Curcumin Solid Dispersion Research Articles

The Preparation of Curcumin Sustained-Release Solid Dispersion by Hot Melt Extrusion—Ⅰ. Optimization of the Formulation

The purpose of this study was to optimize the formulation for developing curcumin sustained-release solid dispersion to increase the solubility of curcumin, delay drug release by hot-melt extrusion, and to explore the possibility of hot-melt extrusion for one-step preparation of insoluble drug sustained-release solid dispersion. The miscibility of curcumin and Eudragit RSPO and Eudragit RLPO were assessed by solubility parameter and melting point depression. Orthogonal test was used to optimize the formulation, based on the results of single-factor experiment, and the final optimal formulation: the ratio of the sustained-release carrier material RS/RL was 1:3, the ratio of drug and carrier was 1:6, and the porogen was used in an amount of 40% of the sustained-release carrier material. The curcumin solid dispersion of the best formulation had been prepared and had a significant sustained-release effect compared to the curcumin and the physical mixture.

Skimmed milk powder and pectin decorated solid lipid nanoparticle containing soluble curcumin used for the treatment of colorectal cancer

AbstractThis research is aimed at the preparation of biopolymeric skimmed milk powder (SMP) and pectin coated dual layer solid lipid nanoparticles loaded with soluble curcumin (CMN) to enhance the cytotoxicity of the drug delivered to the colon for colorectal cancer (CRC). The curcumin (C‐) and curcumin solid dispersion (C‐SD) (soluble curcumin) loaded solid lipid nanoparticle (SLN) (C‐SD‐SLN) are prepared by hot homogenization method and characterized its physicochemical properties. The surface of the C‐SD‐SLNs was coated with natural biopolymers of pectin and skimmed milk powder (SMP), called cetyl palmitate (CP)‐SD‐SLN. The resultant nanoparticles showed significantly high drug loading, better stability, and slower release profile (92.1%) in various GI conditions up to 72 H. zebra fish toxicity studies of CP‐SD‐SLN confirm its in vivo safety, and the result from in vitro cytotoxicity showed that 50% inhibition (26 μM/ml) is achieved with an amount of CP‐SD‐SLN, which was considerably lesser than free CMN. The result from flow cytometry analysis confirmed the cell cycle arrest in the G2/M phase (49.11%), and western blot analysis was performed to understand its molecular level apoptosis in Caco‐2 cells. The profound efficiency of SMP and pectin coated CP‐SD‐SLN is a promising preparation that indicated its potential application for CRC treatment without toxicity.Practical applicationThe pharma and biotech industry is seeking techniques to increase potential and reduce the toxicity of chemotherapeutic agents. The solid lipid nanoparticle (SLN) has fascinated significant attention in anticancer drug delivery generally because of the targeted delivery to the particular site and devoid of other tissues. The present investigation provides the efficiency of skimmed milk powder (SMP)‐coated lipid shell contains soluble curcumin to release the drug at colon and improve the metabolism and therefore increase the potential activity several fold than native curcumin. The results show that SMP and pectin coated SLN is a potential carrier for delivery to the colon and thus improve anticancer potential of human adenocarcinoma (Caco‐2) cells of curcumin. These results will contribute in designing SLN techniques for optimizing the wide‐ranging quality of natural curcumin.

Zn(II)-curcumin solid dispersion impairs hepatocellular carcinoma growth and enhances chemotherapy by modulating gut microbiota-mediated zinc homeostasis

Zinc(II) complexes of curcumin display moderate cytotoxicity towards cancer cells at low micromolar concentrations. However, the clinical use of zinc(II) complexes is hampered by hydrolytic insolubility and poor bioavailability and their anticancer mechanisms remain unclear. Here, we investigated the efficacy and mechanism of action of a polyvinylpyrrolidone (PVP-k30)-based solid dispersion of Zn(II)-curcumin (ZnCM-SD) against hepatocellular carcinoma (HCC) in vitro and in vivo. In vitro assays revealed ZnCM-SD not only reduced the viability of HepG2 cells and SK-HEP1 cells in a dose-dependent manner, but also potently and synergistically enhanced cell growth inhibition and cell death in response to doxorubicin by regulating cellular zinc homeostasis. ZnCM-SD was internalized into the cells via non-specific endocytosis and degraded to release curcumin and Zn2+ ions within cells. The anticancer effects also occur in vivo in animals following the oral administration of ZnCM-SD, without significantly affecting the weight of the animals. Interestingly, ZnCM-SD did not reduce tumor growth or affect zinc homeostasis in HepG2-bearing mice after gut microbiome depletion. Moreover, administration of ZnCM-SD alone or in combination with doxorubicin significantly attenuated gut dysbiosis and zinc dyshomeostasis in a rat HCC model. Notably, fecal microbiota transplantation revealed the ability of ZnCM-SD to regulate zinc homeostasis and act as a chemosensitizer for doxorubicin were dependent on the gut microbiota. The crucial role of the gut microbiota in the chemosensitizing ability of ZnCM-SD was confirmed by broad-spectrum antibiotic treatment. Collectively, ZnCM-SD could represent a simple, well-tolerated, safe, effective therapy and function as a novel chemosensitizing agent for cancer.

Ideal 1:1 stoichiometry curcumin inclusion complex induced potential apoptosisin colorectal adenocarcinoma cells: The clear image of necrosis and functionalized dying effect

Background: This study investigates the inclusion complex of curcumin (CMN) enhance the solubility, which can be utilized for the treatment of colorectal cancer (CRC) greater to free CMN. Methods: CMN solid dispersion (SD) prepared by a hot melt method using CMN with several carriers of poloxamers (P-407 and P-188), gelucire 50/13 (GLR) and mannitol (MNT). Prior, molecular modelling and phase solubility studieswere performed with drug and carriers. The SD characterized by in vitrodrug release, SEM and functionalize dyeing test. Additionally, the cytotoxicity and image of apoptosisresolved to utilize the colorectal adenocarcinoma cell lines. Results: The result showed that CMN-P-407 inclusion complex produced significant properties towards solubility (318 ± 14.46 fold) and dissolution (91 ± 0.431% at 30 min). Similarly, these data fit with insilico model. The IC50 value for inclusion complex found to be 74 and 52 µM/mL, while that for free CMN ranged from 146 and 116 µM/mL on the SW480 and Caco-2 cells respectively. Apoptosis study described that the cells are undergoing cell death by apoptosis and the small number of necrosis. Conclusion: The profound efficiency of CMN-P-407 SD indicated its potential application for CRC treatment by showing a higher capability of inhibiting cell growth compared to that of free CMN.

Evaluation of the Dietary Supplementation of a Formulation Containing Ascorbic Acid and a Solid Dispersion of Curcumin with Boric Acid against Salmonella Enteritidis and Necrotic Enteritis in Broiler Chickens.

Simple SummaryProphylactic or therapeutic administration of a 0.1% mixture containing ascorbic acid (AA) and a solid dispersion of curcumin (CUR) with polyvinylpyrrolidone (PVP) and boric acid (BA) (AA-CUR/PVP-BA) significantly reduced the concentration of Salmonella Enteritidis in broiler chickens and had a positive effect in slightly diminishing the negative impact of necrotic enteritis (NE).Two experiments were conducted to evaluate the effect of the prophylactic or therapeutic administration of a 0.1% mixture containing ascorbic acid and a solid dispersion of curcumin with polyvinylpyrrolidone and boric acid (AA-CUR/PVP-BA) against Salmonella Enteritidis (S. Enteritidis) in broiler chickens. A third experiment was conducted to evaluate the impact of the dietary administration of 0.1% AA-CUR/PVP-BA in a necrotic enteritis (NE) model in broiler chickens. The prophylactic administration of 0.1% AA-CUR/PVP-BA significantly decreased S. Enteritidis colonization in cecal tonsils (CT) when compared to the positive control group (PC, p < 0.05). The therapeutic administration of 0.1% AA-CUR/PVP-BA significantly reduced the concentration of S. Enteritidis by 2.05 and 2.71 log in crop and CT, respectively, when compared with the PC on day 10 post-S. Enteritidis challenge. Furthermore, the serum FITC-d concentration and total intestinal IgA levels were also significantly lower in chickens that received 0.1% AA-CUR/PVP-BA. Contrary, the PC group showed significantly higher total intestinal IgA levels compared to the negative control or AA-CUR/PVP-BA groups in the NE model. However, 0.1% AA-CUR/PVP-BA showed a better effect in reducing the concentration of S. Enteritidis when compared to the NE model. Further studies with higher concentration of AA-CUR/PVP-BA into the feed to extend these preliminary results are currently being evaluated.

Application of β ‐CD/HA composite as a potential SD carrier to improve the dissolution of curcumin

Curcumin is a natural active constituent with a great variety of beneficial biological and pharmacological activities, is a practically water-insoluble component. The scope of the present work was to prepare a solid dispersion (SD) formulation to enhance the dissolution rate of curcumin. The SD was prepared using curcumin and β-cyclodextrin (CD)/HA via a classical ethanol-based solvent evaporation method. The as-prepared β-CD/HA and SDs were selectively characterised by various analytical techniques including X-ray diffraction, transmission electron microscopy, scanning electron microscopy, specific surface area/pore size analysis, Fourier transform infrared spectroscopy, and high-performance liquid chromatography. According to the dissolution tests, it was confirmed that β-CD/HA–curcumin SD can significantly enhance the dissolution of curcumin. In addition, an increasing trend was seen between the β-CD weight ratio and the dissolution rate of curcumin, and β-CD/HA–curcumin (9:1) SD was shown to be the best formulation among all tested samples with over 90% curcumin dissolved in 180 min. Besides, β-CD/HA–curcumin (9:1) SD exhibited pH and medium-dependent curcumin release behaviours. The antioxidant activity of released curcumin showed no difference to original curcumin. These results clearly demonstrated β-CD/HA can be a promising SD carrier to improve the dissolution of curcumin.

Anchorage of curcumin onto PVP enhances anti-tumor effect of curcumin

Curcumin, a natural polyphenol compound, exhibits wide range of pharmacological activities. However, its poor aqueous solubility, weak stability, and rapid metabolism limit its potential development. In this study, solid dispersion of curcumin with PVP was developed. This study aimed to evaluate the loading capacity, stability, solubility, and anti-tumor activity of PVP-Cur solid dispersion. Scanning electron microscope (SEM), differential scanning calorimetry (DSC), X-ray powder diffraction (XRPD), and fourier transform infrared (FTIR) spectroscopy were used to investigate physical characterization of PVP-Cur. Loading capacity, stability, and solubility of PVP-Cur were evaluated by spectrophotometer. The biological effects of PVP-Cur on tumor cell proliferation and apoptosis were analyzed using CCK-8 assay and 7-AAD/AnnexinV-APC assay, respectively. PVP-cur-induced activation of caspase-3 and caspase-9 were evaluated by in vitro caspase activity assay and western blotting. It was interesting to note that PVP: curcumin in the ratios of 6:1 or 8:1 exhibited the highest loading capacity. Anchorage of curcumin onto PVP increased its solubility and stability. Compared with curcumin alone, PVP-Cur displayed an increased ability in abrogating tumor cell proliferation and inducing tumor cell apoptosis via mitochondria signaling, which was attributed by the enhanced cellular uptake of PVP-Cur. Anchorage of curcumin onto PVP was an effective way to increase the solubility and stability of curcumin. PVP-Cur increased anti-tumor ability and cellular uptake relative to curcumin, indicating that PVP-Cur is a promising candidate for anti-cancer drug development.

Preparation, physicochemical and pharmacological study of curcumin solid dispersion with an arabinogalactan complexation agent.

Pharmaceutical solid dispersions (SD) of curcumin (Cur) with macromolecule polysaccharide arabinogalactan (AG) from wood of Larix sibirica were prepared by mechanical ball milling. The physical properties of the dispersed curcumin mixture in solid state were characterized by scanning electron microscope, differential scanning calorimetry and powder X-ray diffraction studies. These methods showed a strong decrease in the degree of crystallinity of Cur and its transformation to amorphization state, accompanied by the formation of the guest-host type complexes. The behavior of the samples in solutions was characterized by reverse phase HPLC, 1H NMR spectroscopy, UV-Visible spectroscopy and gel permeation chromatography (GPC). Mechanochemically prepared complexes demonstrated the increased solubility of Cur up to ~10.5 times in contrast to pure curcumin. The rapid storage test showed high chemical stability of Cur, which depended on mass relations of Cur-AG. Besides, improved membrane permeability of Cur-AG SD was tested by parallel artificial membrane permeability assay. Pharmacokinetic study of Cur-AG SD formulation in rat demonstrated a significant~8-fold enhancement of bioavailability in comparison to pure curcumin. In MTT tests, Cur-AG SD showed moderate cytotoxicity against human glioblastoma cells and immortalized human fibroblasts. Therefore, Cur-AG solid dispersion was a more promising and efficacious formulation for application in oral drug delivery.

Zn(ii)-Curcumin supplementation alleviates gut dysbiosis and zinc dyshomeostasis during doxorubicin-induced cardiotoxicity in rats.

Doxorubicin is a powerful anticancer agent used to treat a variety of human neoplasms. However, the clinical use of doxorubicin is hampered by cardiotoxicity and effective cardioprotective adjuvants do not exist. Dietary zinc, an essential nutrient, is required to maintain steady-state tissue zinc levels and intestinal homeostasis and may yield therapeutic benefits in diseases associated with zinc dysregulation or gut dysbiosis. Here, we investigated the effects of dietary Zn(ii)-curcumin (ZnCM) solid dispersions on gut dysbiosis and zinc dyshomeostasis during doxorubicin-induced cardiotoxicity in rats. Rats were injected with multiple low doses of doxorubicin and orally administered ZnCM daily over four weeks. Daily administration of ZnCM not only alleviated Dox-induced gut dysbiosis-as indicated by the increased Firmicutes-to-Bacteroidetes ratio and the maintenance of the relative abundances of major beneficial bacteria including Clostridium_XIVa, Clostridium_IV, Roseburia, Butyricicoccus and Akkermansia-but also maintained intestinal barrier integrity and decreased the lipopolysaccharide (LPS) contents of feces and plasma. ZnCM also significantly attenuated doxorubicin-induced zinc dyshomeostasis, which was mirrored by preservation of zinc levels and expression of zinc-related transporters. Furthermore, ZnCM significantly improved heart function and reduced cardiomyocyte apoptosis and myocardial injury in doxorubicin-treated rats. Notably, the regulation of zinc homeostasis and cardioprotective and microbiota-modulating effects of ZnCM were transmissible through horizontal feces transfer from ZnCM-treated rats to normal rats. Thus, ZnCM supplementation has potential as an effective therapeutic strategy to alleviate gut dysbiosis and zinc dyshomeostasis during doxorubicin-induced cardiotoxicity.

In vitro and in vivo evaluation of enzymatic and antioxidant activity, cytotoxicity and genotoxicity of curcumin-loaded solid dispersions

Curcumin, the main bioactive polyphenolic compound in Curcuma longa L. rhizomes has a wide range of bioactive properties. Curcumin presents low solubility in water and thus limited bioavailability, which decreases its applicability. In this study, cytotoxic effects of curcumin solid dispersions (CurSD) were evaluated against tumor (breast adenocarcinoma and lung, cervical and hepatocellular carcinoma) and non-tumor (PLP2) cells, while cytotoxic and genotoxic effects were evaluated in Allium cepa. The effect of the CurSD on the acetylcholinesterase (AChE), butyrylcholinesterase (BChE), glutathione S-transferase (GST), and monoamine oxidase (MAO A-B) enzymes was determined, as well as its capacity to inhibit the oxidative hemolysis (OxHLIA) and the formation of thiobarbituric acid reactive substances (TBARS). CurSD are constituted by nanoparticles that are readily dispersible in water, and inhibited 24% and 64% of the AChE and BChE activity at 100 μM, respectively. GST activity was inhibited at 30 μM while MAO-A and B activity were inhibited at 100 μM. CurSD showed cytotoxicity against all the tested tumor cell lines without toxic effects for non-tumor cells. No cytotoxic and genotoxic potential was detected with the Allium cepa test. CurSD maintained the characteristics of free curcumin on the in vitro modulation of important enzymes without appreciable toxicity.

Evaluation of a Solid Dispersion of Curcumin With Polyvinylpyrrolidone and Boric Acid Against Salmonella Enteritidis Infection and Intestinal Permeability in Broiler Chickens: A Pilot Study

In the present study, in vitro assays were conducted to evaluate the solubility of curcumin (CUR) alone or with polyvinylpyrrolidone (PVP) at different pH, as well as its permeability in Caco-2 cells. Results confirmed that the solid dispersion of CUR with PVP (CUR/PVP) at a 1:9 ratio, significantly increased (P < 0.05) solubility and permeability compared to CUR alone. Then, the antimicrobial activity of CUR/PVP, boric acid (BA), and a combination of 0.5% CUR/PVP and 0.5% BA (CUR/PVP-BA) against Salmonella Enteritidis (SE) was determined using an in vitro digestion model that simulates crop, proventriculus, and intestine. The results revealed that in the proventriculus and intestinal compartments significant reductions of SE were observed in all the experimental treatments, but 1% BA eliminated SE in the intestinal compartment and CUR/PVP-BA showed a synergistic effect on antimicrobial activity against SE. To complement these findings, two independent in vivo trials were conducted to determine the effect of 0.1% CUR/PVP; 0.1% BA; or the combination of 0.05% CUR/PVP (1:9 ratio) and 0.05% BA (CUR/PVP-BA) on the antimicrobial activity against SE, intestinal permeability and inflammatory responses in broiler chickens. BA at 0.1% had no significant in vivo effects against SE. However, the combination of 0.05% BA and 0.05% CUR/PVP and 0.05% BA was sufficient to reduce crop and intestinal SE colonization in broiler chickens in two independent trials, confirming the synergic effect between them. A similar antimicrobial impact against SE intestinal colonization was observed in chickens treated with 0.1% CUR/PVP at a 1:9 ratio, which could be due to the increase in solubility of CUR by PVP. Furthermore, 0.1% CUR/PVP reduced the intestinal permeability of FITC-d and total intestinal IgA, as well as increase the activity of SOD when compared to control, while, CUR/PVP-BA only decreased SOD activity. Further studies to confirm and expand the in vivo results obtained in this pilot study, adding intestinal microbial commensal groups and more inflammatory biomarkers to get a complete description of the effects of BA and CUR deserves further investigation.

Association of Silver Nanoparticles and Curcumin Solid Dispersion: Antimicrobial and Antioxidant Properties.

The last century, more precisely after 1945, was marked by major advances in the treatment of infectious diseases which promoted a decrease in mortality and morbidity. Despite these advances, currently the development of antimicrobial resistance has been growing drastically and therefore there is a pressing need to search for new compounds. Silver nanoparticles (AgNps) have been demonstrating good antimicrobial activity against different bacteria, viruses, and fungi. Curcumin (CUR) extracted from rhizomes of Curcuma longa has a variety of applications including antiinflammatory, antioxidant, and antibacterial agent. The association between silver nanoparticles and curcumin in a formulation can be a good alternative to control infectious diseases due the antimicrobial properties of both compounds. The objective of this work was to develop a formulation composed of a thermoresponsive gel-with antimicrobial and antioxidant properties due to the association of AgNps with PVP and PVA polymers. After AgNp synthesis, these were incorporated together with the previously prepared CUR/P407 (1:2) solid dispersion (SD) into a polymer dispersion of 20% P407 (thermosensitive gel). Our results showed that the association between the AgNps with CUR SD demonstrated good antioxidant activity as compared to the standard compound. Measures of MIC showed more efficacy against Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa) than for Gram-positive bacteria (Staphylococcus aureus). This association enhances antimicrobial activity against E. coli and P aeruginosa and added antioxidant value in formulations.

Characterization, in Vivo and in Vitro Evaluation of Solid Dispersion of Curcumin Containing d-α-Tocopheryl Polyethylene Glycol 1000 Succinate and Mannitol.

The aim of this study was to prepare a solid dispersion formulation of curcumin to enhance its solubility, dissolution rate, and oral bioavailability. The formulation was prepared with d-α-tocopheryl polyethylene glycol 1000 succinate (TPGS) and mannitol using solvent evaporation and freeze-drying methods, which yielded a solid dispersion composed of curcumin, TPGS, and mannitol at a ratio of 1:10:15 (w/w/w). The solubility and dissolution rate of the curcumin solid dispersion markedly improved compared with those of curcumin powder and a physical mixture of curcumin, TPGS, and mannitol. About 90% of the curcumin was released from the solid dispersion formulation within 10 min. After administering the formulation orally to rats, higher plasma concentrations of curcumin were observed, with increases in the maximum plasma concentration (Cmax) and area under the plasma concentration-time curve (AUC) of 86- and 65-fold, respectively, compared with those of curcumin powder. The solid dispersion formulation effectively increased intestinal permeability and inhibited P-gp function. These effects increased the anti-proliferative effect of curcumin in MDA-MB-231 breast cancer cells. Moreover, 2 h incubation with curcumin powder, solid dispersion formulation, and its physical mixture resulted in differential cytotoxic effect of paclitaxel in P-gp overexpressed LLC-PK1-P-gp and MDA-MB-231 cells through the inhibition of P-gp-mediated paclitaxel efflux. In conclusion, compared with curcumin, a solid dispersion formulation of curcumin with TPGS and mannitol could be a promising option for enhancing the oral bioavailability and efficacy of curcumin through increased solubility, dissolution rate, cell permeability, and P-gp modulation.

DESIGN AND OPTIMIZATION OF ORAL BIOADHESIVE NANOCURCUMIN DELIVERY USING NOVEL HYDROPHILIC CARRIER FOR CANCER TREATMENT: AN ALTERNATIVE TO PARENTERAL CHEMOTHERAPY

Present study involves the design and optimization of oral bioadhesive delivery system of curcumin. Solid dispersion of curcumin was developed using novel hydrophilic carrier, Gelucire® 50/13, by melt granulation technique. Based on HPMC K 100 LV(X1) and carbopol 934P (X2), bio-adhesive tablets containing curcumin solid dispersion was developed by direct compression, using central composite designs for two factors at three levels. Tablet formulation was optimized for t50%, Rel24h and bioadhesive strength. The drug release mechanism was found to be by fickian diffusion, approaching zero-order kinetics. Average plasma uptake of curcumin was found to be 0.289μg/mL as compared to plain curcumin tablet formulation. The results were found highly significant (p&lt;0.05). The swelling matrices behavior over the time period studied showed that the gelling layer thickness increases continuously. From this study, it may be concluded that the oral controlled bioadhesive curcumin delivery may be an alternative to parenteral chemotherapy.

Solid Dispersion of Curcumin as Polymeric Films for Bioenhancement and Improved Therapy of Rheumatoid Arthritis.

The aim of our study was development of advanced third generation Curcumin self microemulsifying composition solid dispersion (Cur SMEC-SD) with high drug loading, improved stability, rapid in-vitro dissolution and enhanced bioavailability for improved therapy of rheumatoid arthritis. The Cur SMEC-SD comprising polymers (KollidonVA64[KVA], Eudragits, HPMC and Soluplus) and self microemulsifying composition of surfactant:co-surfactant:oil were coated onto rapidly disintegrating inert tablet core. SDs evaluated for stability, in-vitro release and bioenhancement. Cur SMEC-SDs exhibited high Cur loading of 45% w/w and microemulsion formation with globule size (~100nm) irrespective of polymers. Among the polymers, SD with KVA revealed exceptionally low contact angle (7°C) and rapid in-vitro release (t50%-6.45min). No crystallization was evident as confirmed by SEM, DSC and XRD and is attributed to SMEC aided solubilization/amorphisation, and interaction of KVA with Cur seen in the FTIR spectra. Stability was confirmed as per ICH guidelines. Remarkable bioenhancement with Cur SMEC-SD was confirmed by the > four fold and a two fold compared to Cur and Cur-SD without SMEC respectively. High efficacy ~ 80% compared to Indomethacin, seen with rheumatoid arthritis (RA) induced rats coupled with no adverse toxicity. The advanced third generation Cur SMEC-SD presents a practical technological advancement and suggests Cur SMEC-SD as promising alternative for RA therapy.

Enhanced solubility and dissolution of curcumin by a hydrophilic polymer solid dispersion and its insilico molecular modeling studies

Curcumin (CUR) is highly lipophilic drug that shows degradation at alkaline pH which restricts its oral bioavailability. The aim of the present study was to enhance the oral bioavailability of CUR by increasing its solubility and dissolution rate. Solid dispersions (SDs) of CUR in aqueous and organic solvent using Eudragit EPO (EuD) were prepared by spray drying and rota evaporation technique. The solubility of plain CUR in acidic pH 1.2 is only 0.02% whereas SDs containing EuD have solubilities of 40.29% and 18.78% by spray drying and rota evaporation technique respectively. Physical characterization by SEM, IR, DSC, and XRD studies, revealed the changes in solid state during the formation of dispersion and justified the decreased crystallinity of CUR SDs. Dissolution studies showed that pH values influenced the release profile lower the pH values higher the release speed (pH 1.2). CUR in pH 1.2 showed negligible release even after 120 min (2–5%) whereas, SDs showed 20–45% drug release after 60 min. Further, insilico docking study was carried out followed by molecular dynamic simulations to understand the molecular level binding interactions between drug and polymer. The insilico studies demonstrates the role of van der Waals interactions in binding of CUR to EuD.

Development and evaluation of gastroretentive raft forming systems incorporating curcumin-Eudragit® EPO solid dispersions for gastric ulcer treatment

Novel raft forming systems incorporating curcumin-Eudragit® EPO solid dispersions were developed to prolong the gastric residence time and provide for a controlled release therapy of curcumin to treat gastric ulcers. The solid dispersions of curcumin with Eudragit® EPO were prepared by the solvent evaporation method at various ratios to improve the solubility and the dissolution of curcumin. The optimum weight ratio of 1:5 for curcumin to Eudragit® EPO was used to incorporate into the raft forming systems. The raft forming formulations were composed of curcumin-Eudragit® EPO solid dispersions, sodium alginate as a gelling polymer and calcium carbonate for generating divalent Ca2+ ions and carbon dioxide to form a floating raft. All formulations formed a gelled raft in 1min and sustained buoyancy on the 0.1N hydrochloric acid (pH 1.2) surface with a 60–85% release of curcumin within 8h. The curative effect on the acetic acid-induced chronic gastric ulcer in rats was determined. The curcumin raft forming formulations at 40mg/kg once daily showed a superior curative effect on the gastric ulcer in terms of the ulcer index and healing index than the standard antisecretory agent: lansoprazole (1mg/kg, twice daily) and a curcumin suspension (40mg/kg, twice daily). These studies demonstrated that the new raft forming systems containing curcumin solid dispersions are promising carriers for a stomach-specific delivery of poorly soluble lipophilic compounds.

Microparticles Containing Curcumin Solid Dispersion: Stability, Bioavailability and Anti-Inflammatory Activity.

This work aimed at improving the solubility of curcumin by the preparation of spray-dried ternary solid dispersions containing Gelucire®50/13-Aerosil® and quantifying the resulting in vivo oral bioavailability and anti-inflammatory activity. The solid dispersion containing 40% of curcumin was characterised by calorimetry, infrared spectroscopy and X-ray powder diffraction. The solubility and dissolution rate of curcumin in aqueous HCl or phosphate buffer improved up to 3600- and 7.3-fold, respectively. Accelerated stability test demonstrated that the solid dispersion was stable for 9 months. The pharmacokinetic study showed a 5.5-fold increase in curcumin in rat blood plasma when compared to unprocessed curcumin. The solid dispersion also provided enhanced anti-inflammatory activity in rat paw oedema. Finally, the solid dispersion proposed here is a promising way to enhance curcumin bioavailability at an industrial pharmaceutical perspective, since its preparation applies the spray drying, which is an easy to scale up technique. The findings herein stimulate further in vivo evaluations and clinical tests as a cancer and Alzheimer chemoprevention agent.

Poloxamer-based curcumin solid dispersions for ex tempore preparation of supersaturated solutions intended for antimicrobial photodynamic therapy

Phototoxic effect of curcumin supersaturated solutions toward pathogenic bacteria has already been demonstrated. However, to be useful in the clinical practice, a supersaturated solution needs to be physically and chemically stabile over the relevant time period. Poloxamer-based solid dispersions (SD) intended for ex tempore preparation of a supersaturated solution were designed to simultaneously facilitate dissolution and inhibit precipitation of curcumin in vitro. Due to the transformation of the crystalline compound to an amorphous form, as shown by X-ray powder diffraction, the desired concentration of curcumin could easily be achieved upon hydration of SDs. The efficiency of selected poloxamers (Pluronic® F-127, F-68 and P-123) as the precipitation inhibitors (PIs) and influence of an additional PI (polyethylene glycol 400, hydroxypropyl methylcellulose, and hyaluronic acid) on the physical stability of the solutions were examined by UV–Vis spectrophotometry. HPLC-PDA was employed to evaluate hydrolytic and photolytic stability of curcumin in the SD solutions. At sub-micellar concentrations, Pluronics® F-127 and P-123, but not F-68, delayed curcumin precipitation in aqueous media and protected the compound from hydrolytic degradation up to 24 h. Complete inactivation of Enterococcus faecalis was achieved after exposure to solutions of selected SDs at curcumin concentration ≥1 µM and the light dose of 9.4 J/cm2.

Formulation and characterization of lyophilized curcumin solid dispersions for antimicrobial photodynamic therapy (aPDT): studies on curcumin and curcuminoids LII

Context: Bacterial resistance to antibiotics is increasing and alternative antibacterial treatments like antimicrobial photodynamic therapy (aPDT) are needed. Curcumin is under investigation as a potential photosensitizer in aPDT.Objective: The purpose of this study was to develop rapidly dissolving formulations of curcumin that could photoinactivate both Gram-positive and Gram-negative bacteria.Materials and methods: Curcumin solid dispersions with methyl-β-cyclodextrin and hyaluronic acid (HA), hydroxypropyl methylcellulose (HPMC) or both HA and HPMC were prepared through lyophilization. The lyophilizates were characterized by curcumin drug load [% (w/w)], differential scanning calorimetry, photostability, thermal stability, their ability to form supersaturated solutions and by in vitro photoinactivation of Enterococcus faecalis and Escherichia coli.Results and discussion: The lyophilizates were amorphous solid dispersions with a curcumin drug load in the range of 1.4–5.5% (w/w) depending on the included polymer and the ratio between curcumin and the cyclodextrin. The lyophilizates were photolabile, but thermally stable and dissolved rapidly in contact with water to form supersaturated solutions. Selected lyophilizates demonstrated >log 6 reduction of colony forming units/ml of both E. faecalis and E. coli after exposure to low curcumin concentrations (0.5–10 µM) and blue light dose (11–16 J/cm2). The high drug load of the lyophilizates, rapid dissolution, ability to form relatively stable supersaturated solutions and the very high phototoxicity towards both E. faecalis and E. coli make these lyophilizates suitable for in vivo aPDT.Conclusions: This treatment with optimized curcumin formulations should be explored as an alternative to topical antibiotics in the treatment of wound infections.