Fabrication of Ibrutinib Nanosuspension by Quality by Design Approach: Intended for Enhanced Oral Bioavailability and Diminished Fast Fed Variability

Exploration of Abiraterone acetate loaded Nanostructured lipid carriers for bioavailability improvement and circumvention of fast-fed variability

Abiraterone acetate (ABA), a biopharmaceutical class IV drug suffers from solubility and permeability pitfalls resulting in limited oral bioavailability and positive food effect, i.e. multi-fold enhancement in drug absorption in the presence of food. This poses difficulties to physicians towards the estimation of dose and dosage regimen required for efficacious therapy of prostate cancer (PCa). Nanostructured lipid carriers (NLC) have demonstrated tremendous outcomes in enhancing the oral bioavailability of various entities along with food effect attenuation. In this study, Quality by design and multivariate analysis was employed for optimization of ABA loaded NLC (ABA NLC). The optimal size, PDI and zeta potential obtained using QbD were 134.6 nm, 0.163 and -15.7 mV respectively. Ex vivo qualitative and quantitative intestinal permeability studies demonstrated improved traversion of NLC through the intestinal segments. In vitro dissolution profile in biorelevant fast and fed gastric and intestinal media revealed minimal differences for ABA NLC compared to ABA. In vivo pharmacokinetics was performed to decipher the efficacy of ABA NLC in mitigating the food effect of ABA. The studies demonstrated 14.51-fold and 1.94-fold improvement in oral bioavailability during fasted and fed state respectively as compared to free ABA. The absorption mechanism of ABA NLC using chylomicron flow blocking approach conveyed lymphatic uptake as the major mechanism. Cmax fast/fed ratio was 0.9758 whereas, AUC fast/fed ratio was 0.9386, which being nearly equivalent, confirmed the food effect attenuation. Therefore, the results of the study demonstrate optimal pharmacokinetics of ABA NLC and its utility in circumventing the fast fed variability.

Characterization of Amorphous Ibrutinib Thermal Stability

The choice of method for drug amorphization depends on various factors, including the physicochemical properties of the active pharmaceutical ingredients, the desired formulation, and scalability requirements. It is often important to consider a combination of methods or the use of excipients to further enhance the stability and performance of the amorphous drug. This study presents a comparison of techniques including melt quench, hot melt extrusion, solvent evaporation, ball milling, and lyophilization used for the preparation of amorphous ibrutinib. The amorphous material was thoroughly investigated using numerous techniques to examine changes in the physicochemical properties, stability, and degradation pathways of the drug product. During the examination, the temperature was discovered to be a key parameter for controlling the solubility and permeability of ibrutinib, which is influenced by the presence of the degradation product. We found that this degradation product could potentially polymerize and increase the molecular weight. The quantity, polymerization rate, and structure of the impurity can be regulated by the temperature variation during the amorphization processes. Additionally, the molecular weight of the degradation product was determined using Zimm plot analysis, which appeared for the first time in the literature for molecules of this category.

Intensification of quercetin nanobubble formulation and performance by multi-factor optimization and interaction analysis

The natural flavonoid Quercetin (QT) showed a potential for various health benefits, but its pharmaceutical applications are hindered by low solubility, permeability, and limited bioavailability. This research aimed to synthesize, develop and optimize polylactic acid co-glycolic acid (PLGA) nanobubbles using solvent evaporation method as a sustained delivery system for QT, thus improving stability and bioavailability. Through a four-factor, three-level Box Behnken Design, 29 experimental runs were carried out to optimize QT-PLGA nanobubbles. An optimized formulation consisted of 50 mg QT, 250 mg PLGA, and 1.89% w/v PVA. The nanobubbles displayed a particle size of 139.5 ± 6.24 nm, polydispersity index of 0.296 ± 0.19, and zeta potential of -23.0 ± 3.44 mV, with an entrapment efficiency of 59.24 ± 3.08%. Analysis through Fourier transform infrared spectroscopy, differential scanning calorimetry, and X-ray diffraction confirmed no drug-polymer interaction, while scanning electron microscopy revealed a uniform spherical nanoparticle. In vitro studies exhibited an excellent drug release, and stability studies showed no significant changes after one month. In vivo studies in rats demonstrated increased Cmax (3.03) and AUC0-t (5.84), indicating an improved sustained release and absorption. These findings underscored a potential of QT-loaded PLGA nanobubbles to enhance the drug kinetics and bioavailability, offering possibilities for targeted drug delivery and improved therapeutic outcomes.

Formulation and evaluation of ibrutinib-loaded glycyrrhizic acid conjugated ovalbumin nanoparticles and ibrutinib-glycyrrhizic acid complex for improved oral bioavailability

The study aimed at enhancing the oral bioavailability of the BCS class 2 drug Ibrutinib (IBR), which exhibits low solubility (0.002 mg/mL) and high permeability (3.9% oral bioavailability). This was achieved through the formulation and evaluation of Ibrutinib-loaded Glycyrrhizic acid conjugated egg ovalbumin nanoparticles (IBR-GA-EA NPs) and Ibrutinib-Glycyrrhizic acid complex (IBR-GA-COMP). The formulation of Ibrutinib-Glycyrrhizic acid complex aimed to enhance the oral bioavailability of Ibrutinib. Lyophilized Ibrutinib-Glycyrrhizic acid complex was prepared and characterized through various studies including DSC, FTIR, in vitro release, and in vivo pharmacokinetics studies. DSC and FTIR confirmed successful formulation development. The nanoparticles exhibited spherical morphology with favourable characteristics: particle size of 194.10 nm, PDI of 0.22, and zeta potential of -33.96 mV. Encapsulation efficiency was 82.88%. In vitro release study displayed major improvement in drug release pattern compared to the free drug suspension. In vivo pharmacokinetic studies demonstrated 3.21-fold and 3.41-fold increase in the oral bioavailability of IBR-GA-EA NPs and IBR-GA-COMP, respectively, compared to IBR suspension alone. The formulated IBR-GA-EA NPs and IBR-GA-COMP are promising drug delivery methods as they successfully improve the solubility and oral bioavailability of Ibrutinib.

Biopharmaceutical and pharmacokinetic attributes to drive nanoformulations of small molecule tyrosine kinase inhibitors

Buoyed by the discovery of small-molecule tyrosine kinase inhibitors (smTKIs), significant impact has been made in cancer chemotherapeutics. However, some of these agents still encounter off-target toxicities and suboptimal efficacies due to their inferior biopharmaceutical and/or pharmacokinetic properties. Almost all of these molecules exhibit significant inter- and intra-patient variations in plasma concentration-time profiles. Thus, therapeutic drug monitoring, dose adjustments and precision medicine are being contemplated by clinicians. Complex formulations or nanoformulation-based drug delivery systems offer promising approaches to provide drug encapsulation or spatiotemporal control over the release, overcoming the biopharmaceutical and pharmacokinetic limitations and improving the therapeutic outcomes. In this context, the present review comprehensively tabulates and critically analyzes all the relevant properties (T1/2, solubility, pKa, therapeutic index, IC50, metabolism etc.) of the approved smTKIs. A detailed appraisal is conducted on the advancements made in complex formulations of smTKIs, with a focus on strategies to enhance their pharmacokinetic profile, tumor targeting ability, and therapeutic efficacy. Various nanocarrier platforms, have been discussed, highlighting their unique features and potential applications in cancer therapy. Nanoformulations have been shown to improve area under the curve and peak plasma concentration, and reduce dosing frequency for several smTKIs in animal models. It is inferred that extensive efforts will be made in developing complex formulations of smTKIs in near future. There, the review concludes with key recommendations for the developing of smTKIs to facilitate early clinical translation.

In-vivo pharmacokinetic study of ibrutinib-loaded nanostructured lipid carriers in rat plasma by sensitive spectrofluorimetric method using harmonized approach of quality by design and white analytical chemistry

Ibrutinib, an antineoplastic agent tackling chronic lymphocytic leukemia, mantle cell lymphoma, and Waldenstrom's Macroglobulinemia, falls under the category of BCS class II drugs, characterized by a puzzling combination of low solubility and high permeability. Its oral bioavailability remains a perplexing challenge, merely reaching 2.9 % due to formidable first-pass metabolism hurdles. In a bid to surmount this obstacle, researchers embarked on a journey to develop ibrutinib-loaded NLCs (Nanostructured Lipid Carriers) using a methodology steeped in complexity: a Design of Experiments (DoE)-based hot melted ultrasonication approach. Despite a plethora of methods for analyzing ibrutinib in various matrices, the absence of a spectrofluorimetric method for assessing it in rat plasma added to the enigma. Thus emerged a spectrofluorimetric method, embodying principles of white analytical chemistry and analytical quality by design, employing a Placket-Burman design for initial method exploration and a central composite design for subsequent refinement. This method underwent rigorous validation in accordance with ICH guidelines, paving the way for its application in scrutinizing the in-vivo pharmacokinetics of ibrutinib-loaded NLCs, juxtaposed against commercially available formulations. Surprisingly, the optimized NLCs exhibited a striking 1.82-fold boost in oral bioavailability, shedding light on their potential efficacy. The environmental impact of this method was scrutinized using analytical greenness tools, affirming its eco-friendly attributes. In essence, the culmination of these efforts has not only propelled advancements in drug bioavailability but also heralded the dawn of a streamlined and environmentally conscious analytical paradigm.

Quality by design optimization of formulation variables and process parameters for enhanced transdermal delivery of nanosuspension

This investigation aims to fabricate, characterize, and optimize organogel containing andrographolide nanosuspension to enhance transdermal drug delivery into and across the skin in vitro. We identified the critical material attributes (CMAs) and critical process parameters (CPPs) that impact key characteristics of andrographolide nanosuspension using a systematic quality-by-design approach. We prepared andrographolide nanosuspension using the wet milling technique and evaluated various properties of the formulations. The CMAs were types and concentrations of polymers, types and concentrations of surfactants, drug concentration, and lipid concentration. The CPPs were volume of milling media and milling duration. Mean particle size, polydispersity index, encapsulation efficiency, and drug loading capacity as critical quality attributes were selected in the design for the evaluation and optimization of the formulations. Furthermore, we developed and evaluated organogel formulation to carry andrographolide nanosuspension 0.05% w/w. Drug release and permeation studies were conducted to assess the drug release kinetics and transdermal delivery of andrographolide. We presented the alteration in the average particle size, polydispersity index, encapsulation efficiency, drug-loading capacity, and drug release among various formulations to select the optimal parameters. The permeation study indicated that organogel delivered markedly more drug into the receptor fluid and skin tissue than DMSO gel (n = 3, p < 0.05). This enhancement in transdermal drug delivery was demonstrated by cumulative drug permeation after 24 h, steady-state flux, permeability coefficient, and predicted steady-state plasma concentration. Drug quantity in skin layers, total delivery, delivery efficiency, and topical selectivity were also reported. Conclusively, andrographolide nanosuspension-loaded organogel significantly increased transdermal drug delivery in vitro.

Precious Cargo: The Role of Polymeric Nanoparticles in the Delivery of Covalent Drugs

Covalent drugs can offer significant advantages over non-covalent drugs in terms of pharmacodynamics (i.e., target-binding properties). However, the development of covalent drugs is sometimes hampered by pharmacokinetic limitations (e.g., low bioavailability, rapid metabolism and toxicity due to off-target binding). Polymeric nanoparticles offer a potential solution to these limitations. Delivering covalent drugs via polymeric nanoparticles provides myriad benefits in terms of drug solubility, permeability, lifetime, selectivity, controlled release and the opportunity for synergistic administration alongside other drugs. In this short review, we examine each of these benefits in turn, illustrated through multiple case studies.

Drug Nanocrystals in Oral Absorption: Factors That Influence Pharmacokinetics

Despite the safety and convenience of oral administration, poorly water-soluble drugs compromise absorption and bioavailability. These drugs can exhibit low dissolution rates, variability between fed and fasted states, difficulty permeating the mucus layer, and P-glycoprotein efflux. Drug nanocrystals offer a promising strategy to address these challenges. This review focuses on the opportunities to develop orally administered nanocrystals based on pharmacokinetic outcomes. The impacts of the drug particle size, morphology, dissolution rate, crystalline state on oral bioavailability are discussed. The potential of the improved dissolution rate to eliminate food effects during absorption is also addressed. This review also explores whether permeation or dissolution drives nanocrystal absorption. Additionally, it addresses the functional roles of stabilizers. Drug nanocrystals may result in prolonged concentrations in the bloodstream in some cases. Therefore, nanocrystals represent a promising strategy to overcome the challenges of poorly water-soluble drugs, thus encouraging further investigation into unclear mechanisms during oral administration.

Quality-by-design driven approach in the formulation of an anti-ulcer and gastro-protective oral suspension

OBJECTIVE

This work aims to present a Quality-by-Design (QbD) step-by-step methodology to formulate anti-ulcer and gastro-protective oral suspensions.

METHODS

Sucralfate was used as a drug model. The Quality Target Product Profile was established early during preformulation. Viscosity, resuspendability, pH, and density were assessed through the screening of several suspension platforms based on different prototype compositions. A compatibility study between the active pharmaceutical ingredient and the excipients was performed by thermal analysis and infrared spectroscopy. An Ishikawa fishbone diagram and Failure Mode and Effect Analysis were employed to identify the Critical Material Attributes (CMAs), Critical Process Parameters (CPPs), and Critical Quality Attributes (CQAs). CMAs' and CPPs' impact on identified CQAs was further assessed through a 22 full factorial experimental design at normal conditions after manufacture and one month at super-accelerated stress conditions. Results: The lead prototype exhibited no physicochemical incompatibilities. The risk assessment tools revealed that the concentration of the wetting agent and the total concentration of thickening agents represented critical factors for the quality profile of the preparation in terms of viscosity. The optimized formulation comprising 1.125 w/v% total concentration of Natrosol 250 HX and Avicel RC 591 exhibited an enhanced performance according to the established profile.

CONCLUSIONS

The analytical and physicochemical tests showed the robustness and compliance of the final preparation with the quality profile. The proposed step-by-step methodology based on QbD, Design of Experiments, and Quality Risk Management presented in our research holds practical implications for local industries and formulation scientists involved in the development of oral suspensions.

Ibrutinib topical delivery for melanoma treatment: The effect of nanostructured lipid carriers' composition on the controlled drug skin deposition

Melanoma is responsible for more than 80% of deaths related to skin diseases. Ibrutinib (IBR), a Bruton's tyrosine kinase inhibitor, has been proposed to treat this type of tumor. However, its low solubility, extensive first-pass effect, and severe adverse reactions with systemic administration affect therapeutic success. This study proposes developing and comparing the performance of two compositions of nanostructured lipid carriers (NLCs) to load IBR for the topical management of melanomas in their early stages. Initially, the effectiveness of IBR on melanoma proliferation was evaluated in vitro, and the results confirmed that the drug reduces the viability of human melanoma cells by inducing apoptosis at a dose that does not compromise dermal cells. Preformulation tests were then conducted to characterize the physical compatibility between the drug and the selected components used in NLCs preparation. Sequentially, two lipid compositions were used to develop the NLCs. Formulations were then characterized and subjected to in vitro release and permeation tests on porcine skin. The NLCs containing oleic acid effectively controlled IBR release over 24 h compared to the NLCs composed of pomegranate seed oil. Furthermore, the nanoparticles acted as permeation enhancers, increasing the fluidity of the lipids in the stratum corneum, as determined by EPR spectroscopy, which stimulated the IBR penetration more profoundly into the skin. However, the NLCs composition also influenced the permeation promotion factor. Thus, these findings emphasize the importance of the composition of NLCs in controlling and increasing the skin penetration of IBR and pave the way for future advances in melanoma therapy.

Oral delivery of posaconazole-loaded phospholipid-based nanoformulation: Preparation and optimization using design of experiments, machine learning, and TOPSIS

Phospholipid-based nanosystems show promising potentials for oral administration of hydrophobic drugs. The study introduced a novel approach to optimize posaconazole-loaded phospholipid-based nanoformulation using the design of experiments, machine learning, and Technique for Order of Preference by Similarity to the Ideal Solution. These approaches were used to investigate the impact of various variables on the encapsulation efficiency (EE), particle size, and polydispersity index (PDI). The optimized formulation, with %EE of ∼ 74 %, demonstrated a particle size and PDI of 107.7 nm and 0.174, respectively. The oral pharmacokinetic profiles of the posaconazole suspension, empty nanoformulation + drug suspension, and drug-loaded nanoformulation were evaluated. The nanoformulation significantly increased maximum plasma concentration and the area under the drug plasma concentration-time curve (∼3.9- and 6.2-fold, respectively) and could be administered without regard to meals. MTT and histopathological examinations were carried out to evaluate the safety of the nanoformulation and results exhibited no significant toxicity. Lymphatic transport was found to be the main mechanism of oral delivery. Caco-2 cell studies demonstrated that the mechanism of delivery was not based on an increase in cellular uptake. Our study represents a promising strategy for the development of phospholipid-based nanoformulations as efficient and safe oral delivery systems.

Nanosuspension encapsulated chitosan-pectin microbeads as a novel delivery platform for enhancing oral bioavailability

The current study aimed to overcome the poor solubility and colon-specific delivery of curcumin (CUR) by formulating a curcumin nanosuspension (CUR-NS) using the antisolvent precipitation method. Freeze-dried CUR-NS was encapsulated into microbeads (CUR-NS-MB) by the ionotropic gelation method using zinc chloride (as a cross-linking agent) with the help of rate-controlling polymers, pectin, and chitosan. Furthermore, cellulose acetate phthalate (CAP) is incorporated as an enteric polymer to protect against acidic medium degradation. Particle size, surface morphology, interaction studies, and entrapment studies were performed to optimize CUR-NSs. Nanosuspensions stabilized with hydroxypropyl methylcellulose (HPMC E-15; 1 % w/v) showed an average particle size of 193.5 ± 4.31 nm and a polydispersity index (PDI) of 0.261 ± 0.020. The optimized microbeads (CUR-NS-MB) showed 89.45 ± 3.11 % entrapment efficiency with a drug loading of 14.54 ± 1.02 %. The optimized formulation (CUR-NS-MB) showed colon-specific in vitro drug release bypassing acid pH degradation. In animal studies, a 2.5-fold increase in Cmax and a 4.4-fold increase in AUC048h were observed with CUR-NS-MB, which was more significant than that of plain CUR. Therefore, the developed CUR-NS-MB has the potential to be used as a colon-specific delivery system.

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.

Core Shell Lipid-Polymer Hybrid Nanoparticles for Oral Bioavailability Enhancement of Ibrutinib via Lymphatic Uptake

The purpose of this research was to develop ibrutinib (IBR)-loaded lipid-polymer hybrid nanoparticles (IBR-LPHNPs) to improve oral absorption by intestinal lymphatic uptake. IBR-LPHNPs were fabricated by nanoprecipitation method using poly(lactic-co-glycolic acid), lipoid S 100, and DSPE-MPEG 2000. The IBR-LPHNPs showed particle size of 85.27±3.82 nm, entrapment efficiency of 97.70±3.85%, and zeta potential of -24.9±3.08 mV respectively. Fourier transform infrared spectroscopy and differential scanning calorimetry study revealed compatibility between IBR and excipients. X-ray diffraction study showed the conversion of IBR into amorphous form. High-resolution transmission electron microscopic image displayed spherical-shaped, discrete layered polymeric core and lipid shell structure. The drug release from IBR-LPHNPs exhibited prolong release profile up to 48 h and was best fitted to Korsmeyer-Peppas model. Higher fluorescence intensity at the end of 2 h in the intestinal tissue confirmed the uptake of LPHNPs by Peyer's patches. The oral bioavailability of IBR was improved 22.52-fold with LPHNPs as compared to free IBR. The intestinal lymphatic uptake study in rats pretreated with cycloheximide confirmed the intestinal lymphatic uptake of IBR-LPHNPs. All the results conclusively showed that LPHNPs could be a promising approach to improve oral bioavailability of IBR.

Ibrutinib amorphous solid dispersions with enhanced dissolution at colonic pH for the localized treatment of colorectal cancer

Colorectal cancer (CRC) is the second most leading cause of cancer-related deaths worldwide. Ibrutinib (IBR), the first in class bruton tyrosine kinase (BTK) inhibitor has promising anticancer activity. In this study, we aimed to develop a hot melt extrusion based amorphous solid dispersions (ASD) of IBR with enhanced dissolution at colonic pH and assess the anticancer activity against colon cancer cell lines. Since colonic pH is higher in CRC patients compared to healthy individuals, Eudragit® FS100 was used as pH dependent polymeric matrix for colon enabled release of IBR. Poloxamer 407, TPGS and poly(2-ethyl-2-oxazoline) were screened as plasticizer and solubilizer to improve the processability and solubility. Solid state characterization and filament appearance confirmed that IBR was molecularly dispersed within FS100+TPGS matrix. In-vitro drug release of ASD showed >96% drug release within 6 h at colonic pH with no precipitation for 12 h. Contrary, crystalline IBR showed negligible release. ASD with TPGS showed significantly higher anticancer activity in 2D and multicellular 3D spheroids of colon carcinoma cell lines (HT-29 and HT-116). The outcomes of this research suggested that ASD with a pH dependent polymer is a promising strategy to improve solubility and an effective approach in colorectal cancer targeting.

Pharmacokinetics and Anti-Diabetic Studies of Gliclazide Nanosuspension

Gliclazide (GCZ), an antidiabetic medication, has poor solubility and limited oral bioavailability due to substantial first-pass metabolism. Thus, the purpose of the current study was to optimize and formulate a GCZ nanosuspension (NS) employing the antisolvent precipitation technique. A three-factor, three-level Box–Behnken design (BBD) was used to examine the impact of the primary formulation factors (drug concentration, stabilizer, and surfactant %) on particle size. The optimized NS contains 29.6 mg/mL drug, 0.739% lecithin, and 0.216% sodium dodecyl sulfate (SDS). Under scanning microscopy, the topography of NS revealed spherical particles. Furthermore, NS had a much better saturation solubility than the pure material, which resulted in a rapid dissolving rate, which was attributed to the amorphous structure and smaller particle size of the NS particles. Studies on intestinal permeability using the in vitro noneverted intestinal sac gut method (duodenum, jejunum, and ileum) and single-pass intestinal permeability (SPIP) techniques showed that the effective permeability was also increased by more than 3 fold. In the pharmacokinetic study, the C_max and AUC_0–t values of NS were approximately 3.35- and 1.9-fold higher than those of the raw medication and marketed formulation (MF). When compared to plain drug and commercial formulations, the antidiabetic efficacy of NS demonstrated that it had a significant impact on lowering glucose levels.

Fast-Fed Variability: Insights into Drug Delivery, Molecular Manifestations, and Regulatory Aspects

Among various drug administration routes, oral drug delivery is preferred and is considered patient-friendly; hence, most of the marketed drugs are available as conventional tablets or capsules. In such cases, the administration of drugs with or without food has tremendous importance on the bioavailability of the drugs. The presence of food may increase (positive effect) or decrease (negative effect) the bioavailability of the drug. Such a positive or negative effect is undesirable since it makes dosage estimation difficult in several diseases. This may lead to an increased propensity for adverse effects of drugs when a positive food effect is perceived. However, a negative food effect may lead to therapeutic insufficiency for patients suffering from life-threatening disorders. This review emphasizes the causes of food effects, formulation strategies to overcome the fast-fed variability, and the regulatory aspects of drugs with food effects, which may open new avenues for researchers to design products that may help to eliminate fast-fed variability.

Effects of Polymers on the Drug Solubility and Dissolution Enhancement of Poorly Water-Soluble Rivaroxaban

The purpose of this study was to investigate the efficacy of hydrophilic polymers in a solid dispersion formulation in improving the solubility and dissolution rate of rivaroxaban (RXB), a poorly soluble drug. The developed solid dispersion consisted of two components, a drug and a polymer, and the drug was dispersed as amorphous particles in a polymer matrix using the spray drying method. Polymeric solid dispersions were evaluated using solubility tests, in vitro dissolution tests, powder X-ray diffraction, differential scanning calorimetry, scanning electron microscopy, and particle size distribution analysis. To maximize physical stability against crystallization and improve the solubility and dissolution of RXB, it is important to select the appropriate polymer type and the optimal ratio of the polymer to the drug. The optimized polyvinyl alcohol (PVA)-based (1/0.5, w/w) and gelatin-based (1/5, w/w) solid dispersion formulations showed 6.3 and 3.6 times higher drug solubilities than pure RXB powder, respectively, and the final dissolution rate was improved by approximately 1.5 times. Scanning electron microscopy and particle size distribution analyses confirmed that the gelatin-based solid dispersion was smaller and more spherical than the PVA-based solid dispersion, suggesting that the gelatin-based solid dispersion had a faster initial dissolution rate. Differential scanning calorimetry and powder X-ray diffraction analyses confirmed that RXB had successfully changed from a crystalline form to an amorphous form, contributing to the improvement in its solubility and dissolution rate. This study provides a strategy for selecting suitable polymers for the development of amorphous polymer solid dispersions that can overcome precipitation during dissolution and stabilization of the amorphous state. In addition, the selected polymer solid dispersion improved the drug solubility and dissolution rate of RXB, a poorly soluble drug, and may be used as a promising drug delivery system.

Brain-Targeted Intranasal Delivery of Zotepine Microemulsion: Pharmacokinetics and Pharmacodynamics

The purpose of our study was to improve the solubility, bioavailability, and efficacy of zotepine (ZTP) by brain-targeted intranasal delivery of microemulsion (ME) and its physicochemical properties, the pharmacokinetic and pharmacodynamic parameters were evaluated. The optimized ME formulations contain 10% w/w of oil (Capmul MCM C8, monoglycerides, and diglycerides of caprylic acid), 50% w/w of Smix (Labrasol and Transcutol HP, and 40% w/w of water resulting in a globule size of 124.6 ±3.52 nm with low polydispersity index (PDI) (0.212 ± 0.013) and 2.8-fold higher permeation coefficient through porcine nasal mucosa compared to pure drug. In vitro cell line studies on RPMI 2650, Beas-2B, and Neuro-2A revealed ZTP-ME as safe. ZTP-ME administered intranasally showed higher AUC0-t24 (18.63 ± 1.33 h x µg/g) in the brain by approximately 4.3-fold than oral ME (4.30 ± 0.92 h × µg/g) and 7.7-fold than intravenous drug solutions (2.40 ± 0.36 h × µg/g). In vivo anti-schizophrenic activity was conducted using catalepsy test scores, the formulation showed better efficacy via the intranasal route; furthermore, there was no inflammation or hemorrhage in the nasal cavity. The results concluded that the ZTP microemulsion as a safe and effective strategy could greatly enhance brain distribution by intranasal administration.

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.

A Systematic Approach to the Development of Cilostazol Nanosuspension by Liquid Antisolvent Precipitation (LASP) and Its Combination with Ultrasound

Nanosizing is an approach to improve the dissolution rate of poorly soluble drugs. The first aim of this work was to develop nanosuspension of cilostazol with liquid antisolvent precipitation (LASP) and its combination with ultrasound. Second, to systematically study the effect of bottom-up processing factors on precipitated particles’ size and identify the optimal settings for the best reduction. After solvent and stabilizer screening, in-depth process characterization and optimization was performed using Design of Experiments. The work discusses the influence of critical factors found with statistical analysis: feed concentration, stabilizer amount, stirring speed and ultrasound energy governed by time and amplitude. LASP alone only generated particle size of a few microns, but combination with ultrasound was successful in nanosizing (d10 = 0.06, d50 = 0.33, d90 = 1.45 µm). Micro- and nanosuspension’s stability, particle morphology and solid state were studied. Nanosuspension displayed higher apparent solubility than equilibrium and superior dissolution rate over coarse cilostazol and microsuspension. A bottom-up method of precipitation-sonication was demonstrated to be a successful approach to improve the dissolution characteristics of poorly soluble, BCS class II drug cilostazol by reducing its particle size below micron scale, while retaining nanosuspension stability and unchanged crystalline form.

Btk Inhibitors: A Medicinal Chemistry and Drug Delivery Perspective

In the past few years, Bruton’s tyrosine Kinase (Btk) has emerged as new target in medicinal chemistry. Since approval of ibrutinib in 2013 for treatment of different hematological cancers (as leukemias and lymphomas), two other irreversible Btk inhibitors have been launched on the market. In the attempt to overcome irreversible Btk inhibitor limitations, reversible compounds have been developed and are currently under evaluation. In recent years, many Btk inhibitors have been patented and reported in the literature. In this review, we summarized the (ir)reversible Btk inhibitors recently developed and studied clinical trials and preclinical investigations for malignancies, chronic inflammation conditions and SARS-CoV-2 infection, covering advances in the field of medicinal chemistry. Furthermore, the nanoformulations studied to increase ibrutinib bioavailability are reported.

Lentinan as a natural stabilizer with bioactivities for preparation of drug-drug nanosuspensions

Lentinan is a natural β-glucan with various bioactivities and is combined with chemotherapy drugs for cancer treatment. Regorafenib is an oral multi-kinase inhibitor approved by FDA for treatment of metastatic colorectal cancer, advanced hepatocellular carcinoma, and metastatic gastrointestinal stromal tumors. Regorafenib has poor water solubility and multiple toxicities. We report drug-drug nanosuspensions of regorafenib and lentinan. Results of dynamic light scattering and scanning electron microscopy showed that the mean particle size of the regorafenib-lentinan nanosuspensions was approximately 200 nm and was uniformly distributed. Transmission electron microscopy findings indicated that lentinan stabilized the nanosuspensions by steric manner. Hydrogen bonds and hydrophobic interactions were found between regorafenib and lentinan by molecular dynamics simulation. The results of cytotoxicity assay and pharmacokinetics study in rats showed that the regorafenib-lentinan nanosuspensions reduced the toxicity and enhanced the in vitro anticancer activity and oral bioavailability of regorafenib. Lentinan as a natural stabilizer has the potential using for drug nanosuspensions. Drug-drug nanosuspensions are a new form of combination therapies that can reduce the number of drugs taken by patients and improve their compliance.

QbD aided development of ibrutinib-loaded nanostructured lipid carriers aimed for lymphatic targeting: evaluation using chylomicron flow blocking approach

Ibrutinib (IBR) is the choice of drug for the treatment of chronic lymphocytic leukaemia (CLL) and mantle cell lymphoma (MCL). IBR has low oral bioavailability of 2.9% owing to its high first pass metabolism. Present study was aimed to develop the nanostructured lipid carriers (NLC) using glyceryl monostearate (GMS) as solid lipid and Capryol™ PGMC as liquid lipid. Plackett-Burman design (PBD) was applied to screen the significant factors; furthermore, these significant factors were subjected to optimisation using Central Composite design (CCD). The size, poly dispersity index (PDI) and entrapment efficiency (E.E.) of the developed NLC were 106.4 ± 8.66 nm, 0.272 ± 0.005 and 70.54 ± 5.52% respectively. Morphological evaluation using transmission electron microscope (TEM) and field emission scanning electron microscope (FESEM) revealed spherical particles. Furthermore, differential scanning calorimetry (DSC) indicates the formation of molecular dispersion of drug in the melted lipid matrix while Powder X-Ray Diffraction (PXRD) studies reveal the absence of crystalline drug peaks in the formulation diffractogram. In-vivo pharmacokinetics of NLC displayed an increase in C_max (2.89-fold), AUC_0-t (5.32-fold) and mean residence time (MRT) (1.82-fold) compared with free drug. Furthermore, lymphatic uptake was evaluated by chylomicron flow blocking approach using cycloheximide (CXI). The pharmacokinetic parameters C_max, AUC_0-t and MRT of NLC without CXI were 2.75, 3.57 and 1.30 folds higher compared with NLC with CXI. The difference in PK parameters without CXI indicates significant lymphatic uptake of the formulation. Hence, NLC can be a promising approach to enhance the oral bioavailability of drugs with high first-pass metabolism. Graphical abstract.

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.