Development of curcumin nanocrystal: physical aspects

Reduction of biofilm and pathogenic microorganisms using curcumin-mediated photodynamic inactivation to prolong food shelf-life

Pathogenic microbial contamination (bacteria and fungi) in food products during production poses a significant global health risk, leading to food waste, greenhouse gas emissions, and aesthetic and financial losses. Bacteria and fungi, by forming solid biofilms, enhance their resistance to antimicrobial agents, thereby increasing the potential for cross-contamination of food products. Curcumin molecule-mediated photodynamic inactivation (Cur-m-PDI) technology has shown promising results in sterilizing microbial contaminants and their biofilms, significantly contributing to food preservation without compromising quality. Photosensitizers (curcumin) absorb light, leading to a chemical reaction with oxygen and producing reactive oxygen species (ROS) that effectively reduce bacteria, fungi, and biofilms. The mechanism of microorganism inhibition is caused by exposure to ROS generated via the type 1 pathway involving electron transfer (such as O2•-, H2O2, -OH•, and other radicals), the type 2 pathway involving energy transfer (such as 1O2), secondary ROS, and weakening of antioxidant enzymes. The effectiveness of the inactivation of microorganisms is influenced by the concentration of curcumin, light (source type and energy density), oxygen availability, and duration of exposure. This article reviews the mechanism of reducing microbial food contamination and inhibiting their biofilms through Cur-m-PDI. It also highlights future directions, challenges, and considerations related to the effects of ROS in oxidizing food, the toxicity of PDI to living cells and tissues, conditions/types of food products, and the stability and degradation of curcumin.

Controlled preparation of curcumin nanocrystals by detachable stainless steel microfluidic chip

Microfluidic technology has not been extensively utilized in nanocrystals manufacture, although it has been used in the production of liposomes and LNPs. This is mainly due to concerns including blockage of narrow pipes and corrosion of organic solvents on chips. In this study, a detachable stainless steel microfluidic chip with split-and-recombine (SAR) structure was engraved and used to prepare curcumin nanocrystal suspensions by a microfluidic-antisolvent precipitation method. A simulation study of the mixing activities of three chip structures was conducted by COMSOL Multiphysics software. Then the curcumin nanocrystals preparation was optimized by Box-Behnken design to screen different stabilizers and solvents. Two curcumin nanocrystals formulations with an average particle size of 59.29 nm and 168.40 nm were obtained with PDIs of 0.131 and 0.058, respectively. Compared to curcumin powder, the formulation showed an increase in dissolution rate in 0.1 M HCL while pharmacokinetic study indicated that Cmax was increased by 4.47 and 3.14 times and AUC0-∞ were 4.26 and 3.14 times greater. No clogging or deformation of the chip was observed after long usage. The results demonstrate that the stainless steel microfluidic chips with SAR structure have excellent robustness and controllability. It has the potential to be applied in GMP manufacturing of nanocrystals.

The regulating effect of curcumin on NF-κB pathway in neurodegenerative diseases: a review of the underlying mechanisms

Neurodegenerative diseases are part of the central nervous system (CNS) disorders that indicate their presence with neuronal loss, neuroinflammation, and increased oxidative stress. Several pathophysiological factors and biomarkers are involved in this inflammatory process causing these neurological disorders. The nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) is an inflammation element, which induced transcription and appears to be one of the important players in physiological procedures, especially nervous disorders. NF-κB can impact upon series of intracellular actions and induce or inhibit many inflammation-related pathways. Multiple reports have focused on the modification of NF-κB activity, controlling its expression, translocation, and signaling pathway in neurodegenerative disorders and injuries like Alzheimer's disease (AD), spinal cord injuries (SCI), and Parkinson's disease (PD). Curcumin has been noted to be a popular anti-oxidant and anti-inflammatory substance and is the foremost natural compound produced by turmeric. According to various studies, when playing an anti-inflammatory role, it interacts with several modulating proteins of long-standing disease signaling pathways and has an unprovocative consequence on pro-inflammatory cytokines. This review article determined to figure out curcumin's role in limiting the promotion of neurodegenerative disease via influencing the NF-κB signaling route. Preclinical studies were gathered from plenty of scientific platforms including PubMed, Scopus, Cochrane, and Google Scholar to evaluate this hypothesis. Extracted findings from the literature review explained the repressing impact of Curcumin on the NF-κB signaling pathway and, occasionally down-regulating the cytokine expression. Yet, there is an essential need for further analysis and specific clinical experiments to fully understand this subject.

Folic Acid-Decorated Nanocrystals as Highly Loaded Trojan Horses to Target Cancer Cells

The nanocrystal (NC) technology has become one of the most commonly used strategies for the formulation of poorly soluble actives. Given their large specific surface, NCs are mainly used to enhance the oral absorption of poorly soluble actives. Differently from conventional nanoparticles, which require the use of carrier materials and have limited drug loadings, NCs' drug loading approaches 100% since they are formed of the pure drug and surrounded by a thin layer of a stabilizer. In this work, we report the covalent decoration of curcumin NCs with folic acid (FA) using EDC/NHS chemistry and explore the novel systems as highly loaded "Trojan horses" to target cancer cells. The decorated NCs demonstrated a remarkable improvement in curcumin uptake, exhibiting enhanced growth inhibition in cancer cells (HeLa and MCF7) while sparing healthy cells (J774A.1). Cellular uptake studies revealed significantly heightened entry of FA-decorated NCs into cancer cells compared to unmodified NCs while also showing reduced uptake by macrophages, indicating a potential for prolonged circulation in vivo. These findings underline the potential of NC highly loaded nanovectors for drug delivery and, in particular, for cancer therapies, effectively targeting folate receptor-overexpressing cells while evading interception by macrophages, thus preserving their viability and offering a promising avenue for precise and effective treatments.

Recent developments in the use of nanocrystals to improve bioavailability of APIs

Nanocrystals refer to materials with at least one dimension smaller than 100 nm, composing of atoms arranged in single crystals or polycrystals. Nanocrystals have significant research value as they offer unique advantages over conventional pharmaceutical formulations, such as high bioavailability, enhanced targeting selectivity and controlled release ability and are therefore suitable for the delivery of a wide range of drugs such as insoluble drugs, antitumor drugs and genetic drugs with broad application prospects. In recent years, research on nanocrystals has been progressively refined and new products have been launched or entered the clinical phase of studies. However, issues such as safety and stability still stand that need to be addressed for further development of nanocrystal formulations, and significant gaps do exist in research in various fields in this pharmaceutical arena. This paper presents a systematic overview of the advanced development of nanocrystals, ranging from the preparation approaches of nanocrystals with which the bioavailability of poorly water-soluble drugs is improved, critical properties of nanocrystals and associated characterization techniques, the recent development of nanocrystals with different administration routes, the advantages and associated limitations of nanocrystal formulations, the mechanisms of physical instability, and the enhanced dissolution performance, to the future perspectives, with a final view to shed more light on the future development of nanocrystals as a means of optimizing the bioavailability of drug candidates. This article is categorized under: Therapeutic Approaches and Drug Discovery > Emerging Technologies Nanotechnology Approaches to Biology > Nanoscale Systems in Biology.

A quality by design framework for developing nanocrystal bioenabling formulations

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

Nanosuspension-based microneedle skin patch of baclofen for sustained management of multiple sclerosis-related spasticity

Baclofen (BAC) is the first-line recommendation to treat spasticity in people with multiple sclerosis whose treatment goals include improving mobility or easing pain. The short half-life of BAC calls for multiple daily dosing which may be eliminated by the development of a transdermal system. This study aimed to assess the effect of transdermal microneedle patches on improving the skin permeation of BAC. Nanosuspension-loaded microneedle patch containing BAC was fabricated and characterized. In vitro permeation of BAC across intact and microneedle-treated dermatomed porcine ear skin was evaluated. In vitro passive permeation of BAC solution after 72 h was observed to be 92.56 ± 11.24 µg/cm2. A near 9-fold enhancement was observed when employing the strategy of microneedle-mediated delivery of the solution. To increase drug loading, two strategies, nanosizing and microneedle-mediated delivery, were combined and permeation of BAC after 72 h resulted to be 1951.95 ± 82.01 µg/cm2 (p < 0.05). Microneedle-mediated transdermal delivery of BAC holds potential for sustained management of multiple sclerosis-related spasticity. Nanosizing of BAC particles facilitated higher drug loading in MN patches and an eventual increase in cumulative drug permeation from the patches.

The State of the Art of Natural Polymer Functionalized Fe3O4 Magnetic Nanoparticle Composites for Drug Delivery Applications: A Review

Natural polymers have received a great deal of interest for their potential use in the encapsulation and transportation of pharmaceuticals and other bioactive compounds for disease treatment. In this perspective, the drug delivery systems (DDS) constructed by representative natural polymers from animals (gelatin and hyaluronic acid), plants (pectin and starch), and microbes (Xanthan gum and Dextran) are provided. In order to enhance the efficiency of polymers in DDS by delivering the medicine to the right location, reducing the medication's adverse effects on neighboring organs or tissues, and controlling the medication's release to stop the cycle of over- and under-dosing, the incorporation of Fe3O4 magnetic nanoparticles with the polymers has engaged the most consideration due to their rare characteristics, such as easy separation, superparamagnetism, and high surface area. This review is designed to report the recent progress of natural polymeric Fe3O4 magnetic nanoparticles in drug delivery applications, based on different polymers' origins.

The Effect of Curcumin Nanoparticles on Paracetamol-induced Liver Injury in Male Wistar Rats

INTRODUCTION

Curcumin is a naturally occurring compound that has antioxidant properties, acts as a hepatoprotective, and lowers lipid peroxidation. However, curcumin's low solubility and bioavailability are its primary drawbacks and prevent its use as a therapeutic agent. In this study, curcumin nanoparticles will be created using the ultrasonic-assisted extraction method, and their effectiveness against paracetamol-induced changes in ALT, AST, SOD, MDA, and TNF-α will be compared to that of pure curcumin.

PURPOSE

This study aimed to determine the hepatoprotective effect of curcumin nanoparticles in paracetamol- induced rats as a model for liver injury.

METHODS

Thirty-six male Wistar rats, aged 6 to 8 weeks, with a minimum weight of 120 grams, were used in an experimental laboratory investigation with a post-test-only group design. Rats in each group received 100 mg/kgBW pure curcumin, 100 mg/kgBW curcumin nanoparticles, and 50 mg/kgBW curcumin nanoparticles for 7 days before paracetamol induction. On day 8, 300 mg/kgBW of paracetamol was intraperitoneally injected to cause liver damage. One of the groups received NAC as an antidote 10 hours after paracetamol induction. Detection of ALT and AST using a Chemistry Analyzer. ELISA approach for the detection of SOD, MDA, and TNF-α. The Roenigk score was calculated by two examiners after the liver histopathology preparations were stained using the Hematoxylin-Eosin method. Post hoc analyses were performed after the One Way Annova and Kruskal Wallis tests to examine the data.

RESULTS

According to PSA results, the smallest formula that formed curcumin nanoparticles (10.2 nm) was 8 g of curcumin formula mixed with a mixture of Tween 20 4.5 ml, Kolliphor EL 1.5 ml, Propylene Glycol 1.5 ml, and Capryol 90 1 ml for 21 minutes using an ultrasonic process. MDA and TNF-α levels, as well as the liver's histological Roenigk score, were significantly lower in the 100 mg/kgBB pure curcumin group (C100) when compared to the model group (model). The levels of AST, MDA, TNF-α, and the liver histopathology score were significantly lower in the 100 mg/kgBB (NC100) and 50 mg/kgBB (NC50) curcumin nanoparticle groups compared to the model group (model) and pure curcumin group (C100) (p< 0.05).

CONCLUSION

Curcumin nanoparticles showed better hepatoprotective ability than pure curcumin.

The theranostic potentialities of bioavailable nanocurcumin in oral cancer management

BACKGROUND

Oral cancer, one of the most common cancers, has unimproved 5-years survival rate in the last 30 years and the chemo/radiotherapy-associated morbidity. Therefore, intervention strategies that evade harmful side effects of the conventional treatment modalities are of need. Herbal therapy as a complementary preventive/therapeutic modality has gained attention. Curcumin is one of the herbal compounds possessing unique anticancer activity and luminescent optical properties. However, its low water solubility limits its efficacy. In contrast, curcumin at the nanoscale shows altered physical properties with enhancing bioavailability.

METHODS

The current study evaluated the impact of nanocurcumin as an anti-oral cancer herbal remedy, comparing its efficacy against the native curcumin complement and conventional chemotherapeutic. An optimized polymeric-stabilized nanocurcumin was synthesized using the solvent-antisolvent precipitation technique. After assuring the solubility and biocompatibility of nanocurcumin, we determined its cytotoxic dose in treating the squamous cell carcinoma cell line. We then evaluated the anti-tumorigenic activity of the nano-herb in inhibiting wound closure and the cytological alterations of the treated cancer cells. Furthermore, the cellular uptake of the nanocurcumin was assessed depending on its autofluorescence.

RESULTS

The hydrophilic optimized nanocurcumin has a potent cancerous cytotoxicity at a lower dose (60.8 µg/mL) than the native curcumin particles (212.4 µg/mL) that precipitated on high doses hindering their cellular uptake. Moreover, the nanocurcumin showed differential targeting of the cancer cells over the normal fibroblasts with a selectivity index of 4.5. With the confocal microscopy, the luminescent nanoparticles showed gradual nuclear and cytoplasmic uptake with apparent apoptotic cell death, over the fluorescent doxorubicin with its necrotic effect. Furthermore, the nanocurcumin superiorly inhibited the migration of cancer cells by -25%.

CONCLUSIONS

The bioavailable nanocurcumin has better apoptotic cytotoxicity. Moreover, its superior luminescence promotes the theranostic potentialities of the nano-herb combating oral cancer.

Curcumin-Loaded Microspheres Are Effective in Preventing Oxidative Stress and Intestinal Inflammatory Abnormalities in Experimental Ulcerative Colitis in Rats

Curcumin’s role in the treatment of ulcerative colitis (UC) has been proven by numerous studies, but its preventive administration, with the aim of reducing the remission episodes that are characteristic of this disease, must be further investigated. This study investigates the effects of a novel curcumin-loaded polymeric microparticulate oral-drug-delivery system for colon targeting (Col-CUR-MPs) in an experimental model of UC. Male Wistar rats (n = 40) were divided into five groups (n = 8), which were treated daily by oral gavage for seven days with a 2% aqueous solution of carboxymethylcellulose sodium salt (CMCNa) (healthy and disease control), free curcumin powder (reference), Col-CUR-MPs (test) and prednisolone (reference) prior to UC induction by the intrarectal administration of acetic acid (AA), followed by animal sacrification and blood and colonic samples’ collection on the eighth day. Col-CUR-MPs exhibited an important preventive effect in the severity degree of oxidative stress that resulted following AA intrarectal administration, which was proved by the highest catalase (CAT) and total antioxidant capacity (TAC) levels and the lowest nitrites/nitrates (NOx), total oxidative status (TOS) and oxidative stress index (OSI) levels. Biochemical parameter analysis was supported by histopathological assessment, confirming the significant anti-inflammatory and antioxidant effects of this novel colon-specific delivery system in AA-induced rat models of UC. Thus, this study offers encouraging perspectives regarding the preventive administration of curcumin in the form of a drug delivery system for colon targeting.

Curcumin-loaded hydroxypropyl-β-cyclodextrin inclusion complex with enhanced dissolution and oral bioavailability for epilepsy treatment

Curcumin, the main bioactive component of turmeric, has a wild range of beneficial effects on central nervous diseases, including anti-Alzheimer's disease, antioxidant stress, and anti-inflammation. Currently, it has been demonstrated the anti-epileptic potential. However, curcumin has poor water solubility, high sensitivity to light and heat, and low absorption, which results in low bioavailability and greatly limits the clinical application of curcumin, as well as the elusive effects in anti-epileptic treatment.This study aimed to develop a curcumin hydroxypropyl-β-cyclodextrin inclusion complex (CUR-HP-β-CD) to improve its bioavailability and facilitate its potential development as an anti-epileptic drug. The CUR-HP-β-CD was generated by the solvent evaporation method, which has efficient entrapment, high solubility, and facilitated bioavailability and brain distribution.The solubility of the CUR-HP-β-CD was 63.5, 60.1, and 52.9 times that of the unformulated curcumin in H₂O, HCl (pH 1.2), and PBS (pH 6.8), respectively. The bioavailability of CUR-HP-β-CD is improved 2.8 times and 38.7 folds higher brain concentrations. Moreover, the therapeutic anti-epileptic effects of CUR-HP-β-CD were much more effective in pentylenetetrazol (PTZ)-induced zebrafish and mouse models.This study showed a simple and reproducible strategy to effectively improve the bioavailability and therapeutic effects of curcumin, which could be potentially used in epilepsy treatment.

Fabrication and Characterization of Tedizolid Phosphate Nanocrystals for Topical Ocular Application: Improved Solubilization and In Vitro Drug Release

Positively charged NCs of TZP (0.1%, w/v) for ocular use were prepared by the antisolvent precipitation method. TZP is a novel 5-Hydroxymethyl-Oxazolidinone class of antibiotic and is effective against many drug-resistant bacterial infections. Even the phosphate salt of this drug is poorly soluble, therefore the NCs were prepared for its better solubility and ocular availability. P188 was found better stabilizer than PVA for TZP-NCs. Characterization of the NCs including the particle-size, PDI, and ZP by Zeta-sizer, while morphology by SEM indicated that the preparation technique was successful to get the optimal sized (151.6 nm) TZP-NCs with good crystalline morphology. Mannitol (1%, w/v) prevented the crystal growth and provided good stabilization to NC₁ during freeze-drying. FTIR spectroscopy confirmed the nano-crystallization did not alter the basic molecular structure of TZP. DSC and XRD studies indicated the reduced crystallinity of TZP-NC₁, which potentiated its solubility. An increased solubility of TZP-NC₁ (25.9 µgmL⁻¹) as compared to pure TZP (18.4 µgmL⁻¹) in STF with SLS. Addition of stearylamine (0.2%, w/v) and BKC (0.01%, w/v) have provided cationic (+29.4 mV) TZP-NCs. Redispersion of freeze-dried NCs in dextrose (5%, w/v) resulted in a clear transparent aqueous suspension of NC₁ with osmolarity (298 mOsm·L⁻¹) and viscosity (21.1 cps at 35 °C). Mannitol (cryoprotectant) during freeze-drying could also provide isotonicity to the nano-suspension at redispersion in dextrose solution. In vitro release in STF with SLS has shown relatively higher (78.8%) release of TZP from NC₁ as compared to the conventional TZP-AqS (43.4%) at 12 h. TZP-NC₁ was physically and chemically stable at three temperatures for 180 days. The above findings suggested that TZP-NC₁ would be a promising alternative for ocular delivery of TZP with relatively improved performance.

Drug Nanocrystals for Active Tumor-Targeted Drug Delivery

Drug nanocrystals, which are comprised of active pharmaceutical ingredients and only a small amount of essential stabilizers, have the ability to improve the solubility, dissolution and bioavailability of poorly water-soluble drugs; in turn, drug nanocrystal technology can be utilized to develop novel formulations of chemotherapeutic drugs. Compared with passive targeting strategy, active tumor-targeted drug delivery, typically enabled by specific targeting ligands or molecules modified onto the surface of nanomedicines, circumvents the weak and heterogeneous enhanced permeability and retention (EPR) effect in human tumors and overcomes the disadvantages of nonspecific drug distribution, high administration dosage and undesired side effects, thereby contributing to improving the efficacy and safety of conventional nanomedicines for chemotherapy. Continuous efforts have been made in the development of active tumor-targeted drug nanocrystals delivery systems in recent years, most of which are encouraging and also enlightening for further investigation and clinical translation.

Spatial-thermodynamic understanding of stabilization mechanism using computational approaches and molecular-level elucidation of the mechanism of crystal transformation in polymorphic irbesartan nanosuspensions

Irbesartan polymorphisms possess low solubility properties, nanosuspensions represent a method for improving the dissolution. Stabilizers are significant constituents of nanosuspensions. Herein we presented computational research on screening stabilizers and exploring stabilization mechanisms. The crystal transformation mechanism was also investigated. Soluplus-P407 and TPGS-HPMCE5 were screened by spatial conformation and thermodynamic energy analyses. The prepared nanosuspensions improved the dissolution properties of bulk drugs at pH 1.2, 4.5, 6.8. The nanosuspensions stabilization mechanism was analyzed by Molecular docking, Molecular dynamics simulations, Fourier transform infrared spectroscopy and Raman spectroscopy. It might be relate to the decreased enthalpy and Gibbs free energy which were determined by the synergy of external and internal energy factors. The X-ray powder diffraction, differential scanning calorimetry, scanning electron microscopy and transmission electron microscopy showed the crystal structures. The irbesartan B form was transformed in a Soluplus-P407-B/TPGS-HPMCE5-B physical mixture, but not in an SDS (-OH free)-B physical mixture. The intra-proton transfer induced by -OH on the stabilizer might be the transformation mechanism.

Curcumin Nanoparticles Enhance Antioxidant Efficacy of Diclofenac Sodium in Experimental Acute Inflammation

We investigated the in vivo effect of curcumin nanoparticles (nC) in addition to diclofenac sodium on local edema and oxidative stress parameters in carrageenan-induced paw edema on rats. Seven groups were investigated: control group (C), the acute inflammation (AI) group, an AI group treated with Diclofenac (AID, 5 mg/kg b.w. Diclofenac sodium), two AI groups treated with cC (conventional Curcumin)—AIC200 and AIcC200D (D = Diclofenac, 200 represent the concentration of active substance expressed in mg/kg b.w.), and two AI groups with nC (Curcumin nanoparticles)—AIC200 and AIcC200D. Serum and tissue oxidative stress was assessed by measuring five parameters. Curcumin nanoparticles alone and in combination with D better reduced the paw edema than D alone (p < 0.027). The rats treated with D and nC (AIcC200D) had the highest inhibition percentage on edema, reaching the maximum level of inhibition (81%) after 24 h. Conventional curcumin and nC presented antioxidant effects in acute inflammation, with significantly better results obtained for nC. The pro-oxidant markers were reduced up to 0.3 by the cC and up to 0.4 times by the nC and both solutions increased the antioxidant markers up to 0.3 times. The nC enhanced the antioxidative efficacy of D, as this combination reduced the pro-oxidant markers up to 1.3 times. Curcumin nanoparticles could represent a therapeutic option in association with classical nonsteroidal anti-inflammatory medication in acute inflammation, as they might offer a reduction of drug dose and possible limitation of their associated side effects.

Drug Delivery Strategies for Curcumin and Other Natural Nrf2 Modulators of Oxidative Stress-Related Diseases

Oxidative stress is associated with a wide range of diseases characterised by oxidant-mediated disturbances of various signalling pathways and cellular damage. The only effective strategy for the prevention of cellular damage is to limit the production of oxidants and support their efficient removal. The implication of the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway in the cellular redox status has spurred new interest in the use of its natural modulators (e.g., curcumin, resveratrol). Unfortunately, most natural Nrf2 modulators are poorly soluble and show extensive pre-systemic metabolism, low oral bioavailability, and rapid elimination, which necessitates formulation strategies to circumvent these limitations. This paper provides a brief introduction on the cellular and molecular mechanisms involved in Nrf2 modulation and an overview of commonly studied formulations for the improvement of oral bioavailability and in vivo pharmacokinetics of Nrf2 modulators. Some formulations that have also been studied in vivo are discussed, including solid dispersions, self-microemulsifying drug delivery systems, and nanotechnology approaches, such as polymeric and solid lipid nanoparticles, nanocrystals, and micelles. Lastly, brief considerations of nano drug delivery systems for the delivery of Nrf2 modulators to the brain, are provided. The literature reviewed shows that the formulations discussed can provide various improvements to the bioavailability and pharmacokinetics of natural Nrf2 modulators. This has been demonstrated in animal models and clinical studies, thereby increasing the potential for the translation of natural Nrf2 modulators into clinical practice.

Rod-shaped nintedanib nanocrystals improved oral bioavailability through multiple intestinal absorption pathways

Nintedanib (BIBF) is a biopharmaceutical classification system II (BCS II) drug that has a good therapeutic effect for the treatment of nonsmall cell lung cancer; however, it shows poor oral bioavailability due to low dissolution and intestinal absorption. This study aims to fabricate rod-shaped nanocrystals to enhance oral bioavailability by improving the dissolution and absorption of BIBF in the intestine. By prescription screening, BIBF nanocrystals (BIBF-NCs) with a particle size of 325.30 ± 1.03 nm and zeta potential of 32.70 ± 1.24 mV were fabricated by an antisolvent precipitation-ultrasound approach with a stabilizer of sodium carboxyl methyl cellulose (CMC-Na). BIBF-NCs exhibited a rod-shaped morphology by transmission electron microscopy (TEM). The results of powder X-ray diffraction (PXRD) and differential scanning calorimetry (DSC) showed that the crystal form of BIBF in BIBF-NCs was altered. The BIBF-NCs remarkably improved the saturation solubility and dissolution of BIBF compared with BIBF powder. According to the results of in situ single-pass intestinal perfusion (SPIP), BIBF-NCs showed improved absorption and membrane permeability, with K_a and P_app values in the jejunum of 0.21 ± 0.01 min^-1 and (4.34 ± 0.11) × 10^-4 cm/min, respectively. Further, the K_a and P_app values of BIBF-NCs were all reduced significantly after the addition of inhibitors colchicine, chlorpromazine and indomethacin, which demonstrated that BIBF-NCs could be absorbed by endocytosis mediated by caveolae and clathrin and micropinocytosis in the intestine. The cell evaluation results showed that BIBF-NCs could be taken up by macrophages and transported from Caco-2 monolayers. The in vivo pharmacokinetic results showed that the bioavailability of the BIBF-NCs was 2.51-fold higher than that of the BIBF solution (BIBF-Sol) after oral administration with a longer T_max (4.50 ± 1.00 h vs. 2.60 ± 1.92 h). In summary, rod-shaped BIBF-NCs could significantly improve oral bioavailability through multiple intestinal absorption pathways.

The Influence of Silver Nanoparticles Against Toxic Effects of Philodryas olfersii Venom

Purpose

A silver nanoparticle obtained by reducing salts with solid dispersion of curcumin (130 nm, 0.081 mg mL⁻¹) was used to counteract against the toxic – edematogenic, myotoxic, and neurotoxic – effects of Philodryas olfersii venom.

Methods

The edematogenic effect was evaluated by plasma extravasation in rat dorsal skin after injection of 50 µg per site of venom alone or preincubated with 1, 10, and 100 µL of AgNPs; the myotoxicity was evaluated by measuring the creatine kinase released into the organ-bath before the treatment and at the end of each experiment; and neurotoxicity was evaluated in chick biventer cervicis using the conventional myographic technique, face to the exogenous acetylcholine (ACh) and potassium chloride (KCl) added into the bath before the treatment and after each experiment. Preliminarily, a concentration-response curve of AgNPs was carried out to select the concentration to be used for neutralizing assays, which consists of neutralizing the venom-induced neuromuscular paralysis and edema by preincubating AgNPs with venom for 30 min.

Results

The P. olfersii venom-induced edema (n=6) and a complete neuromuscular blockade (n=4) that includes the total and unrecovered block of ACh and KCl contractures. AgNPs produced a concentration-dependent decrease the venom-induced edema (n=6) from 223.3% to 134.4% and to 100.5% after 10 and 100 µL AgNPs-preincubation, respectively. The preincubation of venom with AgNPs (1 µL; n=6) was able to maintain 46.5 ± 10.9% of neuromuscular response under indirect stimuli, 39.2 ± 9.7% of extrinsic nicotinic receptors functioning in absence of electrical stimulus and 28.3 ± 8.1% of responsiveness to potassium on the sarcolemmal membrane. The CK release was not affected by any experimental protocol which was like control.

Conclusion

AgNPs interact with constituents of P. olfersii venom responsible for the edema-forming activity and neuromuscular blockade, but not on the sarcolemma membrane-acting constituents. The protective effect of the studied AgNPs on avian preparation points out to molecular targets as intrinsic and extrinsic nicotinic receptors.

Improving stability and oral bioavailability of hydroxycamptothecin via nanocrystals in microparticles (NCs/MPs) technology

This study developed a nanocrystals-in-microparticles (NCs/MPs) technology for improving dissolution and oral absorption of poorly soluble drugs. Hydroxycamptothecin (HCPT) was selected as a model drug and prepared to be nanocrystals (HCPT-NCs) by acid-alkali based precipitation. The HCPT-NCs were rod like shape with the length of 250 nm and the width of 50 nm. Then, the chitosan and sodium alginate were selected as microparticles matrix to encapsulate the HCPT-NCs. The HCPT-NCs were entrapped in microparticles with a D₅₀ value of 15 µm. The drug loading capacity of microparticles achieved more than 40% (w/w) by NCs/MPs technology. The powder X-ray diffraction showed the crystal structure of HCPT in microparticles was same as nanocrystals, indicating that the preparation of microparticles could not destroy the nanocrystals. The in vitro release demonstrated that microparticles could protect the NCs in gastric fluid and release NCs in intestinal fluid. Furthermore, the oral bioavailability of HCPT in NCs/MPs was improved by 18-fold compared to bulk HCPT and 2.1-fold compared to HCPT-NCs as tested by a rat model. Therefore, NCs/MPs technology is a promising and high effective approach to improve the oral bioavailability of poorly soluble drugs.

Quality by design prospects of pharmaceuticals application of double emulsion method for PLGA loaded nanoparticles

Abstract

QbD approach empowers the pharma researchers to minimize the number of experimental trials and time. It helps identify the significant, influential factors such as critical material attributes, critical formulation variables, and critical process parameters, which may significantly impact the quality of the products. Poly lactic-co-glycolic acid (PLGA), a biocompatible and biodegradable polymer, has gained an immense potential and wide range of applications as a carrier for manufacturing of polymeric nanoparticle drug delivery systems as per US-FDA and European Medicine Agency for drug delivery. The double emulsion method for preparing PLGA nanoparticles to encapsulate hydrophilic drugs has attracted interest in manufacturing processes. The double emulsion is a two-step process consisting of two different emulsification, making the process more complicated. The stability of nanoparticles obtained by a double emulsion method remains questionable due to the many formulations and process attributes. Currently, PLGA based nanoparticles prepared by a double emulsion technique are an alternative pharmaceutical manufacturing operation for getting the quality product by employing the Quality by Design approach. This present review has discussed the QbD elements to elucidate the effect of material attributes, formulation, and process variables on the critical quality attributes of the drug product, such as particle size distribution, encapsulation efficiency, etc. The components of a double emulsion, characteristics of drugs, polymers, and stabilizers used have been discussed in detail in this review.

Graphic abstract

Curcumin micelles entrapped in eudragit S-100 matrix: a synergistic strategy for enhanced oral delivery

Background:

Therapeutic activities of curcumin (CUR) via oral administration are hampered by the lack of bioavailability due to its poor water solubility and rapid degradation in GI tract.

Materials & methods:

This preliminary study developed CUR micelle-eudragit S100 (EUD) dry powder (CM-EDP) spray-dried formulations. Poloxamer 407 was used as a micelle-forming agent and EUD as an entrapping matrix for protection over hydrolysis and enzymes in the GI tract.

Results:

The morphology of CM-EDP showed agglomeration with cratering on the surface of particles. Differential thermal analysis and x-ray diffractometry data exhibited evidence that CUR was converted into amorphous solid. An increased concentration of micelle-forming and dispersion matrix polymers resulted in a high fraction of drug being converted into the amorphous state. A significant increase in dissolution by 7–10 times was achieved compared with that of raw CUR.

Conclusion:

The present study disclosed the CM-EDP potency for future development of CUR oral formulation.

Curcumin (CUR) is a natural compound that shows several pharmacological activities, including anti-inflammatory and potential actions against Parkinson’s and Alzheimer’s. However, several drawbacks need to be addressed its application as a therapeutic agent via oral administration. These drawbacks include its poor water solubility and rapid degradation in the GI tract. The present study developed CUR micelle-eudragit S100 (EUD) dry powder formulation involving poloxamer 407 as solubilizing agent and EUD as entrapping matrix for protection in acidic environments and the enzymes in the GI tract. The final product is in the form of dry powder, which showed potency in enhancing CUR absorption following oral administration.

Curcumin Loaded and Co-loaded Nanosystems: A Review from a Biological Activity Enhancement Perspective

BACKGROUND

Curcumin is a natural phenolic compound exhibiting multiple bioactivities that have been evaluated in vitro, in vivo as well as through clinical studies in humans. Some of them include antimicrobial, antioxidant, anti-inflammatory, and central nervous system protective effects. Further, curcumin is generally recognized as a safe substance because of its low toxicity. However, its molecular structure is susceptible to changes in pH, oxidation, photodegradation, low aqueous solubility, and biotransformation compromising its bioavailability; these drawbacks are successfully addressed through nanotechnology.

OBJECTIVE

The present review systematizes findings on the enhancement of curcumin's beneficial effects when it is loaded and co-loaded into different types of nanosystems covering liposomes, polymeric and solid-lipid nanoparticles, nanostructured lipid carrier, lipid-polymeric hybrids, self- -assembled and protein-based core-shell systems in relation to its antimicrobial, antioxidant, anti-inflammatory and central nervous system protective bioactivities.

CONCLUSION

Curcumin is a versatile molecule capable of exerting antimicrobial, antioxidant, anti- inflammatory, and central nervous system protective effects in an enhanced manner using the possibilities offered by the nanotechnology-based approach. Its enhanced bioactivities are associated with increments in solubility, stability, bioavailability, as well as in improved intracellular uptake and cell internalization. These advantages, in addition to curcumin's low toxicity, indicate the potential of curcumin to be loaded and co-loaded into nanosystems capable of providing a controlled release and targeted administration.

Curcumin Metabolite Tetrahydrocurcumin in the Treatment of Eye Diseases

Curcumin is one of the most valuable natural products due to its pharmacological activities. However, the low bioavailability of curcumin has long been a problem for its medicinal use. Large studies have been conducted to improve the use of curcumin; among these studies, curcumin metabolites have become a relatively new research focus over the past few years. Additionally, accumulating evidence suggests that curcumin or curcuminoid metabolites have similar or better biological activity than the precursor of curcumin. Recent studies focus on the protective role of plasma tetrahydrocurcumin (THC), a main metabolite of curcumin, against tumors and chronic inflammatory diseases. Nevertheless, studies of THC in eye diseases have not yet been conducted. Since ophthalmic conditions play a crucial role in worldwide public health, the prevention and treatment of ophthalmic diseases are of great concern. Therefore, the present study investigated the antioxidative, anti-inflammatory, antiangiogenic, and neuroprotective effects of THC on four major ocular diseases: age-related cataracts, glaucoma, age-related macular degeneration (AMD), and diabetic retinopathy (DR). While this study aimed to show curcumin as a promising potential solution for eye conditions and discusses the involved mechanistic pathways, further work is required for the clinical application of curcumin.

Endogenous antioxidant properties of curcuminoids from Curcuma longa L. obtained by a single-step extraction/nanoencapsulation approach

Curcuminoids found in turmeric have attracted attention due to their remarkable biological activity. Nanoencapsulation may improve their technological properties, but extraction and encapsulation procedures could be time-consuming and expensive when carried out separately. This work aimed to combine extraction and nanoencapsulation steps to obtain curcuminoids-polyvinylpyrrolidone (PVP) nanoparticles directly from plant rhizomes. This single-step procedure was evaluated by a Rotatable Central Composite Design (RCCD) and optimized using desirability functions, resulting in the optimal conditions of temperature (29.9°C), ethanol (99%), and PVP (15.38 mg). Nanoencapsulation allowed curcuminoids to exert scavenging activity against superoxide anions donors and hydrogen peroxide in an aqueous medium, despite their poor water solubility. Curcuminoids-PVP nanoparticles could be used to formulate nutraceutical foods as an adjuvant to the endogenous antioxidant defense systems protecting against cellular damage. PRACTICAL APPLICATION: Simultaneous extraction and nanoencapsulation of curcuminoids from turmeric (Curcuma longa L.) was studied in this work. The combination of two processes in one single step reduces production time and costs, enhancing the feasibility of curcuminoids microparticles application into foodstuff. Moreover, since most foodstuff presents water in their composition, increase of curcuminoids water dispersibility could facilitate their incorporation into food matrices and improve the use of their health benefits, as results from this research demonstrated that encapsulated curcuminoids were able to scavenge reactive oxygen species in aqueous medium, even though they are lipophilic compounds.

Hair follicle targeting with curcumin nanocrystals: Influence of the formulation properties on the penetration efficacy

Nanocrystals are a universal formulation approach for improved drug delivery of poorly water-soluble drug substances. Besides oral application, also topical application of the nanocrystals is feasible, because the increased kinetic solubility of the nanocrystals results in an increased concentration gradient, thus fostering passive, dermal penetration. Nanocrystals are also promising for targeting drug substances into the hair follicle. After penetration into the hair follicle, the nanocrystals could form a depot from which the active is released into the hair follicle. Thus, leading to a long-lasting and very efficient dermal drug delivery. The efficacy of nanocrystals to penetrate the hair follicles and the influence of the vehicle in which the nanocrystals are suspended was not yet investigated. Therefore, in this study curcumin nanocrystals with a size of about 300 nm were produced and incorporated into gels with different properties. The efficacy to penetrate the hair follicles, as well as the passive, dermal penetration, was assessed on the ex-vivo pig ear model. Nanocrystals were efficiently taken up by the hair follicles and reached the lower part of the infundibulum. This region is optimal for efficient drug delivery because the barrier of the lower infundibulum is not fully developed and thus more permeable, which results in a less hindered passive diffusion of drug substances. The penetration efficacy of the nanocrystals into the hair follicles was not affected by the different types of vehicles, which represented either oleogels or hydrogels that varied in viscosity as well as in the type and the concentration of the gelling agent. All gels possessed a shear-thinning flow behavior and it is hypothesized that all gels fluidized during the skin massage, whereby leading to similarly low viscosities than the aqueous nanosuspension and thus to similar penetration results. The passive, dermal penetration of curcumin was different for the different gels and the main driving parameter leading to good passive diffusion was caused by good skin hydrating properties of the vehicle. The best passive penetration was achieved from hydrogels that contained a humectant. However, the addition of the humectant reduced the efficacy of the nanocrystals to penetrate the hair follicle. Data so far, therefore, suggest that hair follicle targeting with nanocrystals that are suspended in water or simple, shear-thinning gels is highly effective. However, the addition of other excipients, e.g. humectants, to these vehicles might cause changes in the penetration profiles. More research in this regard is needed to understand these observations in more detail.

PlantCrystals-Nanosized Plant Material for Improved Bioefficacy of Medical Plants

PlantCrystals are obtained by milling plant material to sizes < 10 µm. Due to the disruption of the plant cells, active compounds are easily released, rendering the PlantCrystal technology an effective and low-cost process for the production of environmentally friendly plant extracts. The extracts can be used to produce phytomedicines, nutritional supplements or cosmetic products. Previous studies could already demonstrate the use of PlantCrystals to improve the antimicrobial or antifungal activity of different plants. This study investigated whether PlantCrystal technology is suitable to produce plant derived formulations with high antioxidant capacity. The study also aimed to identify the most suitable production methods for this. Methods: Various plant materials and parts of plants, i.e., seeds, leaves and flowers, and different methods were employed for the production. PlantCrystals were characterized regarding size, physical stability and antioxidant capacity (AOC). Results: PlantCrystals with particles < 1 µm were produced from the different plant materials. Both production methods, i.e., high-pressure homogenization, bead milling or the combination of both were suitable to obtain PlantCrystals. Nano milling of the plant material greatly affected their AOC and resulted in formulations with distinctly higher AOC when compared to classical extracts. Conclusions: Rendering plant material into small sized particles is highly effective to obtain plant extracts with high biological efficacy.

Optimization of Curcumin Nanocrystals as Promising Strategy for Nose-to-Brain Delivery Application

Intranasal (IN) drug delivery is recognized to be an innovative strategy to deliver drugs to the Central Nervous System. One of the main limitations of IN dosing is the low volume of drug that can be administered. Accordingly, two requirements are necessary: the drug should be active at a low dosage, and the drug solubility in water must be high enough to accommodate the required dose. Drug nanocrystals may overcome these limitations; thus, curcumin was selected as a model drug to prepare nanocrystals for potential IN administration. With this aim, we designed curcumin nanocrystals (NCs) by using Box Behnken design. A total of 51 formulations were prepared by the sonoprecipitation method. Once we assessed the influence of the independent variables on nanocrystals' mean diameter, the formulation was optimized based on the desirability function. The optimized formulation was characterized from a physico-chemical point of view to evaluate the mean size, zeta potential, polidispersity index, pH, osmolarity, morphology, thermotropic behavior and the degree of crystallinity. Finally, the cellular uptake of curcumin and curcumin NCs was evaluated on Olfactory Ensheathing Cells (OECs). Our results showed that the OECs efficiently took up the NCs compared to the free curcumin, showing that NCs can ameliorate drug permeability.

Nano Encapsulated Curcumin: And Its Potential for Biomedical Applications

Curcumin, a yellow-colored polyphenol extracted from the rhizome of turmeric root, is commonly used as a spice and nutritional supplement. It exhibits many pharmacological activities such as anti-inflammatory, anti-bacterial, anti-cancer, anti-Alzheimer, and anti-fungal. However, the therapeutic application of curcumin is limited by its extremely low solubility in aqueous buffer, instability in body fluids, and rapid metabolism. Nano delivery system has shown excellent potential to improve the solubility, biocompatibility and therapeutic effect of curcumin. In this review, we focus on the recent development of nano encapsulated curcumin and its potential for biomedical applications.

Can machine learning predict drug nanocrystals?

Nanocrystals have exhibited great advantage for enhancing the dissolution rate of water insoluble drugs due to the reduced size to nanoscale. However, current pharmaceutical approaches for nanocrystals formulation development highly depend on the expert experience and trial-and-error attempts which remain time and resource consuming. In this research, we utilized machine learning techniques to predict the particle size and polydispersity index (PDI) of nanocrystals. Firstly, 910 nanocrystal size data and 341 PDI data by three preparation methods (ball wet milling (BWM) method, high-pressure homogenization (HPH) method and antisolvent precipitation (ASP) method) were collected for the construction of the prediction models. The results demonstrated that light gradient boosting machine (LightGBM) exhibited well performance for the nanocrystals size and PDI prediction with BWM and HPH methods, but relatively poor predictions for ASP method. The possible reasons for the poor prediction refer to low quality of data because of the poor reproducibility and instability of nanocrystals by ASP method, which also confirm that current commercialized products were mainly manufactured by BWM and HPH approaches. Notably, the contribution of the influence factors was ranked by the LightGBM, which demonstrated that milling time, cycle index and concentration of stabilizer are crucial factors for nanocrystals prepared by BWM, HPH and ASP, respectively. Furthermore, the model generalizations and prediction accuracies of LightGBM were confirmed experimentally by the newly prepared nanocrystals. In conclusion, the machine learning techniques can be successfully utilized for the predictions of nanocrystals prepared by BWM and HPH methods. Our research also reveals a new way for nanotechnology manufacture.

A Comparative Study of the Effect of Different Stabilizers on the Critical Quality Attributes of Self-Assembling Nano Co-Crystals

Lamivudine (3TC) and zidovudine (AZT) are antiviral agents used orally to manage HIV/AIDS infection. A pseudo one-solvent bottom-up approach was used to develop and produce nano co-crystals of 3TC and AZT. Equimolar amounts of 3TC dissolved in de-ionized water and AZT in methanol were rapidly injected into a pre-cooled vessel and sonicated at 4 °C. The resultant suspensions were characterized using a Zetasizer. The particle size, polydispersity index and Zeta potential were elucidated. Further characterization was undertaken using powder X-ray diffraction, Raman spectroscopy, Fourier transform infrared spectroscopy, differential scanning calorimetry, and energy dispersive X-ray spectroscopy scanning electron microscopy. Different surfactants were assessed for their ability to stabilize the nano co-crystals and for their ability to produce nano co-crystals with specific and desirable critical quality attributes (CQA) including particle size (PS) < 1000 nm, polydispersity index (PDI) < 0.500 and Zeta potential (ZP) < -30 mV. All surfactants produced co-crystals in the nanometer range. The PDI and PS are concentration-dependent for all nano co-crystals manufactured while only ZP was within specification when sodium dodecyl sulfate was used in the process.

Eudragit S100 Entrapped Liposome for Curcumin Delivery: Anti-Oxidative Effect in Caco-2 Cells

Curcumin is a natural polyphenol with strong antioxidant activity. However, this molecule shows a very poor bioavailability, instability, and rapid metabolism in vivo. In this work curcumin was loaded in Eudragit-coated liposomes to create a gastroresistant carrier, able to protect its load from degradation and free it at the site of absorption in the colon region. Small unilamellar vesicles were prepared and coated with Eudragit by a pH-driven method. The physico-chemical properties of the prepared systems were assessed by light scattering, transmission electron microscopy, infrared spectroscopy, and differential scanning calorimetry. The uptake of vesicles by Caco-2 cells and the anti-oxidant activity in cells were evaluated. The produced vesicles showed dimensions of about forty nanometers that after covering with Eudragit resulted to have micrometric dimensions at acid pH. The experiments showed that at pH > 7.0 the polymeric coating dissolves, releasing the nanometric liposomes and allowing them to enter Caco-2 cells. Delivered curcumin loaded vesicles were then able to decrease significantly ROS levels as induced by H2O2 in Caco-2 cells. The proposed work showed the possibility of realizing effective gastroresistant curcumin liposome formulations for the delivery of antioxidant molecules to Caco-2 cells, potentially applicable to the treatment of pathological conditions related to intestinal oxidative stress.

Nanocarriers: A Successful Tool to Increase Solubility, Stability and Optimise Bioefficacy of Natural Constituents

Natural products are fascinating molecules in drug discovery for their exciting structure variability and also for their interaction with various targets. Drugs multi-targeting effect represents a more realistic approach to develop successful medications for many diseases. However, besides a large number of successful in vitro and in vivo studies, most of the clinical trials fail. This is generally related to the scarce water solubility, low lipophilicity and inappropriate molecular size of natural compounds, which undergo structural instability in biological milieu, rapid clearance and high metabolic rate. Additionally, some molecules are destroyed in gastric juice or suffer to a massive pre-systemic metabolism in the liver, when administered orally, limiting their clinical use. A reduced bioavailability can also be linked to drug distribution/accumulation in non-targeted tissues and organs that increase the side effects lowering the therapeutic efficacy and patient compliance. Nanomedicine represents a favourable tool to increase bioavailability and activities of natural products. Generally, nanovectors provide a large surface area and can overcome anatomic barriers. Each nanovector has its own advantages, disadvantages, and characteristics. In this review, different nanocarriers made of compounds which are Generally Recognized As Safe (GRAS) for the delivery of natural products, marketed as food supplements and medicines are reported.

Surface stabilized atorvastatin nanocrystals with improved bioavailability, safety and antihyperlipidemic potential

Atorvastatin, a favored option for hyperlipidemia exhibits the problem of poor gastric solubility and low absolute bioavailability (12%) along with higher pre-systemic clearance (>80%). Therefore, to circumvent these limitations, atorvastatin nanocrystals were prepared using poloxamer-188 as stabilizer via high pressure homogenization technique followed by lyophilization. Various variables like drug to poloxamer-188 ratio, homogenization cycle, homogenization pressure, type and concentration of cryoprotectant were optimized to achieve uniform nanosized crystals with good dispersibility. Solid state characterization by ATR-FTIR and DSC revealed no incompatible physicochemical interaction between drug and excipients in formulation while DSC and PXRD collectively corroborated the reduced crystallinity of drug in nanocrystals. Size analysis and SEM confirmed nanometric size range of nanocrystals (225.43 ± 24.36 nm). Substantial improvement in gastric solubility (~40 folds) and dissolution rate of drug in nanocrystals was observed. Pharmacokinetic study in wistar rats revealed significant improvement in oral bioavailability (~2.66 folds) with atorvastatin nanocrystals compared to pure drug. Furthermore, reduction in serum total lipid cholesterol, LDL and triglyceride content justified the effectiveness of formulation at 50% less dose of atorvastatin along with improved plasma safety profile in comparison of pure drug. In conclusion, atorvastatin nanocrystals are safe and efficacious drug delivery system confirming potent competence in treatment of hyperlipidemic conditions with ease of scalability for commercialization.

Benefits of curcumin in brain disorders

Curcumin is widely consumed in Asia either as turmeric directly or as one of the culinary ingredients in food recipes. The benefits of curcumin in different organ systems have been reported extensively in several neurological diseases and cancer. Curcumin has got its global recognition because of its strong antioxidant, anti-inflammatory, anti-cancer, and antimicrobial activities. Additionally, it is used in diabetes and arthritis as well as in hepatic, renal, and cardiovascular diseases. Recently, there is growing attention on usage of curcumin to prevent or delay the onset of neurodegenerative diseases. This review summarizes available data from several recent studies on curcumin in various neurological diseases such as Alzheimer's disease, Parkinson's disease, Multiple Sclerosis, Huntington's disease, Prions disease, stroke, Down's syndrome, autism, Amyotrophic lateral sclerosis, anxiety, depression, and aging. Recent advancements toward increasing the therapeutic efficacy of curcuma/curcumin formulation and the novel delivery strategies employed to overcome its minimal bioavailability and toxicity studies have also been discussed. This review also summarizes the ongoing clinical trials on curcumin for different neurodegenerative diseases and patent details of curcuma/curcumin in India.

The effect of surface treatment on the brain delivery of curcumin nanosuspension: in vitro and in vivo studies

Background: Curcumin, a bioactive component with multiple characteristics, has been shown to have many therapeutic effects. However, there are several limitations regarding the use of curcumin such as instability, low solubility, poor bioavailability, and rapid elimination. Different approaches have been used to solve these problems.

Materials and methods: In this study, surface-modified nanosuspension (NS) is investigated as a novel brain delivery system. Two different methods were used for the preparation of nanosuspensions with two different stabilizers. The surface of the nanosuspensions was coated with D-α-tocopheryl polyethylene glycol 1,000 succinate (TPGS) and Tween 80 using physical adsorption. Curcumin NSs were prepared using two different top-down techniques by high-pressure homogenizer and probe sonicator. A validated sensitive and selective high-performance liquid chromatography method using fluorescence detection was used for the determination and quantification of curcumin. Pharmacokinetics and biodistribution of curcumin NSs and solutions after intravenous administration in rats were studied.

Results: Higher levels of curcumin in the brain were detected when Tween 80-coated NS was used compared with the curcumin solution and TPGS coated NS (TPGS-NS) (P-value<0.05). Absorption of ApoE and/or B by Tween 80-coated nanoparticles (NPs) from the blood were caused transferring of these NPs into the brain using receptor-mediated endocytosis. Distribution of TPGS-NS in the brain compared with the curcumin solution was higher (P-value<0.05). Higher levels of curcumin concentration in the liver, spleen, and lung were also observed with TPGS-NS.

Conclusion: The results of this study indicate that the surface-coating of NSs by Tween 80 may be used to improve the biodistribution of curcumin in the brain.

Anti-infective Properties of the Golden Spice Curcumin

The search for novel anti-infectives is one of the most important challenges in natural product research, as diseases caused by bacteria, viruses, and fungi are influencing the human society all over the world. Natural compounds are a continuing source of novel anti-infectives. Accordingly, curcumin, has been used for centuries in Asian traditional medicine to treat various disorders. Numerous studies have shown that curcumin possesses a wide spectrum of biological and pharmacological properties, acting, for example, as anti-inflammatory, anti-angiogenic and anti-neoplastic, while no toxicity is associated with the compound. Recently, curcumin’s antiviral and antibacterial activity was investigated, and it was shown to act against various important human pathogens like the influenza virus, hepatitis C virus, HIV and strains of Staphylococcus, Streptococcus, and Pseudomonas. Despite the potency, curcumin has not yet been approved as a therapeutic antiviral agent. This review summarizes the current knowledge and future perspectives of the antiviral, antibacterial, and antifungal effects of curcumin.