Risk assessment and QbD based optimization of an Eprosartan mesylate nanosuspension: In-vitro characterization, PAMPA and in-vivo assessment

Optimizing rosemary oil nanoemulsion loaded with nelfinavir and epigallocatechin gallate: A Design Expert® endorsed approach for enhanced neuroAIDS management

This study focuses on optimizing the delivery of Nelfinavir (NFV), a vital protease inhibitor in antiretroviral therapy, and Epigallocatechin gallate (EGCG), a potent adjunctive anti- human immunodeficiency virus (anti-HIV) agent found in green tea. The challenge lies in NFV's low intrinsic dissolution rate, significant p-gp efflux, and high hepatic metabolism, necessitating frequent and high-dose administration. Our objective was to develop a nanoemulsion loaded with NFV and EGCG to enhance oral delivery, expediting antiretroviral effects for NeuroAIDS treatment. After meticulous excipient screening, we selected Tween 40 as the surfactant and polyethylene glycol 400 (PEG 400) as the co-surfactant. Employing a Quality by Design (QbD) approach with statistical multivariate methods, we optimized the nanoemulsion that exhibited a droplet size of 83.21 nm, polydispersity index (PDI) of 2.289, transmittance of 95.20 %, zeta potential of 1.495 mV, pH of 6.95, refractive index of 1.40, viscosity of 24.00 ± 0.42 mPas, and conductivity of 0.162 μS/cm. Pharmacokinetic studies demonstrated superior in vivo absorption of the optimized nanoemulsion compared to NFV and EGCG suspension. The optimized nanoemulsion showcased higher Cmax of NFV (9.75 ± 1.23 μg/mL) and EGCG (27.7 ± 1.22 μg/mL) in the brain, along with NFV (26.44 ± 1.44 μg/mL) and EGCG (313.20 ± 5.53 μg/mL) in the plasma. This study advocates for the potential of NFV and EGCG-loaded nanoemulsion in combination antiretroviral therapy (cART) for effective NeuroAIDS management.

High-throughput preparation, scale up and solidification of andrographolide nanosuspension using hummer acoustic resonance technology

The aim of this study was to rapidly develop a sufficiently robust andrographolide nanosuspension (AG-NS) system using hummer acoustic resonance (HAR) technology. The system can effectively improve the dissolution properties of AG, while having high stability and scale-up adaptability. The formulation of AG-NS was optimized in a high-throughput manner using HAR technology and the preparation process was optimized stepwise. Optimal AG-NS with Z-Ave = 223.99 ± 3.16 nm, PDI=0.095 ± 0.007 and zeta potential = -33.20 ± 0.58 mV was successfully prepared with Polyvinylpyrrolidone K30 and Sodium dodecyl sulfate. The optimal prescription was successfully scaled up 100 and 150 times using HAR technology, which was the initial exploration of its commercial scale production. AG-NS was solidified using freeze drying and fluid bed technology, respectively. The optimal AG-NS and its solidified products were exhaustively characterized using various analytical techniques. The high energy input of HAR technology and drying process converted part of the drug into the amorphous state. The in-vitro drug dissolution studies demonstrated relatively higher drug dissolution for AG-NS and its solidified products compared to controls at both the dissolution media (pH 1.2 buffer and pH 6.8 buffer). AG-NS and its solidified products successfully maintained their physical stability in short-term stability and accelerated stability experiments, respectively.

Investigating in-vitro functionality and in-vivo taste assessment of eco-friendly Tadalafil Pastilles

Tadalafil (TDL) has poor bioavailability due to the less aqueous solubility and bitter taste. Oral solid dosage forms, especially tablets, have a broad market worldwide. Constraints of tablets are a long process, pollution, high processing cost, and requiring more excipient. The research was performed to optimize an eco-friendly immediate-acting pastille of TDL to put forward an alternate formulation to a tablet using advanced data mining tools. Another objective is to assess the taste masking of TDL using the Brief Access Taste Aversion (BATA) model. The amount of PEG-4000, Polyox N-10, and Kyron T-314 were chosen as critical material attributes from failure mode effect analysis. Box-Behnken design (BBD) was utilized to optimize the pastilles and ascertained the significant impact of chosen variables on disintegration time and % CDR at 10 min. The control strategy and optimal region were located using an overlay plot. The pastilles were able to release the drug within 15 min due to faster disintegration. The formulated pastilles were of uniform size, shape, and mechanical strength. The bitter taste of TDL was masked and confirmed by the BATA model. The newer formulation may be helpful in the industry due to its eco-friendly, single-step, and economical process. It unlocks a new direction in the field of oral solid dosage form as an alternative to tablets.

Process Optimization of Tinospora cordifolia Extract-Loaded Water in Oil Nanoemulsion Developed by Ultrasound-Assisted Homogenization

Nanoemulsions are gaining interest in a variety of products as a means of integrating easily degradable bioactive compounds, preserving them from oxidation, and increasing their bioavailability. However, preparing stable emulsion compositions with the desired characteristics is a difficult task. The aim of this study was to encapsulate the Tinospora cordifolia aqueous extract (TCAE) into a water in oil (W/O) nanoemulsion and identify its critical process and formulation variables, like oil (27-29.4 mL), the surfactant concentration (0.6-3 mL), and sonication amplitude (40% to 100%), using response surface methodology (RSM). The responses of this formulation were studied with an analysis of the particle size (PS), free fatty acids (FFAs), and encapsulation efficiency (EE). In between, we have studied a fishbone diagram that was used to measure risk and preliminary research. The optimized condition for the formation of a stable nanoemulsion using quality by design was surfactant (2.43 mL), oil concentration (27.61 mL), and sonication amplitude (88.6%), providing a PS of 171.62 nm, FFA content of 0.86 meq/kg oil and viscosity of 0.597 Pa.s for the blank sample compared to the enriched TCAE nanoemulsion with a PS of 243.60 nm, FFA content of 0.27 meq/kg oil and viscosity of 0.22 Pa.s. The EE increases with increasing concentrations of TCAE, from 56.88% to 85.45%. The RSM response demonstrated that both composition variables had a considerable impact on the properties of the W/O nanoemulsion. Furthermore, after the storage time, the enriched TCAE nanoemulsion showed better stability over the blank nanoemulsion, specially the FFAs, and the blank increased from 0.142 to 1.22 meq/kg oil, while TCAE showed 0.266 to 0.82 meq/kg.

Quality by design (QbD) approach-based development of optimized nanocarrier to achieve quality target product profile (QTPP)-targeted lymphatic delivery

Background.Insulin, commonly used for diabetes treatment, needs better ways to improve its effectiveness and safety due to its challenges with poor permeability and stability. Various system has been developed for oral peptide delivery. The non-targeted system can prevent gastric and enzymatic degradation of peptides but cannot increase the bulk transport of peptides across the membrane. However, the non-selectivity is the limitation of the existing system. Numerous carbohydrate-binding receptors overexpressed on intestinal macrophage cells (M-cells) of gut-associated lymphoid tissue. It is the most desirable site for receptor-mediated endocytosis and lymphatic drug delivery of peptides.Objective. The prime objective of the study was to fabricate mannose ligand conjugated nanoparticles (MNPs) employing a quality-by-design approach to address permeability challenges after oral administration. Herein, the study's secondary objective of this study is to identify the influencing factor for producing quality products. Considering this objective, the Lymphatic uptake of NPs was selected as a quality target product profile (QTPP), and a systematic study was conducted to identify the critical formulation attributes (CFAs) and critical process parameters (CPP) influencing critical quality attributes (CQAs). Mannosylated Chitosan concentrations (MCs) and TPP concentrations were identified as CFAs, and stirring speed was identified as CPP.Methods. MNPs were prepared by the inotropic gelation method and filled into the enteric-coated capsule to protect from acidic environments. The effect of CFAs and CPP on responses like particle size (X) and entrapment (Y) was observed by Box-Behnken design (BBD). ANOVA statistically evaluated the result to confirm a significant level (p< 0.05). The optimal conditions of NPs were obtained by constructing an overlay plot and determining the desirability value. HPLC and zeta-seizer analysis characterized the lyophilized NPs. Cell-line studies were performed to confirm the safety and M-cell targeting of NPs to enhance Insulin oral bioavailability.Results. The morphology of NPs was revealed by SEM. The developed NPs showed a nearly oval shape with the average size, surface potential, and % drug entrapment were 245.52 ± 3.37 nm, 22.12 ± 2.13 mV, and 76.15 ± 1.3%, respectively. MTT assay result exhibited that MNPs safe and Confocal imaging inference that NPs selectively uptake by the M-cell.Conclusion. BBD experimental design enables the effective formulation of optimized NPs. The statistical analysis estimated a clear assessment of the significance of the process and formulation variable. Cell line study confirms that NPs are safe and effectively uptake by the cell.

A quality by design framework for developing nanocrystal bioenabling formulations

The present study aims to outline a rational framework for the design and development of a 1.0% (w/v) hydrocortisone nanocrystal-based formulation, resorting to a simple, efficient, and scalable nanonization methodology, based on the high-pressure homogenization (HPH) technique. Accordingly, the innovative product was comprehensively optimized following a Quality by Design (QbD) approach. The thorough selection of formulation composition was driven by a dual purpose: improving skin permeation and stability. In the early stage of development, a Failure Mode, Effects and Criticality Analysis (FMECA) diagram was employed to identify the most impactful variables for the critical quality attributes (CQAs). In this sense, a rotatable, three-factor and five-level circumscribed central composite design (CCCD) was applied to investigate how squalene concentration (x1), soluplus concentration (x2) and HPH-time (x3) influence physicochemical properties, performance and physical stability of the formulation. A robust Design Space (DS) was defined, establishing the optimal settings for the critical variables, whose combination meets the requirements set in the quality target product profile (QTPP). Morphological analysis revealed the cuboidal shape of hydrocortisone nanocrystals. In what concerns colloidal properties, the most promising formulation disclosed a small particle size (Dx(50) = 311.8 ± 1.5 nm), along with narrow size distribution (span value = 1.91 ± 0.17). Zeta potential results (-2.19 ± 0.15 mV--12.1 ± 0.4 mV) suggested a steric hindrance stabilization. FTIR spectra showed no chemical interactions between drug and formulation components. XRD diffractograms confirmed loss of crystallinity during the downsizing process. In vitro studies revealed an improvement on drug release rate (316 ± 21-516 ± 35 μg/cm2/√t), compared to the coarse suspension and commercial products, and a straight dependence on the stabilizer concentration and HPH time. The permeation flux across the skin (0.16 ± 0.02-1.2 ± 0.5 μg/cm2/h) appeared to be dependent on the drug physicochemical properties, in particular saturation solubility. Further characterization of the experimental formulations pointed out the role of the stabilizing component to prevent against physical instability phenomena. This organic solvent-free, and therefore "green" nanocrystal production technology offers great potential for pharmaceutical R&D and drug delivery by enabling the development of new forms of conventional drugs with optimal physicochemical properties and performance.

Systematic Screening Study for the Selection of Proper Stabilizers to Produce Physically Stable Canagliflozin Nanosuspension by Wet Milling Method

One of the crucial approaches to managing the low solubility and weak bioavailability of drugs is via nanocrystal technology. Through this technology, drug particles have an increased solubility and a faster dissolution rate due to high surface free energy, which requires an appropriate stabilizer(s) to prevent instabilities during the manufacturing process and storage of the nanosuspension. This study aimed to establish a scientific predictive system for properly selecting stabilizers or to reduce the attempts on a trial-and-error basis in the wet-milling method. In total, 42 experiments were performed to examine the effect of critical material attributes on the wettability of the drug, the saturation solubility in the stabilizer solutions or combinations thereof and the dynamic viscosity of stabilizer solutions. All data were evaluated by Minitab 19® and an optimization study was performed. The optimized formulation at a certain concentration of stabilizer combination was ground by Dyno Mill® with 0.3 mm beads for one hour. The optimized nanosuspension with a particle size of 204.5 nm was obtained in short milling time and offered 3.05- and 3.51 times better dissolution rates than the marketed drug product (Invokana® 100 mg) in pH 4.5 and pH 6.8 as non-sink conditions, respectively. The formulation was monitored for three months at room temperature and 4 °C. The parameters were 261.30 nm, 0.163, -14.1 mV and 261.50 nm, 0.216 and -17.8 mV, respectively. It was concluded that this approach might indicate the appropriate selection of stabilizers for the wet-milling process.

Quality-by-Design-Assisted Optimization of Carvacrol Oil-Loaded Niosomal Gel for Anti-Inflammatory Efficacy by Topical Route

Niosomes are multilamellar vesicles that effectively transfer active ingredients into the skin's layers. To improve the active substance's penetration across the skin, these carriers are frequently utilized as topical drug delivery systems. Essential oils (EOs) have garnered significant interest in the field of research and development owing to their various pharmacological activities, cost-effectiveness, and simple manufacturing techniques. However, these ingredients undergo degradation and oxidation over time, leading to a loss of functionality. Niosome formulations have been developed to deal with these challenges. The main goal of this work was to create a niosomal gel of carvacrol oil (CVC) to improve its penetration into the skin for anti-inflammatory actions and stability. By changing the ratio of drug, cholesterol and surfactant, various formulations of CVC niosomes were formulated using Box Behnken Design (BBD). A thin-film hydration technique using a rotary evaporator was employed for the development of niosomes. Following optimization, the CVC-loaded niosomes had shown: 180.23 nm, 0.265, -31.70 mV, and 90.61% of vesicle size, PDI, zeta potential, and EE%. An in vitro study on drug release discovered the rates of drug release for CVC-Ns and CVC suspension, which were found to be 70.24 ± 1.21 and 32.87 ± 1.03, respectively. The release of CVC from niosomes best fit the Higuchi model, and the Korsmeyer-Peppas model suggests that the release of the drug followed the non-Fickian diffusion. In a dermatokinetic investigation, niosome gel significantly increased CVC transport in the skin layers when compared to CVC-conventional formulation gel (CVC-CFG). Confocal laser scanning microscopy (CLSM) of rat skin exposed to the rhodamine B-loaded niosome formulation showed a deeper penetration of 25.0 µm compared to the hydroalcoholic rhodamine B solution (5.0 µm). Additionally, the CVC-N gel antioxidant activity was higher than that of free CVC. The formulation coded F4 was selected as the optimized formulation and then gelled with carbopol to improve its topical application. Niosomal gel underwent tests for pH determination, spreadability, texture analysis, and CLSM. Our findings imply that the niosomal gel formulations could represent a potential strategy for the topical delivery of CVC in the treatment of inflammatory disease.

Quality-by-design based fabrication of febuxostat-loaded nanoemulsion: Statistical optimization, characterizations, permeability, and bioavailability studies

The present work deals with QbD-based development of FEB-loaded nanoemulsion (FEB-NE) in order to enhance bioavailability and permeability. In the beginning, the risk assessment was performed on different experimental variables using the Ishikawa diagram followed by FMEA study in order to find critical process parameter (CPP) and critical material attributes (CMAs). To build quality in nanoemulsion, the quality target product profiles (QTPP) and critical quality attributes (CQAs) were determined. The different batches of FEB-NE were produced by the microemulsification-probe sonication method. Effect of varying levels of independent variables such as oil concentration (X₁), S_mix concentration (X₃), and amplitude (X₃) on responses such as globule size (Y₁), zeta potential (Y₂), and entrapment efficiency (Y₃) were studied using Box-Behnken design (BDD). FEB-NE formulation was optimized using a graphical and numerical method. The optimized formulation concentrations and their responses (CQAs) were located as design space in an overlay plot. The spherical shapes of globules were visualized by surface morphology using AFM and TEM. In vitro dissolution study showed 93.32% drug release from the optimized FEB-NE formulation. The drug release mechanism followed by the formulation was the Higuchi-matrix kinetics with a regression coefficient of 0.9236 (R²). FEB-NE showed enhanced permeability using PAMPA (artificial non-cell membrane) and everted gut sac model method. The developed optimized FEB-NE exhibited the enhancement of bioavailability by 2.48 fold as compared to FEB-suspension using Wistar rats suggesting improvement of solubility of a lipophilic drug. The optimized batch remained stable for 90 days at 4 °C and 25 °C. Thus, QbD-based development of FEB-NE can be useful for a better perspective on a commercial scale.

Design and biological evaluation of Repaglinide loaded polymeric nanocarriers for diabetes linked neurodegenerative disorder: QbD-driven optimization, in situ, in vitro and in vivo investigation

Diabetes mellitus is a metabolic disorder characterized by inadequate insulin secretion and signaling dysfunction, leading to a vast spectrum of systemic complications. These complications trigger cascades of events that result in amyloid-beta plaque formation and lead to neurodegenerative disorders such as Alzheimer's. Repaglinide (REP) an insulinotropic agent, suppresses the down regulatory element antagonist modulator (DREAM) and enhances the ATF6 expression to provide neuroprotection following the DREAM/ATF6/apoptotic pathway. However, oral administration of REP for brain delivery becomes more complicated due to its physicochemical characteristics (high protein binding (>98%), low permeability, short half-life (∼1 h), low bioavailability). Therefore, to circumvent these problems, we develop a polymeric nanocarrier system (PNPs) by in-house synthesized di-block copolymer (PEG-PCL). PNPs were optimized using quality by design approach response surface methodology and characterized by particle size (112.53 ± 5.91 nm), PDI (0.157 ± 0.08), and zeta potential (-6.20 ± 0.82 mV). In vitro release study revealed that PNPs (∼70% in 48 h) followed the Korsmeyer-Peppas model with a Fickian diffusion release pattern, and in intestinal absorption assay PNPs showed increment of ∼1.3 folds compared of REP. Moreover, cellular studies confirmed that REP-loaded PNPs significantly enhance the cellular viability, uptake and reduce the peroxide-induced stress in neuroblastoma SHSY-5Y cells. Further, pharmacokinetic parameters of PNPs showed an increment in t_max (2.46-fold), and C_max (1.25-fold) associated with REP. In the brain biodistribution study, REP loaded PNPs was sustained for 24 h whereas free REP sustained only for12 h. In DM induced neurodegenerative murine model, a significantly (p < 0.01) enhanced pharmacodynamic was observed in PNP treated group by estimating biochemical and behavioral parameters. Hence, oral administration of REP-loaded PNPs promotes efficient brain uptake and improved efficacy of REP in the diseased model.

Elaborating the crystal transformation referenced microhydrodynamic model and fracture mechanism combined molecular modelling of irbesartan nanosuspensions formation in wet media milling

In recent years, polymorphic transformation involved in media milling has become a key factor in inducing the instability of nanosuspensions (NSs). The variation trend of microhydrodynamic parameters, including milling intensity factor (F), can be observed under different milling conditions. Therefore, this study first referenced the microhydrodynamic model to explore how formulations and process parameters affect Irbesartan (IRB) form A crystallinity during wet media milling. As a result, the crystallinity of form A was affected by the intermolecular interactions between drug particles and stabilizers. The crystallinity of form A decreased with decreasing drug loading, increasing stirrer speed and bead loading, which depended on the role of F. Milling could promote the transformation from a 1H to 2H tetrazole ring with stabilizers containing -OH, and form B was changed to form A and finally to an amorphous state. Molecular modelling shows that forms A and B are ductile and fragile materials, respectively, and both present anisotropy. When milling beads hit both polymorphs paralleling to the (010) surface, the bead-bead collisions are more helpful in fracturing IRB particles. The results of this study may provide a foundation for controlling crystal transformation and obtaining ideal crystal forms.

Quality by Design (QbD) Approach for a Nanoparticulate Imiquimod Formulation as an Investigational Medicinal Product

The present article exemplifies the application of the concept of quality by design (QbD) for the systematic development of a nanoparticulate imiquimod (IMQ) emulsion gel formulation as an investigational medicinal product (IMP) for evaluation in an academic phase-I/II clinical trial for the treatment of actinic keratosis (AK) against the comparator Aldara (EudraCT: 2015-002203-28). The design of the QbD elements of a quality target product profile (QTPP) enables the identification of the critical quality attributes (CQAs) of the drug product as the content of IMQ, the particle-size distribution, the pH, the rheological properties, the permeation rate and the chemical, physical and microbiological stability. Critical material attributes (CMAs) and critical process parameters (CPPs) are identified by using a risk-based approach in an Ishikawa diagram and in a risk-estimation matrix. In this study, the identified CPPs of the wet media ball-milling process's milling time and milling speed are evaluated in a central composite design of experiments (DoEs) approach, revealing criticality for both factors for the resulting mean particle size, while only the milling time is significantly affecting the polydispersity. To achieve a mean particle size in the range of 300-400 nm with a minimal PdI, the optimal process conditions are found to be 650 rpm for 135 min. Validating the model reveals a good correlation between the predicted and observed values. Adequate control strategies were implemented for intermediate products as in-process controls (IPCs) and quality control (QC) tests of the identified CQAs. The IPC and QC data from 13 "IMI-Gel" batches manufactured in adherence to good manufacturing practice (GMP) reveal consistent quality with minimal batch-to-batch variability.

Ritonavir nanosuspensions prepared by microfluidization with enhanced solubility and desirable immunological properties

The objective of this study was to develop ritonavir (RTV) nanosuspensions (NSs) by microfluidization method. Particle size (PS) measurements were performed by photon correlation spectroscopy. Amorphous properties of the particles were evaluated by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The dissolution studies were conducted in fed state simulated intestinal fluid (FeSSIF) medium. The flow cytometry was utilized to determine the lymphocyte sub-groups and immune response of NSs. RTV NSs were obtained with 400-500 nm PS. The crystal properties of RTV remain unchanged. The solubility of NS was enhanced five times. 57% and 18% of RTV were dissolved in FeSSIF medium for NSs and coarse powder. According to immunological studies, the prepared NSs did not significantly alter the ratio of CD4⁺/CD8⁺. Therefore, NSs may be a beneficial approach for the oral administration of RTV.

Solid Self-Nano Emulsifying Nanoplatform Loaded with Tamoxifen and Resveratrol for Treatment of Breast Cancer

The solid self-nanoemulsifying drug delivery system (s-SNEDDS) is a growing platform for the delivery of drugs via oral route. In the present work, tamoxifen (TAM) was loaded in SNEDDS with resveratrol (RES), which is a potent chemotherapeutic, antioxidant, anti-inflammatory and P-gp inhibitor for enhancing bioavailability and to obtain synergistic anti-cancer effect against breast cancer. SNEDDS were developed using capmul MCM as oil, Tween 80 as surfactant and transcutol-HP as co-surfactant and optimized by central composite rotatable design. Neusilin US2 concentration was optimized for adsorption of liquid SNEDDS to prepare s-SNEDDS. The developed formulation was characterized and investigated for various in vitro and cell line comparative studies. Optimized TAM-RES-s-SNEDDS showed spherical droplets of a size less than 200 nm. In all in vitro studies, TAM-RES-s-SNEDDS showed significantly improved (p ˂ 0.05) release and permeation across the dialysis membrane and intestinal lumen. Moreover, TAM-RES-s-SNEDDS possessed significantly greater therapeutic efficacy (p < 0.05) and better internalization on the MCF-7 cell line as compared to the conventional formulation. Additionally, oral bioavailability of TAM from SNEDDS was 1.63 folds significantly higher (p < 0.05) than that of combination suspension and 4.16 folds significantly higher (p < 0.05) than TAM suspension. Thus, findings suggest that TAM- RES-s-SNEDDS can be the future delivery system that potentially delivers both drugs to cancer cells for better treatment.

Formulation and characterization of eprosartan mesylate and β-cyclodextrin inclusion complex prepared by microwave technology

The goal of this work was to improve the aqueous solubility and dissolution rate of eprosartan mesylate by preparing inclusion complex of drug with β-cyclodextrin (β-CD) by microwave technique. In order to determine the solubility of eprosartan, phase solubility was determined and dissolution study was also conducted. Further, analytical techniques for instance, particle size distribution, differential scanning calorimetry, powder X-ray diffraction, scanning electron microscopy, Fourier-transform infrared spectroscopy, and nuclear magnetic resonance spectroscopy were used for the characterization of inclusion complex. In addition, the binding pattern of eprosartan with the β-CD was investigated by molecular modeling study. Phase solubility study revealed that approximately 4.48 folds improvement in the solubility of drug was noted with β-CD (10 mM). The estimated stability constant (K_c) values for eprosartan:β-CD binary mixture was found to be 280.78 M^–1. The prepared inclusion complex of drug with β-CD presented better drug release profile (62.96 ± 2.01% in 1 h) as compared to their physical mixture (41.41 ± 1.77% in 1 h) or drug per se (29.97 ± 3.13%). The inclusion complex demonstrated different features and properties from pure drug, and we inferred that this could be due to the inclusion of drug into cyclodextrin cavity that confirmed by different analytical method. Molecular modeling study demonstrated a good affinity of eprosartan to entangle to β-CD. The outcomes have shown that guest molecule has many significant interactions with the host molecule. These observations are very interesting and may be a valuable approach to improve the solubility and in turn the bioavailability of eprosartan.

Excipient-free nanodispersions dominated by amphiphilic glycosides for bioavailability enhancement of hydrophobic aglycones, a case of glycyrrhetinic acid with diammonium glycyrrhizinate

Natural aglycones, a major ingredient accompanied by glycosides in plants, have played an important role in the treatment of various diseases. However, their bioavailability is limited by their poor water solubility. In contrast to previous efforts that required the use of new exotic materials which may raise concerns about biocompatibility, we report the first case of excipient-free nanodispersions in which an insoluble glycyrrhetinic acid (GA) assembled with its amphiphilic parent drug diammonium glycyrrhizinate (DG) into water-dispersible nanodispersions (130.8 nm for particle size and 91.74% for encapsulation efficiency). This strategy largely increased GA's water apparent solubility by hundreds of times to 549.0 μg/mL with a high cumulative dissolution percentage in vitro greater than 80% in 5 min. The study on the formation mechanism showed that the OH, C-O and C=O group stretching peaks shifted in the FTIR spectra of GA-DG nanodispersions, while the COOH peak (δ _COOH 12.19 ppm) disappeared in the ¹H NMR spectrum of GA-DG nanodispersions, indicating that carboxyl groups on GA may interact with the hydroxyl groups of DG in solution. Molecular dynamics simulations suggested that both hydrophobic interactions and hydrogen-bond interactions contribute to the coassembly of GA and DG molecules in aqueous solution. Oral pharmacokinetic studies in rats demonstrated that such nanodispersions have a significant increase in C_max and AUC_0-t of 2.45- and 3.45-fold compared with those for GA, respectively. Therefore, this strategy, employing amphiphilic glycosides as excipients to prepare nanodispersions, not using new materials, paves the way for the further application of hydrophobic aglycone drugs.

Exploring the influence factors and improvement strategies of drug polymorphic transformation combined kinetic and thermodynamic perspectives during the formation of nanosuspensions

Nanosuspensions can effectively increase saturation solubility and improve the bioavailability of poorly water-soluble drugs attributed to high loading and surface-to-volume ratio. Wet media milling has been regarded as a scalable method to prepare nanosuspensions because of its simple operation and easy scale-up. In recent years, besides particle aggregation and Ostwald ripening, polymorphic transformation induced by processing has become a critical factor leading to the instability of nanosuspensions. Therefore, this review aims to discuss the influence factors comprehensively and put forward the corresponding improvement strategies of polymorphic transformation during the formation of nanosuspensions. In addition, this review also demonstrates the implication of molecular simulation in polymorphic transformation. The competition between shear-induced amorphization and thermally activated crystallization is the global mechanism of polymorphic transformation during media milling. The factors affecting the polymorphic transformation and corresponding improvement strategies are summarized from formulation and process parameters perspectives during the formation of nanosuspensions. The development of analytical techniques has promoted the qualitative and quantitative characterization of polymorphic transformation, and some techniques can in-situ monitor dynamic transformation. The microhydrodynamic model can be referenced to study the stress intensities by analyzing formulation and process parameters during wet media milling. Molecular simulation can be used to explore the possible polymorphic transformation based on the crystal structure and energy. This review is helpful to improve the stability of nanosuspensions by regulating polymorphic transformation, providing quality assurance for nanosuspension-based products.

Multi-directionally evaluating the formation mechanism of 1,4-dihydropyridine drug nanosuspensions through experimental validation and computer-aided drug design

The poor aqueous solubility of 1,4-dihydropyridine drugs needs to be solved urgently to improve the bioavailability. Nanotechnology can improve drug solubility and dissolution by reducing particle size, but usually a specific polymer or surfactant is required for stabilization. In this study, Poloxamer-407(P-407) was screened as the optimal stabilize through energy simulation, molecular docking and particle size. morphological study, X-ray diffraction, differential scanning calorimetry, Fourier transform infrared spectroscopy, Raman, in vitro dissolution test and molecular simulation of interactions were utilized to explore the formation mechanisms of four 1,4-dihydropyridine drugs/P-407 nanosuspensions. The result shows that the optimized nanosuspensions had the particle size in the nano-size range and maintained the original crystal state. The in vitro dissolution rate of the nanosuspension was 3-4 times higher than the corresponding API and could reduce the restriction of drug dissolution in different pH environments. Raman spectroscopy, FTIR and molecular docking simulations provided strong supporting evidence for the formation mechanism of 1,4-dihydropyridine drugs/P-407 nanosuspensions at the molecular level, which confirmed that the stable intermolecular hydrogen bond adsorption and hydrophobic interaction were formed between the drug and P-407. This research will provide practical concepts and technologies, which are helpful to develop nanosuspensions for the same class of drugs.

Development of cyclosporine A nanosuspension: cytotoxicity and permeability on Caco-2 cell lines

Cyclosporine A is a calcineurin inhibitor and is usually used as an immunosuppressant medication. The main purpose of this study is to develop nanosuspension of polypeptide cyclosporine A by using the wet milling method for oral administration. Cell culture studies were also performed with human intestinal Caco-2 cell lines. Hydroxypropyl methylcellulose and sodium dodecyl sulfate were used as stabilizers in nanosuspension. In vitro characterization studies such as Fourier-transform infrared analysis and morphological imaging with scanning electron microscopy have been carried out with obtained cyclosporine A nanosuspension. The particle size, particle size distribution, and zeta potential values of the nanosuspension were measured approximately 400 nm, 0.4, and -25 mV, respectively. The solubility of cyclosporine A was increased 4.5 times in nanosuspension compared to the coarse cyclosporine A powder. As a result of cytotoxicity studies conducted with different concentrations, it was decided to conduct permeability studies at a dose equivalent to 150 µg/mL cyclosporine A. Permeation studies have shown that the nanosuspension increases cyclosporine A transport by 5 and 1.5 times, respectively, compared to coarse powder and commercial product.

Best practices in current models mimicking drug permeability in the gastrointestinal tract - an UNGAP review

The absorption of orally administered drug products is a complex, dynamic process, dependent on a range of biopharmaceutical properties; notably the aqueous solubility of a molecule, stability within the gastrointestinal tract (GIT) and permeability. From a regulatory perspective, the concept of high intestinal permeability is intrinsically linked to the fraction of the oral dose absorbed. The relationship between permeability and the extent of absorption means that experimental models of permeability have regularly been used as a surrogate measure to estimate the fraction absorbed. Accurate assessment of a molecule's intestinal permeability is of critical importance during the pharmaceutical development process of oral drug products, and the current review provides a critique of in vivo, in vitro and ex vivo approaches. The usefulness of in silico models to predict drug permeability is also discussed and an overview of solvent systems used in permeability assessments is provided. Studies of drug absorption in humans are an indirect indicator of intestinal permeability, but in vitro and ex vivo tools provide initial screening approaches are important tools for direct assessment of permeability in drug development. Continued refinement of the accuracy of in silico approaches and their validation with human in vivo data will facilitate more efficient characterisation of permeability earlier in the drug development process and will provide useful inputs for integrated, end-to-end absorption modelling.

Increase in Dissolution Rate of Zotepine via Nanomilling Process - Impact of Dried Nanocrystalline Suspensions on Bioavailability

Zotepine is an atypical antipsychotic drug used in the treatment of schizophrenia. However, its poor dissolution properties limit its therapeutic efficacy. In this investigation, a series of nanosuspension-containing zotepine were prepared employing media milling method with an aim to improve its dissolution properties and oral bioavailability. Briefly, Box-Behnken design was applied to investigate the influence of various independent variables such as X₁- amount of stabilizer, X₂- amount of milling agent, and X₃- milling time on the performance of the formulation. Dissolution studies revealed enhancement of dissolution rate as compared to pure drug. Solid state characterization (DSC, PXRD, and SEM) studies demonstrated no polymorphic changes in drug after lyophilization of media-milled nanosuspension. In vivo pharmacokinetic studies of lyophilized nanosuspension was carried out in rat and the results exhibited significant improvement in C_max and AUC_0-t, about 450.0 and 287.45%, respectively, suggesting amelioration in oral bioavailability by 2.87-fold higher as compared to pure drug. Accelerated stability studies of the optimized lyophilized formulation at 40°C and 75% RH suggested stability of the nanocrystals for at least a 6-month period. The obtained nanocrystals successfully showed dissolution enhancement and improved oral bioavailability of poorly water-soluble drug, zotepine.

Development of ritonavir-loaded nanostructured lipid carriers employing quality by design (QbD) as a tool: characterizations, permeability, and bioavailability studies

The objective of the present work was to optimize ritonavir (RTV)-loaded nanostructured lipid carriers (NLCs) to improve bioavailability using a quality by design (QbD)-based technique. Risk assessment was studied using "cause and effect" diagram followed by failure mode effect analysis (FMEA) to identify the effective high-risk variables for the formulation development. Quality target product profile (QTPP) and critical quality attributes (CQAs) were initially assigned for the proposed product. Central composite rotatable design (CCRD) was used to identify the individual and combined interactions of formulation variables. RTV-loaded NLC (RTV-NLC) was prepared using emulsification-ultrasonication method. The effect of formulation variables like ultrasound amplitude, lipid concentration, surfactant concentration on their responses like particle size, polydispersity index (PDI), and entrapment efficiency (EE) were studied by CCRD. The optimized formulation was subjected to lyophilization to obtain dry NLCs for solid-state analysis. DSC and PXRD investigations showed that RTV was molecularly dispersed in lipid matrix indicating amorphous form present in the formulation. FESEM and AFM depicted the spherical and uniform particles. The increase in solubility and dissolution rate is expected to be related to the molecular dispersion, amorphous state, of the drug in the nanoparticle. The optimized NLCs showed good physical stability during storage for 6 months. RTV-NLC was further subjected to in vitro studies and found a successful sustained release rate of 92.37 ± 1.03%. The parallel artificial membrane permeability assay (PAMPA) and everted gut sac model have demonstrated the permeation enhancement of RTV. In vivo study observed the enhanced bioavailability with 2.86-fold suggesting optimized NLC successfully overcome the issue of solubility.

Improved transdermal permeability of tanshinone IIA from cataplasms by loading onto nanocrystals and porous silica

Novel transdermal cataplasms have been designed to improve permeability of poorly soluble drugs by different pretreatments. Nanocrystal and porous silica solid dispersions were loaded with Tanshinone IIA and incorporated into a cross-linked hydrogel matrix of cataplasm. It was shown that the small particle size and improved dissolution would increase dermal bioavailability. The adhesion, rheological properties, drug release, skin permeation, skin deposition and in vivo skin absorption of the different formulations were investigated. In an in vitro experiment using mouse skin, cumulative amount of drug permeated within 24 h was 7.32 ± 0.98 μg/cm² from conventional cataplasm, 13.14 ± 0.70 μg/cm² from nanocrystal-loaded cataplasm and 11.40 ± 0.13 μg/cm² from porous silica solid dispersion-loaded cataplasm. In vitro dissolution profiles showed that drug release was 76.5% and 74.9% from two optimized cataplasms within 24 h, while conventional cataplasm was 55.0%. The cross-linking characteristics of the cataplasms were preserved after incorporation of different drug forms, while the elastic and viscous behaviors of the hydrogel layers increased. In vivo evaluation by CLSM showed the more favorable skin permeation for two optimized cataplasms. These findings suggest that applications of nanocrystal and porous silica systems on cataplasms enable effective transdermal delivery of poorly soluble drugs. The resulting drug delivery and rheological properties are desirable for transdermal application.AbbreviationAll the abbreviations that appear in this article are shown in Table 1.

Non-Ionic Surfactants for Stabilization of Polymeric Nanoparticles for Biomedical Uses

Surfactants are essential in the manufacture of polymeric nanoparticles by emulsion formation methods and to preserve the stability of carriers in liquid media. The deposition of non-ionic surfactants at the interface allows a considerable reduction of the globule of the emulsion with high biocompatibility and the possibility of oscillating the final sizes in a wide nanometric range. Therefore, this review presents an analysis of the three principal non-ionic surfactants utilized in the manufacture of polymeric nanoparticles; polysorbates, poly(vinyl alcohol), and poloxamers. We included a section on general properties and uses and a comprehensive compilation of formulations with each principal non-ionic surfactant. Then, we highlight a section on the interaction of non-ionic surfactants with biological barriers to emphasize that the function of surfactants is not limited to stabilizing the dispersion of nanoparticles and has a broad impact on pharmacokinetics. Finally, the last section corresponds to a recommendation in the experimental approach for choosing a surfactant applying the systematic methodology of Quality by Design.

Quality by design (QbD)-based fabrication of atazanavir-loaded nanostructured lipid carriers for lymph targeting: bioavailability enhancement using chylomicron flow block model and toxicity studies

Atazanavir (ATV) is widely used as anti-HIV agent having poor aqueous solubility needs to modulate novel drug delivery system to enhance therapeutic efficiency and safety. The main objective of the present work was to fabricate ATV-loaded nanostructured lipid carriers (NLCs) employing quality by design (QbD) approach to address the challenges of bioavailability and their safety after oral administration. Herein, the main objective was to identify the influencing variables for the production of quality products. Considering this objective, quality target product profile (QTPP) was assigned and a systematic risk assessment study was performed to identify the critical material attributes (CMAs) and critical process parameter (CPP) having an influence on critical quality attributes (CQAs). Lipid concentrations, surfactant concentrations, and pressure of high-pressure homogenizer were identified as CMAs and CPP. ATV-NLCs were prepared by emulsification-high pressure homogenization method and further lyophilized to obtain solid-state NLCs. The effect of formulation variables (CMAs and CPP) on responses like particle size (Y₁), polydispersity index (Y₂), and zeta potential (Y₃) was observed by central composite rotatable design (CCRD). The data were statistically evaluated by ANOVA for confirmation of a significant level (p < 0.05). The optimal conditions of NLCs were obtained by generating design space and desirability value. The lyophilized ATV-NLCs were characterized by DSC, powder X-ray diffraction, and FT-IR analysis. The morphology of NLCs was revealed by TEM and FESEM. In vitro study suggested a sustained release pattern of drug (92.37 ± 1.03%) with a mechanism of Korsmeyer-Peppas model (r² = 0.925, and n = 0.63). In vivo evaluation in Wistar rats showed significantly higher (p < 0.001) plasma drug concentration of ATV-NLCs as compared to ATV-suspension using chylomicron flow block model. The relative bioavailability of ATV-NLCs was obtained to be 2.54 folds. Thus, a safe and promising drug targeting system was successfully developed to improve bioavailability and avoiding first-pass effect ensures to circumvent the acute-toxicity of liver.

Development of a Curcumin-Loaded Polymeric Microparticulate Oral Drug Delivery System for Colon Targeting by Quality-by-Design Approach

The purpose of this study was to apply the quality-by-design (QbD) approach for the development of colon-targeted curcumin-loaded polymeric microparticles (Col-CUR-MPs). The proportion of the enterosoluble polymer (Eudragit^® FS) in the polymeric matrix, curcumin concentration, and the concentration of the polymer mixture (Eudragit^® FS-polycaprolactone) were identified as potential risk factors for the quality of the final product following risk assessment. The influence of these variables on the critical quality attributes (CQAs) of Col-CUR-MPs was investigated. Therefore, a central composite face experimental design was used in order to determine the functional relationships between variables and product CQAs. The obtained regression model and contour plots were used to establish the design space. Finally, the model was validated by preparing two microparticulate formulations, one corresponding to the robust setpoint from within the design space and one outside the established design space, and calculating the percentage bias between the experimental and predicted values. The in vivo study, which was conducted on a fluorescein-loaded formulation that corresponded to the robust setpoint determined by QbD and that contained a mixture of polycaprolactone and Eudragit^® FS (60:40, w/w), confirmed the colon-targeting qualities of this formulation.

Optimization and Evaluation of Poly(lactide-co-glycolide) Nanoparticles for Enhanced Cellular Uptake and Efficacy of Paclitaxel in the Treatment of Head and Neck Cancer

The particle size (PS) and encapsulation efficiency (EE%) of drug-loaded nanoparticles (NPs) may inhibit their cellular uptake and lead to possible leakage of the drug into the systemic circulation at the tumor site. In this work, ultra-high paclitaxel-loaded poly(lactide-co-glycolide) NPs (PTX-PLGA-NPs) with ultra-small sizes were prepared and optimized by adopting the principles of quality by design (QbD) approach. The optimized PTX-PLGA-NPs showed ultra-small spherical particles of about 53 nm with EE% exceeding 90%, a relatively low polydispersity index (PDI) of 0.221, an effective surface charge of -10.1 mV, and a 10-fold increase in the in vitro drug release over 72 h relative to free drug. The cellular viability of pharynx carcinoma cells decreased by almost 50% in 24 h following treatment with optimized PTX-PLGA-NPs, compared to only 20% from the free drug. The intracellular uptake of PTX-PLGA-NPs was highly favored, and the antitumor activity of PTX was remarkably improved with a reduction in its half maximal inhibitory concentration (IC50), by almost 50% relative to free drug solution. These results suggest that the optimal critical formulation parameters, guided by QbD principles, could produce PLGA-NPs with remarkably high EE% and ultra-small PS, resulting in enhanced cellular uptake and efficacy of PTX.

Development and Evaluation of Docetaxel-Phospholipid Complex Loaded Self-Microemulsifying Drug Delivery System: Optimization and In Vitro/Ex Vivo Studies

Docetaxel (DTX) has clinical efficacy in the treatment of breast cancer, but it is difficult to develop a product for oral administration, due to low solubility and permeability. This study focused on preparing a self-microemulsifying drug delivery system (SME) loaded with DTX-phospholipid complex (DTX@PLC), to improve the dissolution and gastrointestinal (GI) permeability of DTX. A dual technique combining the phospholipid complexation and SME formulation described as improving upon the disadvantages of DTX has been proposed. We hypothesized that the complexation of DTX with phospholipids can improve the lipophilicity of DTX, thereby increasing the affinity of the drug to the cell lipid membrane, and simultaneously improving permeability through the GI barrier. Meanwhile, DTX@PLC-loaded SME (DTX@PLC-SME) increases the dissolution and surface area of DTX by forming a microemulsion in the intestinal fluid, providing sufficient opportunity for the drug to contact the GI membrane. First, we prepared DTX@PLC-SME by combining dual technologies, which are advantages for oral absorption. Next, we optimized DTX@PLC-SME with nanosized droplets (117.1 nm), low precipitation (8.9%), and high solubility (33.0 mg/g), which formed a homogeneous microemulsion in the aqueous phase. Dissolution and cellular uptake studies demonstrated that DTX@PLC-SME showed 5.6-fold higher dissolution and 2.3-fold higher DTX uptake in Caco-2 cells than raw material. In addition, an ex vivo gut sac study confirmed that DTX@PLC-SME improved GI permeability of DTX by 2.6-fold compared to raw material. These results suggested that DTX@PLC-SME can significantly overcome the disadvantages of anticancer agents, such as low solubility and permeability.

Investigation of Formulation and Process Parameters of Wet Media Milling to Develop Etodolac Nanosuspensions

PURPOSE

Etodolac (ETD) is one of the non-steroidal anti-inflammatory drugs which has low aqueous solubility issues. The objective of this study was to develop ETD nanosuspensions to improve its poor aqueous solubility properties while investigating formulation and process parameters of wet media milling method via design of experiment (DoE) approach.

METHODS

The critical formulation parameters (CFP) were selected as ETD amount, stabilizer type and ratio as well as critical process parameters (CPP) which were bead size, milling time and milling speed. The two-factorial-2³ and The Box-Benkhen Designs were generated to evaluate CFP and CPP, respectively. Particle size (PS), polydispersity index (PDI) and zeta potential (ZP) were analyzed as dependent variables. Characterization, physical stability and solubility studies were performed.

RESULTS

Optimum nanosuspensions stabilized by PVP K30 and Poloxamer 188 showed 188.5 ± 1.6 and 279.3 ± 6.1 nm of PS, 0.161 ± 0.049 and 0.345 ± 0.007 PDI, 14.8 ± 0.3 and 16.5 ± 0.4 mV of ZP values, respectively. The thermal properties of ETD did not change after milling and lyophilization process regarding to DSC analysis. Also, the crystalline state of ETD was preserved. The morphology of particle was smooth and spherical on SEM. The dry-nanosuspensions stayed physically stable for six months at room temperature. The solubility of nanosuspensions increased up to 13.0-fold in comparison with micronized ETD.

CONCLUSIONS

In conclusion, it is found that the poor solubility issue of ETD can be solved by nanosuspension. DoE approach provided benefits such as reducing number of experiments, saving time and improving final product quality by using wet media milling.

Development and evaluation of TPGS/PVA-based nanosuspension for enhancing dissolution and oral bioavailability of ticagrelor

In this study, we developed ticagrelor-dispersed nanosuspension (TCG-NSP) to enhance the dissolution and oral bioavailability of ticagrelor (TCG) through a statistical design approach. TCG, a reversible P2Y₁₂ receptor antagonist, is classified as a biopharmaceutics classification system (BCS) class IV drug with low solubility and permeability, resulting in low oral bioavailability. Nanosuspension (NSP) is an efficient pharmaceutical technique for overcoming the disadvantages. First, we optimized TCG-NSP consisting of D-α-Tocopherol polyethylene glycol 1000 succinate (TPGS) and polyvinyl alcohol (PVA), which exhibited homogeneously dispersed TCG particle (233 nm) and low precipitation (3%). Characterization studies demonstrated that TCG-NSP provided amorphous TCG particles and supersaturation effect, resulting in higher dissolution than a commercial product. In addition, everted gut sac and pharmacokinetic studies confirmed that TCG-NSP improved the gastrointestinal permeation of TCG by 2.8-fold compared to commercial product, thereby enhancing the oral bioavailability (2.2-fold). These results suggested that TCG-NSP could be successfully used as an efficient pharmaceutical formulation to achieve the enhanced dissolution and oral bioavailability of TCG.

Evaluation of the Solid Dispersion System Engineered from Mesoporous Silica and Polymers for the Poorly Water Soluble Drug Indomethacin: In Vitro and In Vivo

This work explored absorption efficacy via an in vivo imaging system and parallel artificial membrane penetration in indomethacin (IMC) solid dispersion (SD) systems. Two different polymer excipients—hydroxypropyl methylcellulose (HPMC) and Kollicoat IR as precipitation inhibitors (PIs)—combined with mesoporous silica nanoparticles (MSNs) as carriers were investigated. The IMC–SDs were prepared using the solvent evaporation method and characterized by solubility analysis, infrared (IR) spectroscopy, powder X-ray diffraction (PXRD), field emission scanning electron microscopy (FESEM), and differential scanning calorimetry (DSC). It was confirmed that IMC successfully changed into an amorphous state after loading into the designed carriers. The in vitro release and stability experiments were conducted to examine the in vitro dissolution rates of IMC–SDs combined with HPMC and Kollicoat IR as PIs which both improved approximately three-fold to that of the pure drug. Finally, in vivo studies and in vitro parallel artificial membrane penetration (PAMPA) experiments ensured the greater ability of enhancing the dissolution rates of pure IMC in the gastrointestinal tract by oral delivery. In brief, this study highlights the prominent role of HPMC and Kollicoat IR as PIs in MSN SD systems in improving the bioavailability and gastrointestinal oral absorption efficiency of indomethacin.