Molecular simulation driven experiment for formulation of fixed dose combination of Darunavir and Ritonavir as anti-HIV nanosuspension

Active-reset protein sensors enable continuous in vivo monitoring of inflammation

Continuous measurement of proteins in vivo is important for real-time disease management and prevention. Implantable sensors for monitoring small molecules such as glucose have been available for more than a decade. However, analysis of proteins remains an unmet need because the lower physiological levels require that sensors have high affinities, which are linked to long complexation half-lives (t1/2 ~20 hours) and slow equilibration when concentrations decrease. We report active-reset sensors by use of high-frequency oscillations to accelerate dissociation, which enables regeneration of the unbound form of the sensor within 1 minute. When implemented within implanted devices, these sensors allow for real-time, in vivo monitoring of proteins within interstitial fluid. Active-reset protein sensors track biomarker levels on a physiological timescale for inflammation monitoring in living animals.

Coumarin Derivative Hybrids: Novel Dual Inhibitors Targeting Acetylcholinesterase and Monoamine Oxidases for Alzheimer's Therapy

Multi-target-directed ligands (MTDLs) represent a promising frontier in tackling the complexity of multifactorial pathologies like Alzheimer's disease (AD). The synergistic inhibition of MAO-B, MAO-A, and AChE is believed to enhance treatment efficacy. A novel coumarin-based molecule substituted with O-phenylpiperazine via three- and four-carbon linkers at the 5- and 7-positions, has been identified as an effective MTDL against AD. Employing a medicinal chemistry approach, combined with molecular docking, molecular dynamic simulation, and ΔGbind estimation, two series of derivatives emerged as potent MTDLs: 8-acetyl-7-hydroxy-4-methylcoumarin (IC50: 1.52-4.95 μM for hAChE, 6.97-7.65 μM for hMAO-A) and 4,7-dimethyl-5-hydroxycoumarin (IC50: 1.88-4.76 μM for hMAO-B). They displayed binding free energy (ΔGbind) of -76.32 kcal/mol (11) and -70.12 kcal/mol (12) against AChE and -66.27 kcal/mol (11) and -62.89 kcal/mol (12) against MAO-A. It is noteworthy that compounds 11 and 12 demonstrated efficient binding to both AChE and MAO-A, while compounds 3 and 10 significantly reduced MAO-B and AChE aggregation in vitro. These findings provide structural templates for the development of dual MAO and AChE inhibitors for the treatment of neurodegenerative diseases.

Examine stability polyvinyl alcohol-stabilized nanosuspensions to overcome the challenge of poor drug solubility utilizing molecular dynamic simulation

The pharmaceutical industry faces a significant challenge from the low water solubility of nearly 90% of newly developed Active Pharmaceutical Ingredients (APIs). Despite extensive efforts to improve solubility, approximately 40% of these APIs encounter commercialization hurdles, impacting drug efficacy. In this context, a promising strategy will be introduced in which nanosuspensions, particularly polyvinyl alcohol (PVA) as a stabilizer, are applied to increase drug solubility. In this work using molecular dynamics simulations, the nanosuspension of four poorly water-soluble drugs (flurbiprofen, bezafibrate, miconazole, and phenytoin) stabilized with PVA is investigated. The simulation data showed van der Waals energies between polyvinyl alcohol with flurbiprofen and bezafibrate are - 101.12 and - 58.42 kJ/mol, respectively. The results indicate that PVA is an effective stabilizer for these drugs, and superior interactions are obtained with flurbiprofen and bezafibrate. The study also explores the impact of PVA on water molecule diffusion, providing insights into the stability of nanosuspensions. Obtained results also provide valuable insights into hydrogen bond formation, diffusion coefficients, and nanosuspension stability, contributing to the rational design and optimization of pharmaceutical formulations.

An emerging terpolymeric nanoparticle pore former as an internal recrystallization inhibitor of celecoxib in controlled release amorphous solid dispersion beads: Experimental studies and molecular dynamics analysis

Solid oral controlled release formulations feature numerous clinical advantages for drug candidates with adequate solubility and dissolution rate. However, most new chemical entities exhibit poor water solubility, and hence are exempt from such benefits. Although combining drug amorphization with controlled release formulation is promising to elevate drug solubility, like other supersaturating systems, the problem of drug recrystallization has yet to be resolved, particularly within the dosage form. Here, we explored the potential of an emerging, non-leachable terpolymer nanoparticle (TPN) pore former as an internal recrystallization inhibitor within controlled release amorphous solid dispersion (CRASD) beads comprising a poorly soluble drug (celecoxib) reservoir and insoluble polymer (ethylcellulose) membrane. Compared to conventional pore former, polyvinylpyrrolidone (PVP), TPN-containing membranes exhibited superior structural integrity, less crystal formation at the CRASD bead surface, and greater extent of celecoxib release. All-atom molecular dynamics analyses revealed that in the presence of TPN, intra-molecular bonding, crystal formation tendency, diffusion coefficient, and molecular flexibility of celecoxib were reduced, while intermolecular H-bonding was increased as compared to PVP. This work suggests that selection of a pore former that promotes prolonged molecular separation within a nanoporous controlled release membrane structure may serve as an effective strategy to enhance amorphicity preservation inside CRASD.

Drug Nanocrystals: A Delivery Channel for Antiviral Therapies

Viral infections represent a significant threat to global health due to their highly communicable and potentially lethal nature. Conventional antiviral interventions encounter challenges such as drug resistance, tolerability issues, specificity concerns, high costs, side effects, and the constant mutation of viral proteins. Consequently, the exploration of alternative approaches is imperative. Therefore, nanotechnology-embedded drugs excelled as a novel approach purporting severe life-threatening viral disease. Integrating nanomaterials and nanoparticles enables ensuring precise drug targeting, improved drug delivery, and fostered pharmacokinetic properties. Notably, nanocrystals (NCs) stand out as one of the most promising nanoformulations, offering remarkable characteristics in terms of physicochemical properties (higher drug loading, improved solubility, and drug retention), pharmacokinetics (enhanced bioavailability, dose reduction), and optical properties (light absorptivity, photoluminescence). These attributes make NCs effective in diagnosing and ameliorating viral infections. This review comprises the prevalence, pathophysiology, and resistance of viral infections along with emphasizing on failure of current antivirals in the management of the diseases. Moreover, the review also highlights the role of NCs in various viral infections in mitigating, diagnosing, and other NC-based strategies combating viral infections. In vitro, in vivo, and clinical studies evident for the effectiveness of NCs against viral pathogens are also discussed.

Enhanced tissue distribution of ritonavir-loaded nanostructured lipid carriers-recommending its dose reduction

Human immunodeficiency virus (HIV) mainly attacks lymphocytes of the human immune system. The untreated infection leads to acquired immune deficiency syndrome (AIDS). Ritonavir (RTV) belongs to protease inhibitors (PIs), the crucial contributors of the combination therapy used in the treatment of HIV that is called highly active antiretroviral therapy (HAART). Formulations targeting the lymphatic system (LS) play a key role in delivering and maintaining therapeutic drug concentrations in HIV reservoirs. In our previous study, we developed RTV-loaded nanostructured lipid carriers (NLCs), which contain the natural antioxidant alpha-tocopherol (AT). In the current study, the cytotoxicity of the formulation was studied in HepG2, MEK293, and H9C2 cell lines. The formulation efficacy to reach the LS was evaluated through a cycloheximide-injected chylomicron flow blockade model in Wistar rats. Biodistribution and toxicity studies were conducted in rodents to understand drug distribution patterns in various organs and to establish the safety profile of the optimized formulation (RTV-NLCs). From the MTT assay, it was found that the cell viability of the formulation is comparable with the pure drug (RTV-API). More than 2.5-folds difference in AUC was observed in animals treated with RTV-NLCs with and without cycloheximide injection. Biodistribution studies revealed higher drug exposure in the lymphoidal organs with the RTV-NLCs. No significant increase in serum biomarkers for hepatotoxicity was observed in rats dosed with the RTV-NLCs. The current study reveals the lymphatic uptake of the RTV-NLCs and their safety in rodents. As the tissue distribution of RTV-NLCs is high, hence re-adjusting the RTV-NLCs dose to get the response equivalent to RTV-API may be more beneficial with respect to its safety and efficacy.

In Silico Screening as a Tool to Prepare Drug-Drug Cocrystals of Ibrutinib-Ketoconazole: a Strategy to Enhance Their Solubility Profiles and Oral Bioavailability

Ibrutinib (IBR) is a biopharmaceutical classification system (BCS) class II drug and an irreversible Bruton's tyrosine kinase (BTK) inhibitor. IBR has an extremely low oral bioavailability due to the activity of the CYP3A4 enzyme. The current intention of the research was to enhance solubility followed by oral bioavailability of IBR using the hot melt extrusion (HME) technique by formulating drug-drug cocrystals (DDCs). Ketoconazole (KET) is an active CYP3A4 inhibitor and was selected based on computational studies and solubility parameter prediction. Differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FT-IR), powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA), proton nuclear magnetic resonance (1H NMR), and scanning electron microscopy (SEM) evaluations were employed for estimating the formation of IBR-KET DDCs. The IBR-KET DDC system was discovered to have a hydrogen bond (H-bond) and π-π-stacking interactions, in accordance with the computational results. Further, IBR-KET DDCs showed enhanced solubility, stability, powder dissolution, in vitro release, and flow properties. Furthermore, IBR-KET-DDCs were associated with enhanced cytotoxic activity in K562-CCL-243 cancer cell lines when compared with IBR and KET alone. In vivo pharmacokinetic studies have shown an enhanced oral bioavailability of up to 4.30 folds of IBR and 2.31 folds of KET through IBR-KET-DDCs compared to that of the IBR and KET suspension alone. Thus, the prepared IBR-KET-DDCs using the HME technique stand as a favorable drug delivery system that augments the solubility and oral bioavailability of IBR along with KET.

Factors affecting the preparation of nanocrystals: characterization, surface modifications and toxicity aspects

INTRODUCTION

The fabrication of well-defined nanocrystals in size and form is the focus of much investigation. In this work, we have critically reviewed several recent instances from the literature that shows how the production procedure affects the physicochemical properties of the nanocrystals.

AREAS COVERED

Scopus, MedLine, PubMed, Web of Science, and Google Scholar were searched for peer-review articles published in the past few years using different key words. Authors chose relevant publications from their files for this review. This review focuses on the range of techniques available for producing nanocrystals. We draw attention to several recent instances demonstrating the impact of various process and formulation variables that affect the nanocrystals' physicochemical properties. Moreover, various developments in the characterization techniques explored for nanocrystals concerning their size, morphology, etc. have been discussed. Last but not least, recent applications, the effect of surface modifications, and the toxicological traits of nanocrystals have also been reviewed.

EXPERT OPINION

The selection of an appropriate production method for the formation of nanocrystals, together with a deep understanding of the relationship between the drug's physicochemical properties, unique features of the various formulation alternatives, and anticipated in-vivo performance, would significantly reduce the risk of failure during human clinical trials that are inadequate.

Hot-melt extruded in situ gelling systems (MeltDrops Technology): Formulation development, in silico modelling and in vivo studies

In situ gelling systems (ISGS) can prolong retention time and bioavailability of ophthalmic solutions. The complexity and cost of ISGS avert their industrial scale-up and clinical implementation. In this study, we demonstrate novel application of hot-melt extrusion (HME) technology for continuous manufacturing of ISGS (MeltDrops Technology). Timolol maleate (TIM) and dorzolamide hydrochloride (DRZ) loaded MeltDrops were successfully developed using HME for glaucoma management, thereby resolving issues with batch manufacturing of ISGS, prolonging retention time thus improving bioavailability. The MeltDrops technology involves one-step, i.e., passing all the ingredients through an extruder at a screw speed between 20-50 rpm and barrel temperature of 80 °C. The comparative evaluation of MeltDrops and batch-processed ISGS demonstrated that MeltDrops exhibited better physical and chemical content uniformity. The extrusion temperature and screw speed were critical factors influencing content uniformity and properties of the MeltDrops. MeltDrops showed sustained drug release for >12 hours in vitro (TIM= 83.07%; DRZ = 60.43%, 12hours) versus marketed eyedrops. The developed MeltDrops followed Peppas-Sahlin model, combining Fickian diffusion and swelling processes. The in vivo study in New Zealand rabbits revealed superior effectiveness and safety of the MeltDrops as compared to the marketed eyedrops. Herein we conclude, MeltDrops would serve as a cutting-edge platform technology that can be used to manufacture various ISGS with one-step processability, cost-effectiveness, and improved product quality, which are otherwise processed by batch manufacturing that involves numerous complex processing steps.

Effervescence-induced amorphous solid dispersions with improved drug solubility and dissolution

The current study aimed to investigate drug carrier miscibility in pharmaceutical solid dispersions (SD) and include the effervescent system, i.e. Effervescence-induced amorphous solid dispersions (ESD), to enhance the solubility of a poorly water-soluble Glibenclamide (GLB). Kollidon VA 64, PEG-3350, and Gelucire-50/13 were selected as the water-soluble carriers. The miscibility of the drug-carrier was predicted by molecular dynamics simulation, Hansen solubility parameters, Flory-Huggins theory, and Gibb's free energy. Solid dispersions were prepared by microwave, solvent evaporation, lyophilization, and Hot Melt Extrusion (HME) methods. The prepared solid dispersions were subjected to solubility, in-vitro dissolution, and other characterization studies. The in-silico and theoretical approach suggested that the selected polymers exhibited better miscibility with GLB. Solid-state characterizations like FTIR and ¹H NMR proved the formation of intermolecular hydrogen bonding between the drug and carriers, which was comparatively higher in ESDs than SDs. DSC, PXRD, and microscopic examination of GLB and SDs confirmed the amorphization of GLB, which was higher in ESDs than SDs. Gibb's free energy concept suggested that the prepared solid dispersions will be stable at room temperature. Ex-vivo intestinal absorption study on optimized ESDs prepared with Kollidon VA64 using the HME technique exhibited a higher flux and permeability coefficient than the pure drug suggesting a better drug delivery. The drug-carrier miscibility was successfully studied in SDs of GLB. The addition of the effervescent agent further enhanced the solubility and dissolution of GLB. Additionally, this might exhibit a better bioavailability, confirmed by ex-vivo intestinal absorption study.

Drug-Carrier Miscibility in Solid Dispersions of Glibenclamide and a Novel Approach to Enhance Its Solubility Using an Effervescent Agent

The present research aims to investigate the miscibility, physical stability, solubility, and dissolution rate of a poorly water-soluble glibenclamide (GLB) in solid dispersions (SDs) with hydrophilic carriers like PEG-1500 and PEG-50 hydrogenated palm glycerides (Acconon). Mathematical theories such as Hansen solubility parameters, Flory Huggins theory, Gibbs free energy, and the in silico molecular dynamics simulation study approaches were used to predict the drug-carrier miscibility. To increase the solubility further, the effervescence technique was introduced to the conventional solid dispersions to prepare effervescent solid dispersions (ESD). Solid dispersions (SDs) were prepared by microwave, solvent evaporation, lyophilization, and hot melt extrusion (HME) techniques and tested for different characterization parameters. The theoretical and in silico parameters suggested that GLB would show good miscibility with the selected carriers under certain conditions. Intermolecular hydrogen bonding between the drug and carrier(s) was confirmed by Fourier transform infrared spectroscopy and proton nuclear magnetic resonance spectroscopy. Solid-state characterizations like powder X-ray diffraction, differential scanning calorimetry, and microscopy confirm the amorphous nature of SDs. The addition of the effervescent agent improved the amorphous nature, due to which the solubility and drug release rate was increased. In vitro and ex vivo intestinal absorption studies showed improved flux and permeability than the pure drug, suggesting an enhanced drug delivery. The GLB solubility, dissolution, and stability were greatly enhanced by the SD and ESD technology.

Recent advances in nanoformulation development of Ritonavir, a key protease inhibitor used in the treatment of HIV-AIDS

INTRODUCTION

AIDS is one of the world's most serious public health challenges. Protease inhibitors are key components of AIDS treatment regimen. Ritonavir is a well-known protease inhibitor with low aqueous solubility belonging to BCS class II category. Some of the severe adverse effects associated with this drug restricted its use in the treatment of AIDS. However, several attempts were made by researchers in the past to enhance the oral bioavailability of Ritonavir.

AREAS COVERED

The current review mainly focuses on the adverse effects of Ritonavir and recent approaches followed by researchers on the development of nanoformulations of Ritonavir. Further, various patents filed on Ritonavir have also been discussed in the current review.

EXPERT OPINION

Most research on nanoformulation development for Ritonavir is mainly focused on enhancing the solubility and oral bioavailability of the drug. Some of the researchers focused on the lymphatic targeting of the drug in order to bypass the hepatic metabolism of the drug. However, most of the research topics did not cover the toxicity evaluation of the developed formulation. Since the major issue of Ritonavir is not only oral bioavailability but also drug-induced toxicity, this area needs to be considered during the formulation development.

Anti-oxidant Containing Nanostructured Lipid Carriers of Ritonavir: Development, Optimization, and In Vitro and In Vivo Evaluations

Acquired immunodeficiency syndrome (AIDS) is a condition caused by the infection of a retrovirus namely, human immunodeficiency virus (HIV). Currently, highly active anti-retroviral therapy (HAART), a combination of anti-viral drugs belonging to different classes is considered to be effective in the management of HIV. Ritonavir, a protease inhibitor (PI), is one of the most important components of the HAART regimen. Because of its lower bioavailability and severe side effects, presently, ritonavir is not being used as a PI. However, this drug is being used as a pharmacokinetic boosting agent for other PIs such as lopinavir and in lower doses. The current study aimed to develop nanostructured lipid carriers (NLCs) encapsulating ritonavir to reduce its side effects and enhance oral bioavailability. Ritonavir-loaded NLCs were developed using a combination of two different solid lipids and liquid lipids. Alpha-tocopherol, a well-known anti-oxidant, was used as an excipient (liquid lipid) in the development of NLCs which were prepared using a simple hot-emulsion and ultrasonication method. Drug-excipient studies were performed using Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC). QbD approach was followed for the screening and optimization of different variables. The developed NLCs were characterized for their particle size (PS), polydispersity index (PDI), zeta potential (ZP), and entrapment efficiency (EE). Furthermore, NLCs were studied for their in vitro drug release profile, and finally, pharmacokinetic parameters were determined using in vivo pharmacokinetic studies. The optimized NLC size was in the range of 273.9 to 458.7 nm, PDI of 0.314 to 0.480, ZP of -52.2 to - 40.9 mV, and EE in the range of 47.37 to 74.51%. From in vitro drug release, it was found that the release of drug in acidic medium was higher than phosphate buffer pH 6.8. Finally, in vivo pharmacokinetic studies revealed a 7-fold enhancement in the area under the curve (AUC) and more than 10-fold higher C_max with the optimized formulation in comparison to pure drug suspension. Graphical Abstract.

Structural exploration of selected C6 and C7-substituted coumarin isomers as selective MAO-B inhibitors

Monoamine Oxidase B is considered a successful target for developing antiparkinsonian drugs. Due to the side effects of current MAO-B inhibitors, there's an urgent need for novel potent and highly selective MAO-B inhibitors. A recent study has shown that coumarins tend to be more selective towards MAO-B than MAO-A when connected to a hex-5-ynyloxy chain at position 6 in contrast to their C7-isomers. The present study describes the mode of interaction of the C6 and C7-substituted coumarin isomers characterized by their difference in selectivity towards MAO-B through molecular docking and molecular dynamics simulations in an effort to elucidate the structural components and molecular interactions that may be responsible for MAO-B selectivity. Three isomeric coumarin pairs connected to ether chain at position 6 or 7 were taken from the literature and modelled according to their IUPAC nomenclature. Molecular docking study revealed one π- π stacking interaction with Tyr-326 in common between the selective coumarin C6-isomers. Resulting complexes of one isomeric coumarin pair that displayed the highest selectivity shift towards MAO-B were subject to 100 ns molecular dynamics simulations study to analyze the stability of the docked complexes. Molecular dynamics revealed that the C7-isomer is relatively stable in both MAO isoforms through the simulation duration, whereas the C6-isomer deemed unstable for MAO-A which may be due to the bulky Phe-208 residue in MAO-A. Our results might be applied for further development and optimization of coumarin derivatives into a successful drug against Parkinson's disease.Communicated by Ramaswamy H. Sarma.

An in-depth analysis of novel combinatorial drug therapy via nanocarriers against HIV/AIDS infection and their clinical perspectives: a systematic review

Introduction: Conventional antiretroviral therapy against HIV infections is threatening to become outdated due to the low chemical, physical, biological, and pharmacokinetic characteristics of therapeutic molecules, followed by the high chance of emergence of drug resistance. Considering the co-encapsulation of multi-infection agents in a single nanocarrier is emerging to offer various benefits such as synergistic action, improved therapeutic efficacy, reduced drug resistance development, patient compliance, and economical therapy.Areas covered: A systematic review of nano-based combinatorial drug therapy was performed using various databases including Scopus, PubMed, Google Scholar, and Science Direct between 2000 and 2020. The search set was screened as per the inclusion and exclusion criteria, followed by 46 scientific articles and seven clinical studies selected for in-depth analysis.Expert opinion: There has been an immense effort to analyze the mechanism of HIV infection to develop a promising therapeutic approach, although the aim of complete prevention has not been succeeded yet. The key finding is to overcome the challenges associated with conventional therapy by the combinatorial drug in a single nanoformulation, which holds great potential for impact in the management of HIV infection.

Hybridized nanoamorphous micellar dispersion using a QbD-DM3 linked rational product design strategy for ritonavir: A BCS IV drug

A QbD-DM³ linked rational product design strategy was adopted to create a hybridized ritonavir (RTV, BCS Class IV) nanoamorphous micellar dispersion (RTV-NAD). A DM³ research strategy was employed in conjunction with the quality-by-design spaces, and quality target product profile to link the critical material attributes and critical process parameters to the quality target product profile's critical product attributes QbD elements. A Box-Behnken design and multivariate analysis using multiple linear regression and partial least squares provided data analysis. The hybridized strategy leveraged three different mechanisms to increase RTV's solubility and four mechanisms to increase its dissolution rate. Statistically significant models were generated for critical product attributes: particle size (p = 0.0000, R² adjusted = 0.9513), polydispersity index (p = 0.0002, R² adjusted = 0.6398), zeta potential (p = 0.0000, R² adjusted = 0.9744), and drug loading on a dry basis (p = 0.0000, R² adjusted = 0.9951). The impact of drug concentration, Soluplus® concentration, and solvent:antisolvent ratio, their interactions and square effects on the critical product attributes were assessed by multivariate analysis. The QbD optimal formulation was determined for RTV-NAD. Multiple linear regression and partial least squares computational predictability was evaluated using three verification batches. The prediction error for critical product attributes was <5%. RTV-NAD and ritonavir microsuspension were characterized by x-ray diffraction and in-vitro dissolution studies. X-ray diffraction confirmed the amorphous nature of the RTV-NAD. RTV-NAD exhibited a 'spring-hover' dissolution profile at pH 4.5. At pH 6.8, a classic 'spring-parachute' dissolution behavior was observed.

Multiple approaches for achieving drug solubility: an in silico perspective

Discovering new therapeutically active molecules is the ultimate destination in pharmaceutical research and development. Most drugs discovered are lipophilic and, hence, exhibit poor aqueous solubility, resulting in low bioavailability. Thus, there is a need to use various solubility enhancement techniques. Computational approaches enable the analysis of drug-carrier interactions or the numerous conformational changes in the carrier matrix that might establish an appropriate balance between cohesive and adhesive stability in a formulation. In this review, we discuss research approaches that provided molecular insight into drugs and their modifiers to unravel their solubility, stability, and bioavailability.