injection (3.4 mg/kg/day, three times a week) or orally (34.0 mg/kg/day, five times a week) to L. amazonensis-infected BALB/c mice throughout the 98 day experiments. At the end of the treatment period, serum markers of toxicity were measured. When administered orally, PMIC4 controlled the lesions in L. amazonensis-infected BALB/c mice without altering serological markers of toxicity. These results demonstrate that PMIC4 is a promising molecular scaffold, orally effective against experimental leishmaniasis.

Novel nelfinavir mesylate loaded d-α-tocopheryl polyethylene glycol 1000 succinate micelles for enhanced pediatric anti HIV therapy: In vitro characterization and in vivo evaluation.

Worldwide more than 35 million people are living with Human Immunodeficiency Virus (HIV) where 3.3 million are children. This translates in approximately 700 new daily infections in children only in 2012. Prolonged High Activity Antiretroviral Therapy (HAART) regimes could present low-patient compliance, especially in children, affecting therapeutic success. Nelfinavir mesylate (NFV) is a non-peptidic HIV-1 protease inhibitor (IP) which was the first IP recommended for pediatric use (>2 years-old). It exhibits pH-dependant aqueous solubility which results highly restricted at physiological pH values. The former represents a main clinical limitation due to the reduction on drug absorption along the small intestine after an oral administration, leading to unpredictable drug bioavailability. Moreover a liquid formulation of NFV is not available worldwide, preventing appropriate dose adjustment and more convenient administration. In this framework, the present investigation reports the development of a NFV highly concentrated aqueous formulation for a more appropriate management of pediatric anti-HIV therapy. The aim was to encapsulate NFV within D-α-tocopheryl polyethylene glycol 1000 succinate micelles to improve its aqueous solubility and its oral pharmacokinetic parameters. Results show that NFV aqueous solubility was increased up to 80.3 mg/mL. NFV-loaded micelles exhibited a hydrodynamic diameter of 5.6 nm and a spherical morphology as determined by dynamic light scattering and transmission electronic microscopy, respectively. In vitro NFV release profile demonstrated a cumulative drug release of 56% at 6 h. Finally, in vivo data showed a significant (p<0.01) increase of Area-Under-the-Curve between 0 and 24 h for NFV encapsulated in micelles in comparison with a NFV suspension prepared with glycerin 20% v/v and carboxymethylcellulose sodium 0.5% w/v, representing an increment on drug oral relative bioavailability of 1.71-fold. Thereby, this formulation represents an innovative nanotechnological platform to improve pediatric HIV pharmacotherapy.