Anti-inflammatory drug nanocrystals: state of art and regulatory perspective

Biomimetic nanoplatform treats myocardial ischemia/reperfusion injury by synergistically promoting angiogenesis and inhibiting inflammation

After myocardial ischemia/reperfusion injury (MI/RI), endothelial cell injury causes impaired angiogenesis and obstruction of microcirculation, resulting in an inflammatory outburst that exacerbates the damage. Therefore, synergistic blood vessel repair and inflammation inhibition are effective therapeutic strategies. In this study, we developed a platelet membrane (PM)-encapsulated baicalin nanocrystalline (BA NC) nanoplatform with a high drug load, BA NC@PM, which co-target to endothelial cells and macrophages through the transmembrane proteins of the PM to promote angiogenesis and achieve anti-inflammatory effects. In vitro cell scratch assays and transwell assay manifested that BA NC@PM could promote endothelial cell migration, as well as increase mRNA expression of CD31 and VEGF in the heart after treatment of MI/RI mice, suggesting its favorable vascular repair function. In addition, the preparation significantly reduced the expression of pro-inflammatory factors and increased the expression of anti-inflammatory factors in plasma, promoting the polarization of macrophages. Our study highlights a strategy for enhancing the treatment of MI/RI by promoting angiogenesis and regulating macrophage polarization via the biomimetic BA NC@PM nanoplatform.

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.

Nanosuspensions in ophthalmology: Overcoming challenges and enhancing drug delivery for eye diseases

This review article provides a comprehensive overview of the advancements in using nanosuspensions for controlled drug delivery in ophthalmology. It highlights the significance of ophthalmic drug delivery due to the prevalence of eye diseases and delves into various aspects of this field. The article explores molecular mechanisms, drugs used, and physiological factors affecting drug absorption. It also addresses challenges in treating both anterior and posterior eye segments and investigates the role of mucus in obstructing micro- and nanosuspensions. Nanosuspensions are presented as a promising approach to enhance drug solubility and absorption, covering formulation, stability, properties, and functionalization. The review discusses the pros and cons of using nanosuspensions for ocular drug delivery and covers their structure, preparation, characterization, and applications. Several graphical representations illustrate their role in treating various eye conditions. Specific drug categories like anti-inflammatory drugs, antihistamines, glucocorticoids, and more are discussed in detail, with relevant studies. The article also addresses current challenges and future directions, emphasizing the need for improved nanosuspension stability and exploring potential technologies. Nanosuspensions have shown substantial potential in advancing ophthalmic drug delivery by enhancing solubility and absorption. This article is a valuable resource for researchers, clinicians, and pharmaceutical professionals in this field, offering insights into recent developments, challenges, and future prospects in nanosuspension use for ocular drug delivery.

Characterization of chitosan- and β-cyclodextrin-modified forms of magnesium-doped hydroxyapatites as enhanced carriers for levofloxacin: loading, release, and anti-inflammatory properties

An advanced form of magnesium-rich hydroxyapatite (Mg·HAP) was modified with two types of biopolymers, namely chitosan (CH/Mg·HAP) and β-cyclodextrin (CD/Mg·HAP), producing two types of bio-composites. The synthesized materials were developed as enhanced carriers for levofloxacin to control its loading, release, and anti-inflammatory properties. The polymeric modification significantly improved the loading efficiency to 281.4 mg g-1 for CH/Mg·HAP and 332.4 mg g-1 for CD/Mg·HAP compared with 218.3 mg g-1 for Mg·HAP. The loading behaviors were determined using conventional kinetic and isotherm models and mathematical parameters of new equilibrium models (the monolayer model of one energy). The estimated density of effective loading sites (Nm (LVX) = 88.03 mg g-1 (Mg·HAP), 115.8 mg g-1 (CH/Mg·HAP), and 138.5 mg g-1 (CD/Mg·HAP)) illustrates the markedly higher loading performance of the modified forms of Mg·HAP. Moreover, the loading energies (<40 kJ mol-1) in conjunction with the capacity of each loading site (n > 1) and Gaussian energies (<8 kJ mol-1) signify the physical trapping of LVX molecules in vertical orientation. The addressed materials validate prolonged and continuous release behaviors. These behaviors accelerated after the modification procedures, as the complete release was identified after 160 h (CH/Mg·HAP) and 200 h (CD/Mg·HAP). The releasing behaviors are regulated by both diffusion and erosion mechanisms, according to the kinetic investigations and diffusion exponent analysis (>0.45). The entrapping of LVX into Mg·HAP induces its anti-inflammatory properties against the generation of cytokines (IL-6 and IL-8) in human bronchial epithelia cells (NL20), and this effect displays further enhancement after the integration of chitosan and β-cyclodextrin.

Formulation and optimization of pH-sensitive nanocrystals for improved oral delivery

The challenge of low water solubility in pharmaceutical science profoundly impacts drug absorption and therapeutic effectiveness. Nanocrystals (NC), consisting of drug molecules and stabilizing agents, offer a promising solution to enhance solubility and control release rates. In the pharmaceutical industry, top-down techniques are favored for their flexibility and cost-effectiveness. However, increased solubility can lead to premature drug dissolution in the stomach, which is problematic due to the acidic pH or enzymes. Researchers are exploring encapsulating agents that facilitate drug release at customized pH levels as a valuable strategy to address this. This study employed wet milling and spray drying techniques to create encapsulated NC for delivering the drug to the intestinal tract using the model drug ivermectin (IVM). Nanosuspensions (NS) were efficiently produced within 2 h using NanoDisp®, with a particle size of 198.4 ± 0.6 nm and a low polydispersity index (PDI) of 0.184, ensuring uniformity. Stability tests over 100 days at 4 °C and 25 °C demonstrated practical viability, with no precipitation or significant changes observed. Cytotoxicity evaluations indicated less harm to Caco-2 cells compared to the pure drug. Furthermore, the solubility of the NC increased by 47-fold in water and 4.8-fold in simulated intestinal fluid compared to the pure active compound. Finally, dissolution tests showed less than 10% release in acidic conditions and significant improvement in simulated intestinal conditions, promising enhanced drug solubility and bioavailability. This addresses a long-standing pharmaceutical challenge in a cost-effective and scalable manner.

Nanosuspensions technology as a master key for nature products drug delivery and In vivo fate

The drug nanosuspensions is a universal formulation approach for improved drug delivery of hydrophobic drugs and one the most promising approaches for increasing the biopharmaceutical performance of poorly water-soluble drug substances, especially for nature products. This review aimed to summarize the nanosuspensions preparation approaches and the main technological difficulties encountered in nanosuspensions development, such as guidelines for stabilizers screening, in vivo fate of the intravenously administrated nanosuspensions, and how to realize the intravenously target delivery was reviewed. Furthermore, challenges of nanosuspensions for the nature products delivery also was discussed and commented. Therefore, it hoped to provide reference and assistance for the nanosuspensions production, stabilizers usage, and predictability of in vivo fate and controllability of targeting delivery of the nature products nanosuspensions.

Rutin Nanocrystals with Enhanced Anti-Inflammatory Activity: Preparation and Ex Vivo/In Vivo Evaluation in an Inflammatory Rat Model

Rutin is a polyphenolic flavonoid with an interestingly wide therapeutic spectrum. However, its clinical benefits are limited by its poor aqueous solubility and low bioavailability. In an attempt to overcome these limitations, rutin nanocrystals were prepared using various stabilizers including nonionic surfactants and nonionic polymers. The nanocrystals were evaluated for particle size, zeta potential, drug entrapment efficiency, morphology, colloidal stability, rutin photostability, dissolution rate, and saturation solubility. The selected nanocrystal formulation was dispersed in a hydrogel base and the drug release kinetics and permeability through mouse skin were characterized. Rutin's anti-inflammatory efficacy was studied in a carrageenan-induced rat paw edema model. The nanocrystals had a size in the range of around 270-500 nm and a polydispersity index of around 0.3-0.5. Nanocrystals stabilized by hydroxypropyl beta-cyclodextrin (HP-β-CD) had the smallest particle size, highest drug entrapment efficiency, best colloidal stability, and highest drug photostability. Nanocrystals had around a 102- to 202-fold and 2.3- to 6.7-fold increase in the drug aqueous solubility and dissolution rate, respectively, depending on the type of stabilizer. HP-β-CD nanocrystals hydrogel had a significantly higher percent of drug released and permeated through the mouse skin compared with the free drug hydrogel. The cumulative drug amount permeated through the skin was 2.5-fold higher than that of the free drug hydrogel. In vivo studies showed that HP-β-CD-stabilized rutin nanocrystals hydrogel had significantly higher edema inhibition compared with the free drug hydrogel and commercial diclofenac sodium gel. These results highlight the potential of HP-β-CD-stabilized nanocrystals as a promising approach to enhance drug solubility, dissolution rate, and anti-inflammatory properties.

Silymarin nanocrystals-laden chondroitin sulphate-based thermoreversible hydrogels; A promising approach for bioavailability enhancement

Hydrogels has gained tremendous interest as a controlled release drug delivery. However, currently it is a big challenge to attain high drug-loading as well as stable and sustained release of hydrophobic drugs. The poor aqueous solubility and low bioavailability of many drugs have driven the need for research in new formulations. This manuscript hypothesized that incorporation of nanocrystals of hydrophobic drug, such as silymarin into thermoreversible hydrogel could be a solution to these problems. Herein, we prepared nanocrystals of silymarin by antisolvent precipitation technique and characterized for morphology, particle size, polydispersity index (PDI) and zeta potential. Moreover, physical cross-linking of hydrogel formulations based on chondroitin sulphate (CS), kappa-Carrageenan (κ-Cr) and Pluronic® F127 was confirmed by Fourier transformed infrared spectroscopy (FT-IR). The hydrogel gelation time and temperature of optimized hydrogel was 14 ± 3.2 s and 34 ± 0.6 °C, respectively. The release data revealed controlled release of silymarin up to 48 h and in-vivo pharmacokinetic profiling was done in rabbits and further analyzed by high-performance liquid chromatography (HPLC). It is believed that the nanocrystals loaded thermoreversible injectable hydrogel system fabricated in this study provides high drug loading as well as controlled and stable release of hydrophobic drug for extended period.

Drug Nanocrystals: Focus on Brain Delivery from Therapeutic to Diagnostic Applications

The development of new drugs is often hindered by low solubility in water, a problem common to nearly 90% of natural and/or synthetic molecules in the discovery pipeline. Nanocrystalline drug technology involves the reduction in the bulk particle size down to the nanosize range, thus modifying its physico-chemical properties with beneficial effects on drug bioavailability. Nanocrystals (NCs) are carrier-free drug particles surrounded by a stabilizer and suspended in an aqueous medium. Due to high drug loading, NCs maintain a potent therapeutic concentration to produce desirable pharmacological action, particularly useful in the treatment of central nervous system (CNS) diseases. In addition to the therapeutic purpose, NC technology can be applied for diagnostic scope. This review aims to provide an overview of NC application by different administration routes, especially focusing on brain targeting, and with a particular attention to therapeutic and diagnostic fields. NC therapeutic applications are analyzed for the most common CNS pathologies (i.e., Parkinson's disease, psychosis, Alzheimer's disease, etc.). Recently, a growing interest has emerged from the use of colloidal fluorescent NCs for brain diagnostics. Therefore, the use of NCs in the imaging of brain vessels and tumor cells is also discussed. Finally, the clinical effectiveness of NCs is leading to an increasing number of FDA-approved products, among which the NCs approved for neurological disorders have increased.

Insight into the Loading Properties of Na+ Green-Functionalized Clinoptilolite as a Potential Carrier for the 5-Fluorouracil Drug, its Release Kinetics, and Cytotoxicity

Herein, natural zeolite (clinoptilolite) was functionalized by Na⁺ ions (G.Na⁺/Clino) utilizing a green tea extract prepared by a green production method as a potential carrier for the 5-fluorouracil (5-Fu) drug with enhanced physicochemical behaviors. The G.Na⁺/Clino-modified product showed enhanced surface area (312 m²/g) and ion-exchange capacity (387 mequiv/100 g). The loading studies reflect high and controlled loading properties of G.Na⁺/Clino with an actual loading capacity of 291 and 462 mg/g, respectively. The loading reactions of 5-Fu into G.Na⁺/Clino were of pseudo-second-order kinetics and exhibited Langmuir isotherm properties. This suggested a monolayer and homogeneous loading process by chemical complexation and ion-exchange mechanisms with a Gaussian energy value of 10.47 kJ/mol. Additionally, these reactions were of endothermic and spontaneous nature based on the determined thermodynamic parameters. The release studies demonstrated the 5-Fu release profile for about 150 h at pH 1.2 and for 80 h at pH 7.4. The release reactions had non-Fickian transport properties and were controlled by both erosion and diffusion mechanisms, considering the release kinetic findings and the values of the diffusion exponent (0.42 at pH 1.2 and 0.37 at pH 7.4). The composite showed remarkable biocompatibility based on the measured cell viability and a cytotoxic effect on normal colorectal cells (CCD-18Co). Additionally, the application of G.Na⁺/Clino as an inorganic carrier for the 5-Fu drug prompted the cytotoxic effect of the drug on colon cancer cell treatment (HCT-116).

Biomimetic Citrate-Coated Luminescent Apatite Nanoplatforms for Diclofenac Delivery in Inflammatory Environments

Luminescent nanoparticles are innovative tools for medicine, allowing the imaging of cells and tissues, and, at the same time, carrying and releasing different types of molecules. We explored and compared the loading/release ability of diclofenac (COX-2 antagonist), in both undoped- and luminescent Terbium³⁺ (Tb³⁺)-doped citrate-coated carbonated apatite nanoparticles at different temperatures (25, 37, 40 °C) and pHs (7.4, 5.2). The cytocompatibility was evaluated on two osteosarcoma cell lines and primary human osteoblasts. Biological effects of diclofenac-loaded-nanoparticles were monitored in an in vitro osteoblast’s cytokine–induced inflammation model by evaluating COX-2 mRNA expression and production of PGE₂. Adsorption isotherms fitted the multilayer Langmuir-Freundlich model. The maximum adsorbed amounts at 37 °C were higher than at 25 °C, and particularly when using the Tb³⁺ -doped particles. Diclofenac-release efficiencies were higher at pH 5.2, a condition simulating a local inflammation. The luminescence properties of diclofenac-loaded Tb³⁺ -doped particles were affected by pH, being the relative luminescence intensity higher at pH 5.2 and the luminescence lifetime higher at pH 7.4, but not influenced either by the temperature or by the diclofenac-loaded amount. Both undoped and Tb³⁺-doped nanoparticles were cytocompatible. In addition, diclofenac release increased COX-2 mRNA expression and decreased PGE₂ production in an in vitro inflammation model. These findings evidence the potential of these nanoparticles for osteo-localized delivery of anti-inflammatory drugs and the possibility to localize the inflammation, characterized by a decrease in pH, by changes in luminescence.

Insight into the Technical Qualification of the Sonocogreen CaO/Clinoptilolite Nanocomposite (CaO(NP)/Clino) as an Advanced Delivery System for 5-Fluorouracil: Equilibrium and Cytotoxicity

Clinoptilolite as a natural zeolite was integrated with green CaO nanoparticles forming the green nanocomposite CaO_(NP)/Clino. The CaO_(NP)/Clino composite was assessed as a potential carrier for 5-fluorouracil (5-FL) drug. The CaO_(NP)/Clino carrier achieved an enhanced 5-FL loading capacity of 305.3 mg/g as compared to 163 mg/g for pure clinoptilolite. The kinetics of the 5-FL loading follow the properties of the pseudo-first-order model, while the equilibrium results are related to the Langmuir isotherm. Therefore, the 5-FL loading processes occurred in the monolayer formed by homogeneous active loading receptors on the surface of the CaO_(NP)/Clino carrier. The Gaussian energy of the 5-FL loading reaction (9.2 KJ/mol) reflected the dominant effect for the chemical mechanisms, especially the zeolitic ion-exchange mechanisms. Additionally, the thermodynamic parameters suggested endothermic, feasible, and spontaneous properties for the occurred 5-FL loading reactions. The release profile of 5-FL from CaO_(NP)/Clino has continuous and long properties (150 h) at pH 1.2 (gastric fluid) and pH 7.4 (intestinal fluid). The kinetic studies of the release reactions show considerable agreement with Higuchi, Hixson-Crowell, and Korsmeyer-Peppas models. Such high fitting results and the diffusion exponent values (0.49 at pH 1.2 and 0.48 at pH 7.4) reflected the release properties of the Fickian transport behavior involving complex erosion and diffusion mechanisms. The cytotoxicity study of CaO_(NP)/Clino on colorectal normal cells (CCD-18Co) declare the safe and biocompatible effect as a carrier for the 5-FL drug. Additionally, CaO_(NP)/Clino as a carrier causes considerable enhancement for the cytotoxic effect of the loaded 5-FL drug on colon cancer cells (HCT-116).

Functioned catalysts with magnetic core applied in ibuprofen degradation

In the present work, the performance of Ag/ZnO/CoFe₂O₄ magnetic photocatalysts in the photocatalytic degradation of ibuprofen (IBP) was evaluated. This study considered the use of pure Ag/ZnO (5% Ag) and also the use of the Ag/ZnO/CoFe₂O₄ magnetic catalysts containing different amounts (5, 10 and 15% wt) of cobalt ferrite (CoFe₂O₄). The catalysts were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and photoacoustic spectroscopy. To carry out the photocatalytic degradation reaction, different concentrations of the ibuprofen contaminant solution (10, 20 and 30 ppm) and different concentrations of photocatalyst were tested (0.3 g L^-1, 0.5 g L^-1 and 1.0 g L^-1). The reaction parameters studied were: IBP concentration, catalyst concentration, adsorption and photolysis, influence of the matrix, radiation source (solar and artificial) and the effect of organic additive. At the end of the photocatalytic tests, the best operating conditions were defined. Considering the obtained results of degradation efficiency and magnetic separation, the optimal parameters selected to proceed with the other tests of the study were: ibuprofen solution concentration 10 ppm, Ag/ZnO/CoFe₂O₄ (5%) catalyst at a concentration of 0.3 g L^-1 and pH 4.5 of the reaction medium. The results indicated the feasibility of magnetic separation of the synthesized catalysts. A long duration test indicated that the catalyst exhibits stability throughout the degradation reaction, as more than 80% of IBP was degraded after 300 minutes. The photocatalytic activity was directly affected by the ferrite load. The higher the nominal load of ferrite, the lower the performance in IBP degradation. It was also observed that the smallest amount of ferrite studied was enough for the catalyst to be recovered and reused. The adsorption and photolysis tests did not show significant results in the IBP degradation. In addition, it was possible to verify that the aqueous matrix, the use of solar radiation and the addition of additive (acid formic) were interfered directly in the process. The catalyst reuse tests indicated that it can be recovered and reused at least three times without considerable catalytic activity loss.

Application of UV dissolution imaging to pharmaceutical systems

UV-vis spectrometry is widely used in the pharmaceutical sciences for compound quantification, alone or in conjunction with separation techniques, due to most drug entities possessing a chromophore absorbing light in the range 190-800 nm. UV dissolution imaging, the scope of this review, generates spatially and temporally resolved absorbance maps by exploiting the UV absorbance of the analyte. This review aims to give an introduction to UV dissolution imaging and its use in the determination of intrinsic dissolution rates and drug release from whole dosage forms. Applications of UV imaging to non-oral formulations have started to emerge and are reviewed together with the possibility of utilizing UV imaging for physical chemical characterisation of drug substances. The benefits of imaging drug diffusion and transport processes are also discussed.

Synthesis of Chitosan/Diatomite Composite as an Advanced Delivery System for Ibuprofen Drug; Equilibrium Studies and the Release Profile

Chitosan/diatomite nanocomposite (CS/D) was synthesized as a low-cost and highly porous structure of enhanced physicochemical properties to be applied as advanced carriers for ibuprofen drug (IB). The loading properties of CS/D were studied in comparison to diatomite as a separated phase and achieved a loading capacity of 562.6 mg/g. The loading reactions of IB into CS/D show pseudo-second-order kinetic behavior and Langmuir isotherm properties. This demonstrates homogeneous loading processes in monolayer forms and controlled essentially by physical mechanisms. This was confirmed by the calculated Gaussian energy (7.7 kJ/mol (D) and 7.9 kJ/mol (CS/D)) in addition to the thermodynamic parameters. The thermodynamic behavior for the IB loading process is related to spontaneous, favorable, and exothermic reactions. The CS/D composite is of promising IB release profile that extended to about 200 h with a maximum release of 91.5% at the gastric fluid (pH 1.2) and 97.3% in the intestinal fluid (pH 7.4). The IB release rate from CS/D can be controlled based on the ratio of the integrated chitosan in the composite. The IB release reactions from CS/D follow the assumption of Korsmeyer-Peppas kinetics with determined values for the diffusion exponent reflects complex diffusion and erosion as the affected mechanisms during the IB release process.

Insight into chitosan/zeolite-A nanocomposite as an advanced carrier for levofloxacin and its anti-inflammatory properties; loading, release, and anti-inflammatory studies

Chitosan/zeolite-A nanocomposite (CH/ZA) was synthesized as a potential carrier for levofloxacin (LVOX) of enhanced technical properties. The CH/ZA composite displayed enhanced loading capacity (425 mg/g) as compared to chitosan (188.8 mg/g) and zeolite-A (234.6 mg/g). The loading behavior follows Pseudo-Second-order and Langmuir as kinetic and isotherm models. The equilibrium studies, Gaussian energy (8.15 KJ/mol), and thermodynamic parameters demonstrate homogenous and monolayer loading by complex chemical and physical reactions that are of spontaneous and exothermic nature. The CH/ZA composite is of slow and continuous release profile (200h) with 94.3% as the maximum release percentage. The release reactions are of non-Fickian behavior involving both diffusion and erosion mechanisms. The loading of LVOX into CH/ZA induced its anti-inflammatory effect against the cytokine production (IL-6 and IL-8) within the human bronchial epithelia cells (NL20). The cytotoxicity studies on the normal cells demonstrated a high safety value for the composite.

Synthesis and Characterization of Nano-Sized 4-Aminosalicylic Acid-Sulfamethazine Cocrystals

Drug–drug cocrystals are formulated to produce combined medication, not just to modulate active pharmaceutical ingredient (API) properties. Nano-crystals adjust the pharmacokinetic properties and enhance the dissolution of APIs. Nano-cocrystals seem to enhance API properties by combining the benefits of both technologies. Despite the promising opportunities of nano-sized cocrystals, the research at the interface of nano-technology and cocrystals has, however, been described to be in its infancy. In this study, high-pressure homogenization (HPH) and high-power ultrasound were used to prepare nano-sized cocrystals of 4-aminosalysilic acid and sulfamethazine in order to establish differences between the two methods in terms of cocrystal size, morphology, polymorphic form, and dissolution rate enhancement. It was found that both methods resulted in the formation of form I cocrystals with a high degree of crystallinity. HPH yielded nano-sized cocrystals, while those prepared by high-power ultrasound were in the micro-size range. Furthermore, HPH produced smaller-size cocrystals with a narrow size distribution when a higher pressure was used. Cocrystals appeared to be needle-like when prepared by HPH compared to those prepared by high-power ultrasound, which had a different morphology. The highest dissolution enhancement was observed in cocrystals prepared by HPH; however, both micro- and nano-sized cocrystals enhanced the dissolution of sulfamethazine.