Effect of particle size on oral bioavailability of darunavir-loaded solid lipid nanoparticles

Vitamin D loaded into lipid nanoparticles shows insulinotropic effect in INS-1E cells

Increasing evidence suggests a beneficial role of vitamin D (VitD) supplementation in addressing the widespread VitD deficiency, but currently used VitD3 formulations present low bioavailability and toxicity constrains. Hence, poly(L-lactide-co-glycolide) (PLGA) nanoparticles (NPs), solid-lipid nanoparticles (SLNs) and nanostructured lipid carriers (NLCs) were investigated to circumvent these issues. PLGA NPs prepared by emulsification or nanoprecipitation presented 74 or 200 nm, and association efficiency (AE) of 68 % and 17 %, respectively, and a rapid burst release of VitD3. Both SLN and NLCs presented higher polydispersity and larger NPs size, around 500 nm, which could be reduced to around 200 nm by use of hot high-pressure homogenization in the case of NLCs. VitD3 was efficiently loaded in both SLNs and NLCs with an AE of 82 and 99 %, respectively. While SLNs showed burst release, NLCs allowed a sustained release of VitD3 for nearly one month. Furthermore, NLCs showed high stability with maintenance of VitD3 loading for up to one month at 4 °C and no cytotoxic effects on INS-1E cells up to 72 h. A trending increase (around 30 %) on glucose-dependent insulin secretion was observed by INS-1E cells pre-treated with VitD3. This effect was consistently observed in the free form and after loading on NLCs. Overall, this work contributed to further elucidation on a suitable delivery system for VitD3 and on the effects of this metabolite on β cell function.

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.

Nanodelivery of Dietary Polyphenols for Therapeutic Applications

Advancement in nanotechnology has unleashed the therapeutic potentials of dietary polyphenols by enhancing bioavailability, improving biological half-life, and allowing site-specific drug delivery. In this review, through citation of relevant literature reports, we discuss the application of nano-pharmaceutical formulations, such as solid lipid nanoparticles, nano-emulsions, nano-crystals, nano-polymersomes, liposomes, ethosomes, phytosomes, and invasomes for dietary polyphenols. Following this, we highlight important studies concerning different combinations of nano formulations with dietary polyphenols (also known as nanophytopolyphenols). We also provide nano-formulation paradigms for enhancing the physicochemical properties of dietary polyphenols. Finally, we highlight the latest patents that were granted on nano-formulations of dietary polyphenols. Based on our review, we observe that nanosized delivery of herbal constituents, spices, and dietary supplements have the ability to improve biological processes and address issues connected with herbal treatments.

Chitosan-Hyaluronic Acid Nanoparticles for Active Targeting in Cancer Therapy

Cancer is the most common cause of death worldwide; therefore, there is a need to discover novel treatment modalities to combat it. One of the cancer treatments is nanoparticle technology. Currently, nanoparticles have been modified to have desirable pharmacological effects by using chemical ligands that bind with their specific receptors on the surface of malignant cells. Chemical grafting of chitosan nanoparticles with hyaluronic acid as a targeted ligand can become an attractive alternative for active targeting. Hence, these nanoparticles can control drug release with pH- responsive stimuli, and high selectivity of hyaluronic acid to CD44 receptors makes these nanoparticles accumulate more inside cells that overexpress these receptors (cancer cells). In this context, we discuss the benefits and recent findings of developing and utilizing chitosan–hyaluronic acid nanoparticles against distinct forms of cancer malignancy. From here we know that chitosan–hyaluronic acid nanoparticles (CHA-Np) can produce a nanoparticle system with good characteristics, effectiveness, and a good active targeting on various types of cancer cells. Therefore, this system is a good candidate for targeted drug delivery for cancer therapy, anticipating that CHA-Np could be further developed for various cancer therapy applications.

Luminescent PLGA Nanoparticles for Delivery of Darunavir to the Brain and Inhibition of Matrix Metalloproteinase-9, a Relevant Therapeutic Target of HIV-Associated Neurological Disorders

Human immunodeficiency virus (HIV) can independently replicate in the central nervous system (CNS) causing neurocognitive impairment even in subjects with suppressed plasma viral load. The antiretroviral drug darunavir (DRV) has been approved for therapy of HIV-infected patients, but its efficacy in the treatment of HIV-associated neurological disorders (HAND) is limited due to the low penetration through the blood–brain barrier (BBB). Therefore, innovations in DRV formulations, based on its encapsulation in optically traceable nanoparticles (NPs), may improve its transport through the BBB, providing, at the same time, optical monitoring of drug delivery within the CNS. The aim of this study was to synthesize biodegradable polymeric NPs loaded with DRV and luminescent, nontoxic carbon dots (C-Dots) and investigate their ability to permeate through an artificial BBB and to inhibit in vitro matrix metalloproteinase-9 (MMP-9) that represents a factor responsible for the development of HIV-related neurological disorders. Biodegradable poly(lactic-co-glycolic) acid (PLGA)-based nanoformulations resulted characterized by an average hydrodynamic size less than 150 nm, relevant colloidal stability in aqueous medium, satisfactory drug encapsulation efficiency, and retained emitting optical properties in the visible region of the electromagnetic spectrum. The assay on the BBB artificial model showed that a larger amount of DRV was able to cross BBB when incorporated in the PLGA NPs and to exert an enhanced inhibition of matrix metalloproteinase-9 (MMP-9) expression levels with respect to free DRV. The overall results reveal the great potential of this class of nanovectors of DRV for an efficacious treatment of HANDs.

Repurpose but also (nano)-reformulate! The potential role of nanomedicine in the battle against SARS-CoV2

The coronavirus disease-19 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) has taken the world by surprise. To date, a worldwide approved treatment remains lacking and hence in the context of rapid viral spread and the growing need for rapid action, drug repurposing has emerged as one of the frontline strategies in the battle against SARS-CoV2. Repurposed drugs currently being evaluated against COVID-19 either tackle the replication and spread of SARS-CoV2 or they aim at controlling hyper-inflammation and the rampaged immune response in severe disease. In both cases, the target for such drugs resides in the lungs, at least during the period where treatment could still provide substantial clinical benefit to the patient. Yet, most of these drugs are administered systemically, questioning the percentage of administered drug that actually reaches the lung and as a consequence, the distribution of the remainder of the dose to off target sites. Inhalation therapy should allow higher concentrations of the drug in the lungs and lower concentrations systemically, hence providing a stronger, more localized action, with reduced adverse effects. Therefore, the nano-reformulation of the repurposed drugs for inhalation is a promising approach for targeted drug delivery to lungs. In this review, we critically analyze, what nanomedicine could and ought to do in the battle against SARS-CoV2. We start by a brief description of SARS-CoV2 structure and pathogenicity and move on to discuss the current limitations of repurposed antiviral and immune-modulating drugs that are being clinically investigated against COVID-19. This account focuses on how nanomedicine could address limitations of current therapeutics, enhancing the efficacy, specificity and safety of such drugs. With the appearance of new variants of SARS-CoV2 and the potential implication on the efficacy of vaccines and diagnostics, the presence of an effective therapeutic solution is inevitable and could be potentially achieved via nano-reformulation. The presence of an inhaled nano-platform capable of delivering antiviral or immunomodulatory drugs should be available as part of the repertoire in the fight against current and future outbreaks.

Genistein as a regulator of signaling pathways and microRNAs in different types of cancers

Cancers are complex diseases orchestrated by a plethora of extrinsic and intrinsic factors. Research spanning over several decades has provided better understanding of complex molecular interactions responsible for the multifaceted nature of cancer. Recent advances in the field of next generation sequencing and functional genomics have brought us closer towards unravelling the complexities of tumor microenvironment (tumor heterogeneity) and deregulated signaling cascades responsible for proliferation and survival of tumor cells. Phytochemicals have begun to emerge as potent beneficial substances aimed to target deregulated signaling pathways. Isoflavonoid genistein is an essential phytochemical involved in regulation of key biological processes including those in different types of cancer. Emerging preclinical evidence have shown its anti-cancer, anti-inflammatory and anti-oxidant properties. Testing of this substance is in various phases of clinical trials. Comprehensive preclinical and clinical trials data is providing insight on genistein as a modulator of various signaling pathways both at transcription and translation levels. In this review we have explained the mechanistic regulation of several key cellular pathways by genistein. We have also addressed in detail various microRNAs regulated by genistein in different types of cancer. Moreover, application of nano-formulations to increase the efficiency of genistein is also discussed. Understanding the pleiotropic potential of genistein to regulate key cellular pathways and development of efficient drug delivery system will bring us a step towards designing better chemotherapeutics.

Role of nano-lipid formulation of CARP-1 mimetic, CFM-4.17 to improve systemic exposure and response in osimertinib resistant non-small cell lung cancer

BACKGROUND

EGFR mutated NSCLCs have been shown to employ the use of CARP-1 in overriding the signaling inhibition of tyrosine kinase inhibitors (such as Osimertinib). CFM 4.17 is a CARP-1 inhibitor which has a promising role in overcoming Tyrosine Kinase Inhibitor (TKI) resistance when used as a pre-treatment through promoting apoptosis. Lack of solubility, hydrophobicity leading to poor systemic exposure are the limitations of CFM 4.17. This can be overcome by nano lipid-based formulation (NLPF) of CFM 4.17 which can enhance systemic exposure in preclinical animal models as well as improve therapeutic efficacy in drug-resistant cancer cell lines.

METHODS

Molecular docking simulation studies were performed for CFM 4.17. CFM 4.17-NLPF was formulated by melt dispersion technique and optimized using a Box-Behnken designed surface response methodology approach using Design Expert and MATLAB. In vitro, CFM 4.17 release studies were performed in simulated gastric fluids (SGF-pH-1.2) and simulated intestinal fluids (SIF- pH-6.8). Cell viability assays were performed with HCC827 and H1975 Osimertinib resistant and non-resistant cells in 2D and 3D culture models of Non-small cell lung cancer to determine the effects of CFM 4.17 pre-treatment in Osimertinib response. In vivo pharmacokinetics in rats were performed measuring the effects of NLPF on CFM 4.17 to improve the systemic exposure.

RESULTS

CFM 4.17 was well accommodated in the active pocket of the active site of human EGFR tyrosine kinase. CFM 4.17 NLPF was optimized with robust experimental design with particle size less than 300 nm and % entrapment efficiency of 92.3 ± 1.23. Sustained diffusion-based release of CFM 4.17 was observed from NLPF in SGF and SIFs with Peppas and Higuchi based release kinetics, respectively. CFM 4.17 pretreatment improved response by decreasing IC50 value by 2-fold when compared to single treatment Osimertinib in both 2D monolayer and 3D spheroid assays in HCC827 and H1975 Osimertinib resistant and non-resistant cells of Non-small cell lung cancer. There were no differences between CFM 4.17 NLPF and suspension in 2D monolayer culture pretreatments; however, The 3D culture assays showed that CFM 4.17 NLPF improved combination sensitivity. Pharmacokinetic analysis showed that CFM 4.17 NLPF displayed higher AUCtot (2.9-fold) and Cmax (1.18-fold) as compared to free CFM 4.17. In contrast, the animal groups administered CFM 4.17 NLPF showed a 4.73-fold (in half-life) and a 3.07-fold increase (in MRT) when compared to equivalent dosed suspension.

CONCLUSION

We have successfully formulated CFM 4.17 NLPFs by robust RSM design approach displaying improved response through sensitizing cells to Osimertinib treatment as well as improving the oral bioavailability of CFM 4.17.

The preparation of lipid-based drug delivery system using melt extrusion

Melt extrusion of lipids is versatile with high applicability in the pharmaceutical industry. The formulations prepared can be easily customized depending on the requirements, and have the potential to open a window on personalized medicine.

Optimization of the synthetic parameters of lipid polymer hybrid nanoparticles dual loaded with darunavir and ritonavir for the treatment of HIV

Human Immunodeficiency Virus (HIV) is a global health concern to which nanomedicine approaches provide opportunities to improve the bioavailability of existing drugs used to treat HIV.In this article, lipid polymer hybrid nanoparticles (LPHNs) were developed as a system to provide a combination drug delivery of two leading antiretroviral drugs; darunavir (DRV) and its pharmacokinetic enhancer ritonavir (RTV).The LPHNs were designed with a poly(D, l-lactide-co-glycolide) (PLGA) core, and soybean lecithin (SBL) and Brij 78 as the stabilizers. The LPHNs were prepared by modified nanoprecipitation and the effect of synthetic conditions on the particle properties was studied, which included the Z-average diameter and polydispersity index of LPHNs in water and phosphate buffered saline, and the morphology of the particles. This investigation aimed to prepare a formulation that could be stored in its dry and redispersible form, therefore avoiding the challenges associated with storage of dispersions. The optimum ratio of stabilizer to polymer core was established at 20% w/w, and Brij 78 was found to be crucial in providing colloidal stability in physiological solutions; the minimum amount of Brij 78 required to provide stability in phosphate buffered saline was 70% w/w of the total stabilizer mass. Viable formulations of LPHNs containing DRV and RTV in the clinically used 8:1 ratio were prepared containing 20% w/w DRV with respect to the PLGA mass. The use of cryoprotectant, polyethylene glycol, combined with freeze-drying yielded LPHNs with a Z-average diameter of 150 nm when the particles were re-dispersed in water. The oral absorption behavior was assessed using an in vitro triple culture model. Whilst the use of cryoprotectant and freeze-drying led to no improvement of the transcellular permeability compared to the unformulated drugs, the non-freeze-dried samples with the highest soybean lecithin led to increased transcellular permeability, revealing the potential of LPHNs for enhancing HIV treatment.

Development of Solid Self-Microemulsifying System of Tizanidine Hydrochloride for Oral Bioavailability Enhancement: In Vitro and In Vivo Evaluation

The aim of the present investigation was to formulate self-microemulsifying drug delivery system (SMEDDS) tablets to enhance the oral bioavailability of tizanidine hydrochloride. SMEDDS was prepared by using Capmul G as the oil phase, Tween 20 as the surfactant, and propylene glycol as the co-surfactant. The optimized formulation was characterized by dilution test, % transmittance, thermodynamic stability, dye solubility, assay, globule size, zeta potential, and TEM. A dye solubility test confirmed the formation of o/w microemulsion. Optimized formulation of SMEDDS had a drug content of 98 ± 0.75% (3.2± 0.3 mg) and droplet size of 96.61 ± 2.3 nm. Dilution and centrifugation tests indicated the physical stability of the formulation. The optimized SMEDDS was mixed with Neusilin as adsorbent, microcrystalline cellulose as diluent, and magnesium stearate as flow promoter, and compressed into tablets. The prepared tablets passed the tests of weight variation, hardness, friability, and assay. In vitro dissolution test indicated sustained release of tizanidine hydrochloride from the SMEDDS tablet for a period of 4 h. In vivo pharmacokinetic studies performed on male New Zealand rabbits showed a 4.61-fold increase in bioavailability compared with the marketed formulation. Thus, the developed SMEDDS tablet proved to be capable of enhancing oral bioavailability of tizanidine hydrochloride. Graphical abstract.

Synthesis and Characterization of Long-Acting Darunavir Prodrugs

Antiretroviral therapy (ART) has improved the quality of life in patients infected with HIV-1. However, complete viral suppression within anatomical compartments remains unattainable. This is complicated by adverse side effects and poor adherence to lifelong therapy leading to the emergence of viral drug resistance. Thus, there is an immediate need for cellular and tissue-targeted long-acting (LA) ART formulations. Herein, we describe two LA prodrug formulations of darunavir (DRV), a potent antiretroviral protease inhibitor. Two classes of DRV prodrugs, M1DRV and M2DRV, were synthesized as lipophilic and hydrophobic prodrugs and stabilized into aqueous suspensions designated NM1DRV and NM2DRV. The formulations demonstrated enhanced intracellular prodrug levels with sustained drug retention and antiretroviral activities for 15 and 30 days compared to native DRV formulation in human monocyte-derived macrophages. Pharmacokinetics tests of NM1DRV and NM2DRV administered to mice demonstrated sustained drug levels in blood and tissues for 30 days. These data, taken together, support the idea that LA DRV with sustained antiretroviral responses through prodrug nanoformulations is achievable.

Nanotechnology approaches for delivery of cytochrome P450 substrates in HIV treatment

Introduction: Antiretroviral therapy (ART) has led to a significant reduction in HIV-1 morbidity and mortality. Many antiretroviral drugs (ARVs) are metabolized by cytochrome P450 (CYP) pathway, and the majority of these drugs are also either CYP inhibitors or inducers and few possess both activities. These CYP substrates, when used for HIV treatment in the conventional dosage form, have limitations such as low systemic bioavailability, potential drug-drug interactions, and short half-lives. Thus, an alternative mode of delivery is needed in contrast to conventional ARVs. Areas covered: In this review, we summarized the limitations of conventional ARVs in HIV treatment, especially for ARVs which are CYP substrates. We also discussed the preclinical and clinical studies using the nanotechnology strategy to overcome the limitations of these CYP substrates. The preclinical studies and clinical studies published from 2000 to February 2019 were discussed. Expert opinion: Since preclinical and clinical studies for prevention and treatment of HIV using nanotechnology approaches have shown considerable promise in recent years, nanotechnology could become an alternative strategy for daily oral therapy as a future treatment.

Labrasol-Enriched Nanoliposomal Formulation: Novel Approach to Improve Oral Absorption of Water-Insoluble Drug, Carvedilol

The purpose of the current study was to develop a novel liposomal formulation to improve the oral bioavailability of carvedilol, a Biopharmaceutics Classification System class II with poor aqueous solubility and extensive presystemic metabolism. Conventional and various surfactant-enriched carvedilol-loaded liposomes were prepared by thin film hydration technique and physicochemical properties of liposomes (including size, encapsulation efficiency, release behavior, and morphology) were evaluated. To assess the oral bioavailability, in vivo studies were carried out in eight groups of male Wistar rats (n = 6) and the drug plasma concentration was determined. Conventional and surfactant containing liposomes showed average particle size of 76-104 nm with a narrow size distribution, high encapsulation efficiency (80%≤) and a sustained release profile in simulated intestinal fluid. Compared to the suspension, conventional and Labrasol containing liposomes significantly improved the oral bioavailability and peak plasma concentration of carvedilol. Biocompatibility studies (cell cytotoxicity and histopathological analyses) showed that the enhancing effect might be achieved without any apparent toxicity in the intestine. Decreased oral absorption of carvedilol nanovesicles by using a chylomicron flow blocker indicated contribution of lymphatic transport in nanocapsules absorption. The results reported the successful development of biocompatible Labrasol-enriched carvedilol nanoliposomal formulation with a significant oral enhancement capability. Graphical Abstract ᅟ.

Darunavir-Loaded Lipid Nanoparticles for Targeting to HIV Reservoirs

Darunavir has a low oral bioavailability (37%) due to its lipophilic nature, metabolism by cytochrome P450 enzymes and P-gp efflux. Lipid nanoparticles were prepared in order to overcome its low bioavailability and to increase the binding efficacy of delivery system to the lymphoid system. Darunavir-loaded lipid nanoparticles were prepared using high-pressure homogenization technique. Hydrogenated castor oil was used as lipid. Peptide, having affinity for CD4 receptors, was grafted onto the surface of nanoparticles. The nanoparticles were evaluated for various parameters. The nanoparticles showed size of less than 200 nm, zeta potential of - 35.45 mV, and a high drug entrapment efficiency (90%). 73.12% peptide was found conjugated to nanoparticles as studied using standard BSA calibration plot. Permeability of nanoparticles in Caco-2 cells was increased by 4-fold in comparison to plain drug suspension. Confocal microscopic study revealed that the nanoparticles showed higher uptake in HIV host cells (Molt-4 cells were taken as model containing CD4 receptors) as compared to non-CD4 receptor bearing Caco-2 cells. In vivo pharmacokinetic in rats showed 569% relative increase in bioavailability of darunavir as compared to plain drug suspension. The biodistribution study revealed that peptide-grafted nanoparticles showed higher uptake in various organs (also in HIV reservoir organs namely the spleen and brain) except the liver compared to non-peptide-grafted nanoparticles. The prepared nanoparticles resulted in increased binding with the HIV host cells and thus could be promising carrier in active targeting of the drugs to the HIV reservoir.

Absorption Study of Genistein Using Solid Lipid Microparticles and Nanoparticles: Control of Oral Bioavailability by Particle Sizes

In this study, the effect of particle size of genistein-loaded solid lipid particulate systems on drug dissolution behavior and oral bioavailability was investigated. Genistein-loaded solid lipid microparticles and nanoparticles were prepared with glyceryl palmitostearate. Except for the particle size, other properties of genistein-loaded solid lipid microparticles and nanoparticles such as particle composition and drug loading efficiency and amount were similarly controlled to mainly evaluate the effect of different particle sizes of the solid lipid particulate systems on drug dissolution behavior and oral bioavailability. The results showed that genistein-loaded solid lipid microparticles and nanoparticles exhibited a considerably increased drug dissolution rate compared to that of genistein bulk powder and suspension. The microparticles gradually released genistein as a function of time while the nanoparticles exhibited a biphasic drug release pattern, showing an initial burst drug release, followed by a sustained release. The oral bioavailability of genistein loaded in solid lipid microparticles and nanoparticles in rats was also significantly enhanced compared to that in bulk powders and the suspension. However, the bioavailability from the microparticles increased more than that from the nanoparticles mainly because the rapid drug dissolution rate and rapid absorption of genistein because of the large surface area of the genistein-solid lipid nanoparticles cleared the drug to a greater extent than the genistein-solid lipid microparticles did. Therefore, the findings of this study suggest that controlling the particle size of solid-lipid particulate systems at a micro-scale would be a promising strategy to increase the oral bioavailability of genistein.

Corneal permeation properties of a charged lipid nanoparticle carrier containing dexamethasone

Drug delivery carriers can maintain effective therapeutic concentrations in the eye. To this end, we developed lipid nanoparticles (L/NPs) in which the surface was modified with positively charged chitosan, which engaged in hydrogen bonding with the phospholipid membrane. We evaluated in vitro corneal permeability and release characteristics, ocular irritation, and drug dynamics of modified and unmodified L/NPs in aqueous humor. The size of L/NPs was uniform and showed a narrow distribution. Corneal permeation was altered by the presence of chitosan and was dependent on particle size; the apparent permeability coefficient of dexamethasone increased by 2.7 and 1.8 times for chitosan-modified and unmodified L/NPs, respectively. In conclusion, a chitosan-modified system could be a promising method for increasing the ocular bioavailability of unmodified L/NPs by enhancing their retention time and permeation into the cornea. These findings provide a theoretical basis for the development of effective drug delivery systems in the treatment of ocular disease.