Nanoparticulation of poorly water soluble drugs using a wet-mill process and physicochemical properties of the nanopowders

Paclitaxel-nanocrystals-loaded network thermosensitive hydrogel for localised postsurgical recurrent of breast cancer after surgical resection

The recurrence of cancer after local surgery has been a difficult problem in the clinic for a long time. In recent years, local treatment via drug-loaded thermosensitive hydrogels have become a promising strategy to prevent cancer recurrence. Thus, a thermosensitive hydrogel based on poloxamer 407, poloxamer 188 and the bioadhesive excipient carbomer 974P was designed to locally release paclitaxel and prevent local tumour recurrence after direct smearing of the hydrogel at the site of injury in the surgical cavity. To improve the local drug concentration, paclitaxel was prepared into nanocrystals via a wet mill process. A series of studies were performed on this paclitaxel nanocrystal thermosensitive hydrogel (PTX-NCS-gel), including examination of its rheological properties and in vitro release and dissolution studies. Moreover, a postoperative tumour recurrence mouse model was established to evaluate the antitumour effects of this thermosensitive hydrogel. The results showed that PTX-NCS-gel had a clear, regular network structure with excellent temperature sensitivity and could be gelated within minutes at 33.1 °C. Additionally, the rheological property investigation indicated that the hydrogel has proper viscoelasticity and self-recovery ability. In vivo imaging showed that PTX-NCS-gel inhibited both local tumour recurrence and distant metastasis. Moreover, PTX-NCS-gel has the following advantages: it is more convenient to administer, avoids strong allergic responses, and has fewer side effects on the liver and spleen. This hydrogel has the potential to serve as a powerful auxiliary medication to prevent postoperative local tumour recurrence.

Current Status and Challenges of Analytical Methods for Evaluation of Size and Surface Modification of Nanoparticle-Based Drug Formulations

The present review discusses the current status and difficulties of the analytical methods used to evaluate size and surface modifications of nanoparticle-based pharmaceutical products (NPs) such as liposomal drugs and new SARS-CoV-2 vaccines. We identified the challenges in the development of methods for (1) measurement of a wide range of solid-state NPs, (2) evaluation of the sizes of polydisperse NPs, and (3) measurement of non-spherical NPs. Although a few methods have been established to analyze surface modifications of NPs, the feasibility of their application to NPs is unknown. The present review also examined the trends in standardization required to validate the size and surface measurements of NPs. It was determined that there is a lack of available reference materials and it is difficult to select appropriate ones for modified NP surface characterization. Research and development are in progress on innovative surface-modified NP-based cancer and gene therapies targeting cells, tissues, and organs. Next-generation nanomedicine should compile studies on the practice and standardization of the measurement methods for NPs to design surface modifications and ensure the quality of NPs.

A Novel Sprague-Dawley Rat Model Presents Improved NASH/NAFLD Symptoms with PEG Coated Vitexin Liposomes

Chronic liver disease (CLD) is a global threat to the human population, with manifestations resulting from alcohol-related liver disease (ALD) and non-alcohol fatty liver disease (NAFLD). NAFLD, if not treated, may progress to non-alcoholic steatohepatitis (NASH). Furthermore, inflammation leads to liver fibrosis, cirrhosis, and hepatocellular carcinoma. Vitexin, a natural flavonoid, has been recently reported for inhibiting NAFLD. It is a lipogenesis inhibitor and activates lipolysis and fatty acid oxidation. In addition, owing to its antioxidant properties, it appeared as a hepatoprotective candidate. However, it exhibits low bioavailability and low efficacy due to its hydrophobic nature. A novel rat model for liver cirrhosis was developed by CCL4/Urethane co-administration. Vitexin encapsulated liposomes were synthesized by the ‘thin-film hydration’ method. Polyethylene glycol (PEG) was coated on liposomes to enhance stability and stealth effect. The diseased rats were then treated with vitexin and PEGylated vitexin liposomes, administered intravenously and orally. Results ascertained the liposomal encapsulation of vitexin and subsequent PEG coating to be a substantial strategy for treating liver cirrhosis through oral drug delivery.

Quality by design prospects of pharmaceuticals application of double emulsion method for PLGA loaded nanoparticles

Abstract

QbD approach empowers the pharma researchers to minimize the number of experimental trials and time. It helps identify the significant, influential factors such as critical material attributes, critical formulation variables, and critical process parameters, which may significantly impact the quality of the products. Poly lactic-co-glycolic acid (PLGA), a biocompatible and biodegradable polymer, has gained an immense potential and wide range of applications as a carrier for manufacturing of polymeric nanoparticle drug delivery systems as per US-FDA and European Medicine Agency for drug delivery. The double emulsion method for preparing PLGA nanoparticles to encapsulate hydrophilic drugs has attracted interest in manufacturing processes. The double emulsion is a two-step process consisting of two different emulsification, making the process more complicated. The stability of nanoparticles obtained by a double emulsion method remains questionable due to the many formulations and process attributes. Currently, PLGA based nanoparticles prepared by a double emulsion technique are an alternative pharmaceutical manufacturing operation for getting the quality product by employing the Quality by Design approach. This present review has discussed the QbD elements to elucidate the effect of material attributes, formulation, and process variables on the critical quality attributes of the drug product, such as particle size distribution, encapsulation efficiency, etc. The components of a double emulsion, characteristics of drugs, polymers, and stabilizers used have been discussed in detail in this review.

Graphic abstract

Testing a Benchtop Wet-Milling Method for Preparing Nanoparticles and Suspensions as Hospital Formulations

In clinical practice, for elderly or pediatric patients who have difficulty swallowing, solid dosage forms such as tablets or capsules are crushed or unsealed, prepared as powder forms, and often administered as suspensions. However, because their dispersibility is poor, aggregation or precipitation occurs readily. Once precipitation and deposition happen, redispersion is difficult, which can limit patient and caretaker drug adherence. In this study, we attempted to prepare nanoparticles as a hospital formulation by a benchtop wet-milling method to obtain a suspension with high dispersibility. This is the first study to apply the wet-milling method to prepare the hospital formulation. We chose cefditoren pivoxil (CDTR-PI) as an experimental active pharmaceutical ingredient. CDTR-PI crystals were physically mixed with various water-soluble polymers such as polyvinylpyrrolidone, polyethylene oxide, hydroxypropyl cellulose, or hypromellose and wet-milled with a surface-active agent (sodium lauryl sulfate) under different conditions. The mean particle diameter of most of the samples was less than 200 nm. In FTIR spectra of ground samples, peak shifts suggesting inter- or intramolecular interactions between CDTR-PI and the other additive agents were not observed. Besides, the nanoparticle suspension had favorable dispersibility, as determined using a dispersion stability analyzer. Providing a suspension with high dispersibility makes dispense with the resuspension, the patient’s medication adherence would improve. These results show that suspended liquid formulations of active pharmaceutical ingredients could be obtained by the simple wet-milling method as hospital formulations.

Adsorption of a poorly water-soluble drug onto porous calcium silicate by the sealed heating method

To improve the bioavailability of orally-administered drug, solubilization of poorly water-soluble drug is important. The solubility of a drug in its amorphous form is known to be higher than in its crystalline form. In this study, we attempted to adsorb a sublimable drug onto porous calcium silicate (Florite®, FLR) or non-porous calcium silicate (NPCS) by the sealed heating (SH) method and evaporated (EV) method. Ibuprofen (IBU) was used as the poorly water-soluble, sublimable drug. The physicochemical properties of samples were investigated using powder X-ray diffractometry (PXRD), differential scanning calorimetry (DSC), Fourier-transform infrared spectroscopy (FTIR), and dissolution test. From the PXRD and DSC results, IBU crystals were adsorbed and amorphized by the SH and EV methods with FLR. From the results of FTIR, the shift to a higher frequency by the carbonyl stretching vibration band of IBU suggests an intermolecular interaction between IBU and FLR. In SH with FLR, improved solubilization was observed. IBU adsorbed onto FLR showed a greater dissolution rate than the IBU crystals or NPCS. Thus, the petal-like structure of FLR may be an effective method to adsorb IBU onto FLR using the SH method.

Formation of nanosuspensions in bottom-up approach: theories and optimization

BACKGROUND

Nanosuspensions, liquid dispersions with nanometer size distribution, are becoming trendy in pharmaceutical practice to formulate poorly water-soluble drugs and to enhance their bioavailability. Generally, nanosuspensions are produced in two main approaches; top-down or bottom-up. The former is based on size-reduction of large particles via milling or high pressure homogenization. The latter is focused on the mechanisms of nucleation and particle growth.

METHODS

In this review, the critical factors influencing the kinetics or dynamics of nucleation and growth are discussed. Subsequently, the mechanisms of nanosuspension instability as well as strategies for stabilization are elaborated. Furthermore, the effects of stabilizers on key parameters of instability as well as the process of choosing an appropriate stabilizer is discussed.

RESULTS

Steric and electrostatic stabilizations or combination of them is essential for nanosuspensions formulation to prevent coagulation. Accordingly, some characteristics of stabilizers play critical role on stability and optimization of nanosuspensions; i.e., HLB and concentration. Nevertheless, after reviewing various articles, it is ascertained that each formulation requires individual selection of surfactants according to the parameters of the particle surface and the medium.

CONCLUSIONS

Based on the results, application of excipients such as stabilizers requires proper optimization of type and concentration. This implies that each formulation requires its own optimization process. Graphical Abstract ᅟ.

Improved water dispersibility and photostability in folic acid nanoparticles with transglycosylated naringin using combined processes of wet-milling and freeze-drying

We successfully prepared folic acid (FA) nanoparticles with excellent dispersibility and photostability using a combination of bead milling and freeze-drying with transglycosylated naringin (Naringin-G), a newly developed transglycosylated food additive. Poly-vinyl pyrrolidon (PVP) was used for comparison with Naringin-G. Water dispersibility and photostability of the freeze-dried formulations were assessed. The dispersibility and physicochemical properties of nanoparticle formulations were evaluated using dynamic light scattering, powder X-ray diffraction (PXRD), and small-angle X-ray scattering (SAXS). Results indicated that the median particle size of FA in the slurry bead milled with Naringin-G decreased notably with time and fell below 100 nm after milling for 300 min. Further, FA nanoparticles with Naringin-G were stable without aggregation following re-dispersion of freeze-dried FA formulations in water. Contrarily, the addition of PVP did not prevent the aggregation of FA nanoparticles following re-dispersion of freeze-dried FA formulations. Solid structures of freeze-dried FA formulations with Naringin-G or PVP were assessed using PXRD and SAXS. PXRD patterns of all freeze-dried formulations highlighted broadening and weakening of peaks, indicating a decrease in FA crystallinity following bead milling, regardless of the additive concentration of Naringin-G and PVP. The scattering intensity profiles of FA formulations with PVP dramatically decreased after milling, whereas FA formulations with Naringin-G did not exhibit changes in SAXS patterns. FA formulations with Naringin-G registered faster enhancement in release rate than PVP in pH 1.2 buffer solutions. The release rate of freeze-dried FA formulation with Naringin-G exhibited at least five-fold enhancement when compared to untreated FA. FA formulation with Naringin-G was stable to photodegradation under fluorescent light. Naringin-G prevented photodegradation of FA due to its antioxidant effect and scavenged radicals. These findings indicated that freeze-dried FA formulation with Naringin-G can improve its water-dispersibility and photodegradation due to the effectiveness of Naringin-G as a dispersant and cryoprotectant.

Utilization of Lignocellulosic Biomass via Novel Sustainable Process

In this review, we show novel methods for utilizing lignocellulosic biomass, polysaccharides, and lignin. Firstly, the simultaneous enzymatic saccharification and comminution (SESC) of plant materials is described as an extraction method for lignocellulosic biomass that does not require toxic reagents or organic solvents. Secondly, we demonstrate the material utilization of non-deteriorated lignocellulosic biomass extracted by SESC, such as for sugar and ethanol synthesis, and as a heatproof filler. Finally, we exhibit the use of a functional monomer (e.g., in disinfection chemicals, cesium chelation, and building blocks for polymers), 2-pyrone-4,6-dicarboxylic acid, derived from lignin via metabolic degradation.

Polymorphism of chlorpropamide on liquid-assisted mechanical treatment: choice of liquid and type of mechanical treatment matter

Different types of mechanical treatment (tableting, grinding, milling, etc.) are important technological operations in the pharmaceutical industry.

In Vitro and In Vivo Evaluation of PEGylated Layer-by-Layer Polyelectrolyte-Coated Paclitaxel Nanocrystals

Drug nanocrystals (NCs) are colloidal dispersions composed almost entirely of drug. As such, there is substantial interest in targeting them to diseased tissues, where they can locally deliver high doses of the therapeutic. However, because of their uncontrolled dissolution characteristics in vivo and uptake by the monomolecular phagocyte system, achieving tumor accumulation is challenging. To address these issues, a layer-by-layer approach is adopted to coat paclitaxel NCs with alternating layers of oppositely charged polyelectrolytes, using a PEGylated copolymer as the top layer. The coating successfully slows down dissolution in comparison to the noncoated NCs and to Abraxane (an approved paclitaxel nanoformulation), provides colloidal stability in physiologically relevant media, and has no intrinsic effect on cell viability at the concentrations tested. Nevertheless, their pharmacokinetic and biodistribution profile indicates that the NCs are rapidly cleared from the bloodstream followed by accumulation in the mononuclear phagocyte system organs (i.e., liver and spleen). This is hypothesized to be a consequence of the shedding of the PEGylated polyelectrolyte from the NCs' surface. While therapeutic efficacy was not investigated (due to poor tumor accumulation), overall, this work questions whether approaches that rely solely on electrostatic interactions for retaining coatings on the surfaces of NCs are appropriate for use in vivo.

Nanomilling of Drugs for Bioavailability Enhancement: A Holistic Formulation-Process Perspective

Preparation of drug nanoparticles via wet media milling (nanomilling) is a very versatile drug delivery platform and is suitable for oral, injectable, inhalable, and buccal applications. Wet media milling followed by various drying processes has become a well-established and proven formulation approach especially for bioavailability enhancement of poorly water-soluble drugs. It has several advantages such as organic solvent-free processing, tunable and relatively high drug loading, and applicability to a multitude of poorly water-soluble drugs. Although the physical stability of the wet-milled suspensions (nanosuspensions) has attracted a lot of attention, fundamental understanding of the process has been lacking until recently. The objective of this review paper is to present fundamental insights from available published literature while summarizing the recent advances and highlighting the gap areas that have not received adequate attention. First, stabilization by conventionally used polymers/surfactants and novel stabilizers is reviewed. Then, a fundamental understanding of the process parameters, with a focus on wet stirred media milling, is revealed based on microhydrodynamic models. This review is expected to bring a holistic formulation-process perspective to the nanomilling process and pave the way for robust process development scale-up. Finally, challenges are indicated with a view to shedding light on future opportunities.

Inhibition of Photodegradation of Highly Dispersed Folic Acid Nanoparticles by the Antioxidant Effect of Transglycosylated Rutin

We developed highly dispersible and photostable nanoparticles of vitamin, folic acid (FA). FA was wet bead milled with milling and dispersing adjuvants and transglycosylated compounds such as α-glucosyl hesperidin (Hesperidin-G) and rutin (Rutin-G), which solubilized FA. The milled slurries of FA particles with transglycosylated compounds consisted of nanosized particles with a median diameter of <100 nm. The lyophilized formulations of these slurries retained their nanometer size after resuspension in water with no aggregation. The apparent solubility of FA in these formulations was 100-fold higher than that of untreated FA. The solubilizing effect of Rutin-G may affect the particle size reduction and dispersibility of FA. The photostability results showed that the strong antioxidant activity of Rutin-G substantially increased the photostability of FA solution. On the basis of these results, bead milling of FA with Rutin-G is a promising technique for developing highly dispersible, photostable nanoparticle FA formulations.

Enhanced bioavailability of danazol nanosuspensions by wet milling and high-pressure homogenization

Introduction:

The majority of drugs obtained through synthesis and development show poor aqueous solubility and dissolution velocity, resulting in reduced bioavailability of drugs. Most of these problems arise from formulation-related performance issues, and an efficient way to overcome these obstacles and to increase dissolution velocity is to reduce the particle size of drug substances to form drug nanosuspensions.

Materials and Methods:

Danazol nanosuspensions were prepared by wet milling (WM) and high-pressure homogenization (HPH) methods. The nanosuspensions obtained using these fabrication methods were analyzed for their particle size, surface charge, and the crystallinity of the product was assessed by X-ray diffraction (XRD) and differential scanning calorimetry techniques. To determine in vitro and in vivo performances of the prepared nanosuspensions, dissolution velocity, and bioavailability studies were performed.

Results:

Particle size and zeta potential analysis showed the formation of nanosized particles with a negative charge on the surface. XRD depicted the nanocrystalline nature of danazol with low diffraction intensities. With increased surface area and saturation solubility, the nanosuspensions showed enhanced dissolution velocity and oral bioavailability in rats when compared to the bulk danazol suspension.

Conclusions:

The results suggest that the preparation of nanosuspensions by WM or HPH is a promising approach to formulate new drugs or to reformulate existing drugs with poorly water-soluble properties.

A brief literature and patent review of nanosuspensions to a final drug product

Particle size reduction can be used for enhancing the dissolution of poorly water-soluble drugs in order to enhance bioavailability. In nanosuspensions, the particle size of the drug is reduced to nanometer size. Nanosuspensions after downstream processing into drug products have successfully shown its impact on formulation design, the augmentation of product life cycle, patent life, and therapeutic efficacy. Formulation considerations for the nanosuspension formulation, its processing into a solid form, and aspects of material characterization are discussed. Technology assessments and feasibility of upstream processes for nanoparticle creation, and subsequently transformation into a drug product via the downstream processes have been reviewed. This paper aims to bridge formulation and process considerations along with patent reviews and may provide further insight into understanding the science and the white space. An analysis of current patent outlook and future trends is described to fully understand the limitations and opportunities in intellectual property generation.

NanoClusters surface area allows nanoparticle dissolution with microparticle properties

Poorly water-soluble drugs comprise the majority of new drug molecules. Nanoparticle agglomerates, called NanoClusters, can increase the dissolution rate of poorly soluble compounds by increasing particle surface area. Budesonide and danazol, two poorly soluble steroids, were studied as model compounds. NanoCluster suspensions were made using a Netzsch MiniCer media mill with samples collected between 5 and 15 h and lyophilized. Differential scanning calorimetry (DSC) and powder X-ray Diffraction were used to evaluate the physicochemical properties of the powders, and Brunauer, Emmett and Teller (BET) analysis was used to determine surface area. Scanning electron microscopy confirmed NanoClusters were between 1 and 5 μm. NanoCluster samples showed an increase in dissolution rate compared with the micronized stock and similar to a dried nanoparticle suspension. BET analysis determined an increase in surface area of eight times for budesonide NanoClusters and 10-15 times for danazol NanoClusters compared with the micronized stock. Melting temperatures decreased with increased mill time of NanoClusters by DSC. The increased surface area of NanoClusters provides a potential micron-sized alternative to nanoparticles to increase dissolution rate of poorly water-soluble drugs.

Recent advancements in mechanical reduction methods: particulate systems

The screening of new active pharmaceutical ingredients (APIs) has become more streamlined and as a result the number of new drugs in the pipeline is steadily increasing. However, a major limiting factor of new API approval and market introduction is the low solubility associated with a large percentage of these new drugs. While many modification strategies have been studied to improve solubility such as salt formation and addition of cosolvents, most provide only marginal success and have severe disadvantages. One of the most successful methods to date is the mechanical reduction of drug particle size, inherently increasing the surface area of the particles and, as described by the Noyes-Whitney equation, the dissolution rate. Drug micronization has been the gold standard to achieve these improvements; however, the extremely low solubility of some new chemical entities is not significantly affected by size reduction in this range. A reduction in size to the nanometric scale is necessary. Bottom-up and top-down techniques are utilized to produce drug crystals in this size range; however, as discussed in this review, top-down approaches have provided greater enhancements in drug usability on the industrial scale. The six FDA approved products that all exploit top-down approaches confirm this. In this review, the advantages and disadvantages of both approaches will be discussed in addition to specific top-down techniques and the improvements they contribute to the pharmaceutical field.

Novel ultra-cryo milling and co-grinding technique in liquid nitrogen to produce dissolution-enhanced nanoparticles for poorly water-soluble drugs

A novel ultra-cryo milling micronization technique for pharmaceutical powders using liquid nitrogen (LN2 milling) was used to grind phenytoin, a poorly water-soluble drug, to improve its dissolution rate. LN2 milling produced particles that were much finer and more uniform in size and shape than particles produced by jet milling. However, the dissolution rate of LN2-milled phenytoin was the same as that of unground phenytoin due to agglomeration of the submicron particles. To overcome this, phenytoin was co-ground with polyvinylpyrrolidone (PVP). The dissolution rate of co-ground phenytoin was much higher than that of original phenytoin, single-ground phenytoin, a physical mixture of phenytoin and PVP, or jet-milled phenytoin. X-Ray diffraction showed that the crystalline state of mixtures co-ground by LN2 milling remained unchanged. The equivalent improvement in dissolution, whether phenytoin was co-ground or separately ground and then mixed with PVP, suggested that even when co-ground, the grinding of PVP and phenytoin occurs essentially independently. Mixing original PVP with ground phenytoin provided a slight improvement in dissolution, indicating that the particle size of PVP is important for improving dissolution. When mixed with ground phenytoin, PVP ground by LN2 milling aided the wettability and dispersion of phenytoin, enhancing utilization of the large surface area of ground phenytoin. Co-grinding phenytoin with other excipients such as Eudragit L100, hypromellose, hypromellose acetate-succinate, microcrystalline cellulose, hydroxypropylcellulose and carboxymethyl cellulose also improved the dissolution profile, indicating an ultra-cryo milling and co-grinding technique in liquid nitrogen has a broad applicability of the dissolution enhancement of phenytoin.

Continuous production of drug nanoparticle suspensions via wet stirred media milling: a fresh look at the Rehbinder effect

Nanoparticles of BCS Class II drugs are produced in wet stirred media mills operating in batch or recirculation mode with the goal of resolving the poor water-solubility issue. Scant information is available regarding the continuous production of drug nanoparticles via wet media milling. Griseofulvin and Naproxen were milled in both recirculation mode and multi-pass continuous mode to study the breakage dynamics and to determine the effects of suspension flow rate. The evolution of the median particle size was measured and described by an empirical breakage model. We found that these two operation modes could produce drug nanosuspensions with similar particle size distributions (PSDs). A reduced suspension flow rate slowed the breakage rate and led to a wider PSD and more differentiation between the two operation modes. The latter part of this study focused on the roles of stabilizers (hydroxypropyl cellulose and sodium lauryl sulfate) and elucidation of the so-called Rehbinder effect (reduction in particle strength due to adsorbed stabilizers such as polymers and surfactants). Milling the drugs in the absence of the stabilizers produced primary nanoparticles and their aggregates, while milling with the stabilizers produced smaller primary nanoparticles with minimal aggregation. Using laser diffraction, BET nitrogen adsorption, scanning electron microscopy imaging, and a microhydrodynamic analysis of milling, this study, for the first time, provides sufficient evidence for the existence of the Rehbinder effect during the milling of drugs. Not only do the polymers and surfactants allow proper stabilization of the nanoparticles in the suspensions, but they also do facilitate drug particle breakage.

Physical and chemical stability of drug nanoparticles

As nano-sizing is becoming a more common approach for pharmaceutical product development, researchers are taking advantage of the unique inherent properties of nanoparticles for a wide variety of applications. This article reviews the physical and chemical stability of drug nanoparticles, including their mechanisms and corresponding characterization techniques. A few common strategies to overcome stability issues are also discussed.

Iodinated NanoClusters as an inhaled computed tomography contrast agent for lung visualization

Improvements to contrast media formulations may be an effective way to increase the accuracy and effectiveness of thoracic computed tomography (CT) imaging in disease evaluation. To achieve contrast enhancement in the lungs, a relatively large localized concentration of contrast media must be delivered. Inhalation offers a noninvasive alternative to intrapleural injections for local lung delivery, but effective aerosolization may deter successful imaging strategies. Here, NanoCluster technology was applied to N1177, a diatrizoic acid derivative, to formulate low density nanoparticle agglomerates with aerodynamic diameters <or=5 microm. Excipient-free N1177 NanoCluster powders were delivered to rats by insufflation or inhalation and scanned using CT up to 1 h post dose. CT images after inhalation showed a approximately 120 (HU) Hounsfield units contrast increase in the lungs, which was more than sufficient contrast for thoracic CT imaging. Lung tissue histology demonstrated that N1177 NanoClusters did not damage the lungs. NanoCluster particle engineering technology offers a novel approach to safely and efficiently disseminate high concentrations of contrast agents to the lung periphery.

Analyses of nanoformulated antiretroviral drug charge, size, shape and content for uptake, drug release and antiviral activities in human monocyte-derived macrophages

Long-term antiretroviral therapy (ART) for human immunodeficiency virus type one (HIV-1) infection shows limitations in pharmacokinetics and biodistribution while inducing metabolic and cytotoxic aberrations. In turn, ART commonly requires complex dosing schedules and leads to the emergence of viral resistance and treatment failures. We posit that the development of nanoformulated ART could preclude such limitations and affect improved clinical outcomes. To this end, we wet-milled 20 nanoparticle formulations of crystalline indinavir, ritonavir, atazanavir, and efavirenz, collectively referred to as "nanoART," then assessed their performance using a range of physicochemical and biological tests. These tests were based on cell-nanoparticle interactions using monocyte-derived macrophages and their abilities to uptake and release nanoformulated drugs and affect viral replication. We demonstrate that physical characteristics such as particle size, surfactant coating, surface charge, and most importantly shape are predictors of cell uptake and antiretroviral efficacy. These studies bring this line of research a step closer to developing nanoART that can be used in the clinic to affect the course of HIV-1 infection.