Febuxostat loaded β-cyclodextrin based nanosponge tablet: an in vitro and in vivo evaluation

Management of hypertension addressing hyperuricaemia: introduction of nano-based approaches

Uric acid (UA) levels in blood serum have been associated with hypertension, indicating a potential causal relationship between high serum UA levels and the progression of hypertension. Therefore, the reduction of serum UA level is considered a potential strategy for lowering and mitigating blood pressure. If an individual is at risk of developing or already manifesting elevated blood pressure, this intervention could be an integral part of a comprehensive treatment plan. By addressing hyperuricaemia, practitioners may subsidize the optimization of blood pressure regulation, which illustrates the importance of addressing UA levels as a valuable strategy within the broader context of hypertension management. In this analysis, we outlined the operational principles of effective xanthine oxidase inhibitors for the treatment of hyperuricaemia and hypertension, along with an exploration of the contribution of nanotechnology to this field.

Febuxostat ternary inclusion complex using SBE7-βCD in presence of a water-soluble polymer: physicochemical characterization, in vitro dissolution, and in vivo evaluation

Febuxostat (FBX), a potent xanthine oxidase inhibitor, is widely used as a blood uric acid-reducing agent and has recently shown a promising repurposing outcome as an anti-cancer. FBX is known for its poor water solubility, which is the main cause of its weak oral bioavailability. In a previous study, we developed a binary system complex between FBX and sulfobutylether-β-cyclodextrin (SBE7-βCD) with improved dissolution behavior. The aim of the current study was to investigate the effect of incorporating a water-soluble polymer with a binary system forming a ternary one, on further enhancement of FBX solubility and dissolution rate. In vivo oral bioavailability was also studied using LC-MS/MS chromatography. The polymer screening study revealed a marked increment in the solubility of FBX with SBE7-βCD in the presence of 5% w/v polyethylene glycol (PEG 6000). In vitro release profile showed a significant increase in the dissolution rate of FBX from FBX ternary complex (FTC). Oral in vivo bioavailability of prepared FTC showed more than threefold enhancement in Cmax value (17.05 ± 2.6 µg/mL) compared to pure FBX Cmax value (5.013 ± 0.417 µg/mL) with 257% rise in bioavailability. In conclusion, the association of water-soluble polymers with FBX and SBE7-βCD system could significantly improve therapeutic applications of the drug.

Novel rivaroxaban-loaded microsphere systems with different surface microstructure for enhanced oral bioavailability

This study compares rivaroxaban-loaded polymeric microsphere systems with three types of surface microstructure. Three types of polymeric microspheres loaded with rivaroxaban were fabricated using a spray-drying technique: solvent-evaporated, surface-attached, and solvent-wet microspheres, depending on whether the drug and additives used are soluble in the solvent. The solvent-evaporated and surface-attached microspheres had a rivaroxaban/polyvinylpyrrolidone/sodium lauryl sulfate (SLS) weight ratio of 1/0.25/2.2, and the solvent-wetted microspheres contained rivaroxaban/polyvinyl alcohol/SLS in equal weight ratio (1/0.25/2). The physicochemical properties of the microspheres were evaluated using scanning electron microscopy, powder X-ray diffraction, differential scanning calorimetry, and particle size distribution analysis. The aqueous solubility and dissolution rate of rivaroxaban in the three types of microspheres were compared to those of the drug powder. The solvent-evaporated, surface-attached, and solvent-wetted microspheres were approximately 208, 140, and 172 times as soluble as the drug powder, and the final dissolution rate (120 min) was approximately 5, 2, and 4 times that of the drug powder, respectively. In addition, the oral bioavailability increased by approximately 2, 1.3, and 1.6 times compared to that of the drug powder (area under drug concentration-time curve: 2101.3 ± 314.8, 1325.2 ± 333.3, and 1664.0 ± 102.6 h·ng/mL, respectively). Finally, the solvent-evaporated microspheres showed the greatest improvement (solvent evaporating microspheres > solvent wetted microspheres > surface-attached microspheres ≥ drug powder). Therefore, the solvent-evaporated microspheres may represent a novel oral dosage form that improves the oral bioavailability of rivaroxaban, a poorly soluble drug.

Febuxostat solubilization and stabilization approach using solid dispersion method: Synergistic effect of dicalcium phosphate dehydrate and chitosan

Drug solubilization studies are continuously being conducted. Febuxostat (FBX) has a low solubility in water. This study aims to develop a stable FBX-solid dispersion (SD) formulation using a solvent evaporation method. The solubilization strategy of FBX is to develope an optimal FBX-SD formulation by selecting a solubilizer and carrier through the screening method. The final selected solubilizer, macrogol 15 hydroxystearate and polyoxyl 15 hydroxystearate (Kolliphor® HS-15), is widely used in the pharmaceutical industry as a nonionic solubilizing and emulsifying agent and has low toxicity. Especially when commonly used in developing lipophilic drug formulations, it dissolves well in water and ethyl alcohol. The optimal composition ratio of the formulation (SD4) was FBX:HS-15®:granular dicalcium phosphate dehydrate (DCP-D): A synthetic magnesium aluminometasilicate (Neusilin®UFL2):chitosan = 1:3:3:1:1 (w/w) and showed 3.0-, 2.3-, and 1.1-fold higher dissolution (%) of FBX compared to that of the Feburic tab® in pH 1.2 media, distilled water (DW), and pH 6.8 buffer, respectively. Also, in vitro release and in vitro permeability in SD4 formulation showed higher than that of Feburic tab®. Based on its stability over 6 months, it was confirmed that chitosan acted as a stabilizer. Moreover, due to weak intermolecular interactions, FBX in the SD4 formulation was considered to exist in a mixed state of amorphous and crystalline FBX. In conclusion, the improved dissolution (%) and stability of FBX in SD4 formulation were secured through the synergistic effect of excipients.

Development and evaluation of febuxostat solid dispersion through screening method

Febuxostat (Febux) is a BCS II drug and has a very low solubility. In order to overcome this shortcoming, the purpose of study is to increase the in vitro dissolution (%) and drug release (%) of Febux by using a screening method. The Febux-SD formulation was prepared by screening solubilizers, pH agents, and carriers using with a solvent evaporation method. The novel Febux SD formulation was successfully developed. The dissolution (%) of Febux of optimal formulation (SD3) was higher than that of Feburic® tab in pH 1.2, distilled water (DW), and pH 6.8 buffer by 6.3-, 2.6-, and 1.1-fold, respectively, at 60 min. The in vitro drug release (%) and permeability (μg/cm2) of SD3 formulation were improved compared to those of Feburic® tab in the pH shifting method and PBS (7.4), respectively. The SD3 formulation was well maintained the stability for 6 months, and that of physicochemical properties were altered. In conclusion, the Febux solubilization study with meglumine was first attempted and successfully performed. Through the improved dissolution (%) of Febux, high bioavailability of SD3 formulation is expected in animal and human studies.

Characterization of Channeling Effects Applied to Extended-Release Matrix Tablets Containing Pirfenidone

Pirfenidone (PRF) is an anti-fibrotic agent that has been approved by the Food and Drug Administration (FDA) for the treatment of mild to moderate idiopathic pulmonary fibrosis. However, the current oral administration dosing regimen of PRF is complex and requires high doses. Patients are instructed to take PRF three times daily, with each dose consisting of up to three capsules or tablets (600 mg/d or 1.8 g/d of PRF) taken with food. To improve the dosing regimen, efforts are being made to develop an extended-release tablet with a zero-order release pattern. In this study, two types of extended-release matrix tablets were compared: non-channeled extended-release matrix tablets (NChMT) and channeled extended-release matrix tablets (ChMT). In vitro release tests, swelling and erosion index, rheology studies, and X-ray microcomputed tomography (XRCT), were conducted. The results indicated that ChMT maintained a zero-order release pattern with a constant release rate, while NChMT exhibited a decreased release rate in the latter half of the dissolution. ChMT exhibited accelerated swelling and erosion compared to other formulations, and this was made possible by the presence of channels within the tablet. These channels allowed for thorough wetting and swelling throughout the entire depth of the tablet. The formation of channels was confirmed through XRCT images. In conclusion, the presence of channels in ChMT tablets increased the rate of swelling and erosion, resulting in a zero-order release pattern. This development offers the potential to improve the dosage of PRF and reduce its associated side effects.

Evaluation of Pharmacokinetic Feasibility of Febuxostat/L-pyroglutamic Acid Cocrystals in Rats and Mice

Febuxostat (FBX), a selective xanthine oxidase inhibitor, belongs to BCS class II, showing low solubility and high permeability with a moderate F value (<49%). Recently, FBX/L-pyroglutamic acid cocrystal (FBX-PG) was developed with an improving 4-fold increase of FBX solubility. Nevertheless, the in vivo pharmacokinetic properties of FBX-PG have not been evaluated yet. Therefore, the pharmacokinetic feasibility of FBX in FBX- and FBX-PG-treated rats and mice was compared in this study. The results showed that the bioavailability (F) values of FBX were 210% and 159% in FBX-PG-treated rats and mice, respectively. The 2.10-fold greater total area under the plasma concentration-time curve from time zero to infinity (AUC0-inf) of FBX was due to the increased absorption [i.e., 2.60-fold higher the first peak plasma concentration (Cmax,1) at 15 min] and entero-hepatic circulation of FBX [i.e., 1.68-fold higher the second peak plasma concentration (Cmax,2) at 600 min] in FBX-PG-treated rats compared to the FBX-treated rats. The 1.59-fold greater AUC0-inf of FBX was due to a 1.65-fold higher Cmax,1 at 5 min, and a 1.15-fold higher Cmax,2 at 720 min of FBX in FBX-PG-treated mice compared to those in FBX-treated mice. FBX was highly distributed in the liver, stomach, small intestine, and lungs in both groups of mice, and the FBX distributions to the liver and lungs were increased in FBX-PG-treated mice compared to FBX-treated mice. The results suggest the FBX-PG has a suitable pharmacokinetic profile of FBX for improving its oral F value.

Electrospun Food Polysaccharides Loaded with Bioactive Compounds: Fabrication, Release, and Applications

Food polysaccharides are well acclaimed in the field of delivery systems due to their natural safety, biocompatibility with the human body, and capability of incorporating/releasing various bioactive compounds. Electrospinning, a straightforward atomization technique that has been attracting researchers worldwide, is also versatile for coupling food polysaccharides and bioactive compounds. In this review, several popular food polysaccharides including starch, cyclodextrin, chitosan, alginate, and hyaluronic acid are selected to discuss their basic characteristics, electrospinning conditions, bioactive compound release characteristics, and more. Data revealed that the selected polysaccharides are capable of releasing bioactive compounds from as rapidly as 5 s to as prolonged as 15 days. In addition, a series of frequently studied physical/chemical/biomedical applications utilizing electrospun food polysaccharides with bioactive compounds are also selected and discussed. These promising applications include but are not limited to active packaging with 4-log reduction against E. coli, L. innocua, and S. aureus; removal of 95% of particulate matter (PM) 2.5 and volatile organic compounds (VOCs); heavy metal ion removal; increasing enzyme heat/pH stability; wound healing acceleration and enhanced blood coagulation, etc. The broad potentials of electrospun food polysaccharides loaded with bioactive compounds are demonstrated in this review.

Solubility and Thermodynamic Properties of Febuxostat in Various (PEG 400 + Water) Mixtures

The solubility of the poorly soluble medicine febuxostat (FXT) (3) in various {polyethylene glycol 400 (PEG 400) (1) + water (H₂O) (2)} mixtures has been examined at 298.2-318.2 K and 101.1 kPa. FXT solubility was measured using an isothermal method and correlated with "van't Hoff, Apelblat, Buchowski-Ksiazczak λh, Yalkowsky-Roseman, Jouyban-Acree, and Jouyban-Acree-van't Hoff models". FXT mole fraction solubility was enhanced via an increase in temperature and PEG 400 mass fraction in {(PEG 400 (1) + H₂O (2)} mixtures. Neat PEG 400 showed the highest mole fraction solubility of FXT (3.11 × 10^-2 at 318.2 K), while neat H₂O had the lowest (1.91 × 10^-7 at 298.2 K). The overall error value was less than 6.0% for each computational model, indicating good correlations. Based on the positive values of apparent standard enthalpies (46.72-70.30 kJ mol^-1) and apparent standard entropies (106.4-118.5 J mol^-1 K^-1), the dissolution of FXT was "endothermic and entropy-driven" in all {PEG 400 (1) + H₂O (2)} mixtures examined. The main mechanism for FXT solvation in {PEG 400 (1) + H₂O (2)} mixtures was discovered to be an enthalpy-driven process. In comparison to FXT-H₂O, FXT-PEG 400 showed the strongest molecular interactions. In conclusion, these results suggested that PEG 400 has considerable potential for solubilizing a poorly soluble FXT in H₂O.

Supersaturation-Based Drug Delivery Systems: Strategy for Bioavailability Enhancement of Poorly Water-Soluble Drugs

At present, the majority of APIs synthesized today remain challenging tasks for formulation development. Many technologies are being utilized or explored for enhancing solubility, such as chemical modification, novel drug delivery systems (microemulsions, nanoparticles, liposomes, etc.), salt formation, and many more. One promising avenue attaining attention presently is supersaturated drug delivery systems. When exposed to gastrointestinal fluids, drug concentration exceeds equilibrium solubility and a supersaturation state is maintained long enough to be absorbed, enhancing bioavailability. In this review, the latest developments in supersaturated drug delivery systems are addressed in depth.

Cyclodextrin-Modified Nanomaterials for Drug Delivery: Classification and Advances in Controlled Release and Bioavailability

In drug delivery, one widely used way of overcoming the biopharmaceutical problems present in several active pharmaceutical ingredients, such as poor aqueous solubility, early instability, and low bioavailability, is the formation of inclusion compounds with cyclodextrins (CD). In recent years, the use of CD derivatives in combination with nanomaterials has shown to be a promising strategy for formulating new, optimized systems. The goals of this review are to give in-depth knowledge and critical appraisal of the main CD-modified or CD-based nanomaterials for drug delivery, such as lipid-based nanocarriers, natural and synthetic polymeric nanocarriers, nanosponges, graphene derivatives, mesoporous silica nanoparticles, plasmonic and magnetic nanoparticles, quantum dots and other miscellaneous systems such as nanovalves, metal-organic frameworks, Janus nanoparticles, and nanofibers. Special attention is given to nanosystems that achieve controlled drug release and increase their bioavailability during in vivo studies.

Fast dissolving nanofiber mat for the local antimicrobial application of roxithromycin in oral cavity

Fast disintegrating and dissolving nanofiber (NF) mat was devised to deliver roxithromycin for the treatment of the respiratory tract infection. NF membrane was made by an electrospinning process with poly(vinyl alcohol) (PVA), hydroxypropyl-β-cyclodextrin (HP-β-CD), and d-α-tocopheryl polyethylene glycol succinate (TPGS) for local application of roxithromycin. Roxithromycin has a poor water solubility thus HP-β-CD is introduced for enhancing drug solubility by forming an inclusion complex in this study. The addition of TPGS provided multiple roles such as accelerating wetting, disintegration, and dissolution speed and overcoming bacterial resistance. Roxithromycin was successfully entrapped in NF structure and drug amorphization occurred during the electrospinning process. PVA/HP-β-CD/TPGS/roxithromycin (PHTR) NF exhibited faster wetting, disintegration, and dissolution speed rather than the other NF mats. PHTR NF displayed higher antibacterial potentials in Gram-negative bacteria (E. coli) and Gram-positive bacteria (S. aureus) compared to other NF mat formulations. The administration of PHTR NF to oral cavity in pneumococcal disease mouse model provided the most efficient therapeutic potentials in lung tissue. Designed multiple phase-based NF mat may be one of powerful local drug delivery systems for the therapy of respiratory tract infection.

Complexation of exenatide and cyclodextrin: An approach for the stabilization and sustained release of exenatide in PLGA microsphere

The purpose of this study was to evaluate the effects of cyclodextrins (CyDs) to stabilize exnatide in the microencapsulation medium and influence on the pharmaceutical properties of exenatide loaded PLGA microsphere. Three CyDs interacted differently with exenatide by investigation using ultraviolet, fluorescence and circular dichroism spectroscopy. The binding affinities of CyDs to the hydrophobic tryptophan residues of exenatide increased in following order: α-CyD < β-CyD < γ-CyD. It was consistent with orders of W/O interface stabilizing and anti-adsorption effects. However, the stabilizing effect of β-CyD on liquid-state and freeze-drying of exenatide was greater than that of γ-CyD. The negative values of ΔH₀, ΔS₀, and ΔG₀ indicated that the exenatide-CyDs complex formation was a favorable exothermic and spontaneous processes that increased the order in the complex with structural rigidity. Furthermore, it was also shown that β-CyD improved encapsulation efficiency, in vitro extended release, and in vivo pharmacokinetic and pharmacodynamic properties of prepared PLGA microspheres.

Preparation of Gastro-retentive Tablets Employing Controlled Superporous Networks for Improved Drug Bioavailability

The development of an oral formulation that ensures increased bioavailability of drugs is a great challenge for pharmaceutical scientists. Among many oral formulation systems, a drug delivery system employing superporous networks was developed to provide a prolonged gastro-retention time as well as improved bioavailability of drugs with a narrow absorption window in the gastrointestinal tract. Superporous networks (SPNs) were prepared from chitosan by crosslinking with glyoxal and poly(vinyl alcohol) (PVA). The SPNs showed less porosity and decreased water uptake with an increase in the crosslinking density and content of PVA. Gastro-retentive tablets (GRTs) were formulated using hydroxypropyl methylcellulose (HPMC, a hydrophilic polymer) and the prepared SPNs. Ascorbic acid (AA), which is mainly absorbed in the proximal part of the small intestine, was selected as a model drug. The formulated GRTs exhibited no floating lag time and stayed afloat until the end of the dissolution test. The in vitro drug release from the GRTs decreased with a decrease in the water uptake of the SPNs. The profile of drug release from the GRTs corresponded to the first-order and Higuchi drug-release models. Overall, floating tablets composed of the SPNs and HPMC have potential as a favorable platform to ensure sustained release and improved bioavailability of drugs that are absorbed in the proximal part of the small intestine.

Design and formulation of polymeric nanosponge tablets with enhanced solubility for combination therapy

Three drugs namely caffeine, paracetamol, and aceclofenac are commonly used for treating various acute and chronic pain related ailments. These 3 drugs have varied solubility profiles, and formulating them into a single tablet did not have the desired dissolution profile for drug absorption. The objective of the present research was to tailor the drug release profile by altering drug solubility. This was achieved by loading the drug into nanosponges. Here, three-dimensional colloidal nanosponges were prepared using β-cyclodextrin with dimethyl carbonate as a cross-linker using the hot-melt compression method. The prepared nanosponges were characterized by FTIR, ¹H NMR spectroscopy, DSC, XRPD studies and SEM. The FTIR and DSC results obtained indicated polymer-drug compatibility. The ¹H NMR spectroscopy results obtained indicated the drug entrapment within nanosponges with the formation of the inclusion complex. XRPD studies showed that the loaded drug had changed crystalline properties altering drug solubility. SEM photographs revealed the porous and spongy texture on the surface of the nanosponge. Box–Behnken experimental design was adopted for the optimization of nanosponge synthesis. Among the synthesized nanosponges containing paracetamol, aceclofenac and caffeine, batch F3–P31, F3–A31 and F3–C31 were considered optimized. Their particle size was 185, 181 and 199 nm with an entrapment efficiency of 81.53, 84.96, and 89.28% respectively. These optimized nanosponges were directly compressed into tablets and were studied for both pre and post-compression properties including in vitro drug release. The prepared tablet showed desired drug dissolution properties compared to the pure drug. The above outcomes indicated the applicability of nanosponges in modulating the drug release with varied solubility for combination therapy.

Polymeric nanosponges as potential carriers for successful combination therapy of poorly soluble drugs (paracetamol, aceclofenac, caffeine).

Current Status of Supersaturable Self-Emulsifying Drug Delivery Systems

Self-emulsifying drug delivery systems (SEDDSs) are a vital strategy to enhance the bioavailability (BA) of formulations of poorly water-soluble compounds. However, these formulations have certain limitations, including in vivo drug precipitation, poor in vitro in vivo correlation due to a lack of predictive in vitro tests, issues in handling of liquid formulation, and physico-chemical instability of drug and/or vehicle components. To overcome these limitations, which restrict the potential usage of such systems, the supersaturable SEDDSs (su-SEDDSs) have gained attention based on the fact that the inclusion of precipitation inhibitors (PIs) within SEDDSs helps maintain drug supersaturation after dispersion and digestion in the gastrointestinal tract. This improves the BA of drugs and reduces the variability of exposure. In addition, the formulation of solid su-SEDDSs has helped to overcome disadvantages of liquid or capsule dosage form. This review article discusses, in detail, the current status of su-SEDDSs that overcome the limitations of conventional SEDDSs. It discusses the definition and range of su-SEDDSs, the principle mechanisms underlying precipitation inhibition and enhanced in vivo absorption, drug application cases, biorelevance in vitro digestion models, and the development of liquid su-SEDDSs to solid dosage forms. This review also describes the effects of various physiological factors and the potential interactions between PIs and lipid, lipase or lipid digested products on the in vivo performance of su-SEDDSs. In particular, several considerations relating to the properties of PIs are discussed from various perspectives.