Title Science and Technology Indonesia e-ISSN:2580-4391 p-ISSN:2580-4405 Vol. 8, No. 3, July 2023 Research Paper Increasing the Solubility and Anti-Inflammatory Activity of Curcumin by Cocrystallization Yudi Wicaksono1*, Kuni Zu’aimah Barikah1, Amanda Della Yudatama1, Havidhatul Maulia1, Nuri2, Dwi Setyawan3 1API and Excipient Research Group, Faculty of Pharmacy, University of Jember, Jember, 68121, Indonesia2Bio-Active Natural Product Development Research Group, Faculty of Pharmacy, University of Jember, Jember, 68121, Indonesia3Faculty of Pharmacy, Airlangga University, Surabaya, 60286, Indonesia *Corresponding author: yudi.farmasi@unej.ac.id AbstractCurcumin (CUR) is a polyphenolic compound that exhibits potent anti-inflammatory activity. However, only a tiny amount of CUR isabsorbed during oral administration, which is because CUR is difficult to dissolve in water. The aim of the research was to increase thesolubility of CUR through the cocrystallization technique using isonicotinamide coformer (INIC) by solvent evaporation. Cocrystalcharacterization was carried out using a powder X-ray diffractometer (PXRD), a differential scanning calorimeter (DSC), a Fouriertransform infrared spectrometer (FTIR), and a scanning electron microscope (SEM). Solubility was evaluated using the shakingmethod, while the anti-inflammatory activity test was carried out using the carrageenan-induced mouse leg edema method. Theresulting CUR-INIC (1:1) cocrystal has a diffractogram with new diffraction peaks of 2\ at 15.00, 16.22, and 22.89◦ compared tothe individual diffractograms of CUR and INIC. In the cocrystal, CUR and INIC form intermolecular interactions of hydrogen bonds,resulting in a new solid phase with a melting point of 160.1◦C. The solubility of the CUR-INIC cocrystal in water was 73.1±0.23 `g/mL,which increased 14 times compared to the solubility of initial CUR, which was only 5.05±0.07 `g/mL. The CUR-INIC cocrystalshowed a percentage of edema inhibition in mice (5 hours) 130% more potent than that of initial CUR. Therefore, CUR-INIC cocrystalscan be used to improve CUR solubility to obtain more excellent anti-inflammatory effects. KeywordsCurcumin, Solubility, Anti-Inflammatory, Cocrystals, Isonicotinamide Received: 23 January 2023, Accepted: 1 July 2023 https://doi.org/10.26554/sti.2023.8.3.501-508 1. INTRODUCTION Curcumin (CUR) is a polyphenol compound with various bi- ological activities such as anti-inflammatory, antioxidant, and anti-tumor (Sohn et al., 2021) . CUR has been shown to have potent anti-inflammatory effects in various inflammatory dis- eases in clinical trials. The anti-inflammatory effect of CUR is considered to be the basis of various pharmacological activ- ities which play an essential role in the treatment of various diseases. Therefore, CUR is considered one of the natural com- pounds with tremendous potential in treating diseases (Peng et al., 2021) . However, until now, the use of CUR as a ther- apeutic drug is still constrained by pharmacokinetics (Sohn et al., 2021; Tabanelli et al., 2021; Hakim et al., 2021). CUR given orally is very little absorbed in the gastrointestinal tract, so its bioavailability to achieve pharmacological effects is less than 1% (Suresh and Nangia, 2018; Peng et al., 2021). One reason for the low absorption of CUR in the gastrointestinal tract is that CUR is very slightly soluble in water (<8 mg/L) (Suresh and Nangia, 2018; Zhang et al., 2023). The structure of the CUR molecule has two aromatic ring systems with o- methoxy phenolic groups, connected by seven carbon linkers consisting of an 𝛼, 𝛽 -unsaturated 𝛽 -diketone groups so that it is hydrophobic and difficult to dissolve in water (Priyadarsini, 2014; Suresh and Nangia, 2018). Various techniques have been used to increase the solubility of active pharmaceutical ingredients (API), one of which is the formation of multicomponent solids (Sohn et al., 2021; San- phui and Bolla, 2018; Fang et al., 2021). A multicomponent solid is formed from an API and a coformer, resulting in a new solid phase (Haneef and Chadha, 2017; Palanisamy et al., 2019). The API can be prepared into a multicomponent solid with certain coformer so the solubility can increase (Haneef and Chadha, 2017; Chavan and Shastri, 2018; Wicaksono et al., 2021; Anggraini et al., 2022). Cocrystallization is an exciting and attractive technique for forming multicomponent solids to increase the solubility of API (Karimi-Jafari et al., 2018) . Cocrystals are multicomponent https://crossmark.crossref.org/dialog/?doi=10.26554/sti.2023.8.3.501-508&domain=pdf https://doi.org/10.26554/sti.2023.8.3.501-508 Wicaksono et. al. Science and Technology Indonesia, 8 (2023) 501-508 solids formed by two or more types of molecules with non- covalent interactions such as hydrogen bonds, van der Waals interactions, and 𝜙-𝜙 interactions (Haneef and Chadha, 2017; Sanphui and Bolla, 2018; Wicaksono et al., 2020). Cocrys- tals can increase the solubility of crystalline API through the mechanism of decreasing crystal lattice energy so that API in crystalline solids is more easily hydrated by water molecules (Ozaki et al., 2014; Docherty et al., 2015; Bergström and Lars- son, 2018). The increased solubility of API by cocrystallization has thermodynamic advantages because its formation is usually spontaneous, the resulting solid is energetically more stable than its pure form, and the cocrystal structure is separate from the constituent components (Maheshwari et al., 2009; Fischer et al., 2016; Taylor and Day, 2018). Another critical advan- tage of cocrystallization is that the API and coformer interact through non-covalent interactions so that they do not change the molecular structure and pharmacological activity of the API (Haneef et al., 2021; Guo et al., 2021; Acebedo-Martínez et al., 2022). The aim of this research is to increase the solubility of CUR by cocrystallization technique so that CUR becomes more eas- ily absorbed in the gastrointestinal tract and has greater bioavail- ability to achieve therapeutic effects as an anti-inflammatory (Suresh and Nangia, 2018; Gao et al., 2019; Chen et al., 2020; Peng et al., 2021). The CUR molecule has a beta-diketol group and two phenolic groups, which are known to be highly reac- tive in forming intermolecular interactions of hydrogen bonds (Suresh and Nangia, 2018; Sanphui and Bolla, 2018; He et al., 2019). CUR and n-acetylcysteine coformer using the super- critical solvent method indicated the cocrystal formation with higher solubility than the initial CUR (Paulazzi et al., 2022) . CUR can also form cocrystals with ascorbic acid coformer by solvent evaporation, where the solubility can also increase sig- nificantly compared to the initial CUR (Pantwalawalkar et al., 2021) . CUR cocrystallization was carried out with isonicoti- namide (INIC) as a coformer by solvent evaporation. INIC was chosen as a coformer because structurally, it has amide groups and furan rings, so it has the potential to form short-strong hy- drogen bonds with hydroxyl groups on CUR molecules (Kerr et al., 2015) . In addition, INIC is easily soluble in water, so it is likely to increase the solubility of the resulting cocrystal (Suresh and Nangia, 2018) . 2. EXPERIMENTAL SECTION 2.1 Chemicals and Equipment The chemicals used were CUR (Tokyo Chemical Industry Co., Ltd.), INIC (Sigma-Aldrich®), CMC-Na (Merck®), car- rageenan (Sigma-Aldrich®), and methanol (PT. Smart Lab Indonesia). The experimental animals used were male BALB/c rats (20-30 g) obtained from the Faculty of Dentistry Univer- sity of Jember. The research equipment used was a powder X-ray diffractometer (PXRD), a differential scanning calorime- ter (DSC), a Fourier-transform infrared spectrometer (FTIR), a scanning electron microscope (SEM) equipped with an ion sputter, a UV-Vis spectrophotometer, a magnetic stirrer, and an orbit shaker. 2.2 Methods 2.2.1 Cocrystallization of CUR-INIC CUR and INIC in an equimolar ratio (1:1) were put into a beaker (total weight 1 g). 10 mL of methanol was added to the beaker glass, then tightly closed with aluminum foil. The mixture in the beaker glass was then stirred with a magnetic stirrer (Thermo Fisher SP88857107) at 300 rpm (30◦C) for 30 minutes, and after that, the aluminum foil covering the beaker glass was given small holes. The beaker was gently shaken with an orbital shaker (Thermo Scientific) at 125 rpm (30◦C) so that the solvent evaporated, leaving the solid. The dry solids were then reduced with a mortar and sieved through an 80-mesh sieve. 2.2.2 Characterization with PXRD Tests were carried out with a PANalytical X’Pert Pro diffrac- tometer using CuK𝛼1 (_ =1.542 Å) as a radiation source. Scan- ning at an angle of 2 𝛽 with a speed of 10◦/min uses a size range of 5-50◦ with a voltage of 40 kV and a current of 30 mA. 2.2.3 Characterization with DSC The equipment used was Thermo plus EVO DSC 8230. The sample (approximately 2 mg) was put into an airtight alu- minum pan and closed tightly with a press apparatus. The sam- ple is then placed on the sample board on the DSC. The DSC test was carried out under dry airflow conditions with a temper- ature range of 30-200◦C and a heating rate of 10◦C/minute. 2.2.4 Characterization with FTIR FTIR spectra were determined using a Fourier transform in- frared spectrometer (Thermo Scientific Nicolet iS10). A sam- ple of about 5 mg was sprinkled evenly on the board from the equipment, and then measurements were taken using a resolution of 4 cm−1 at a wave number of 4000-600 cm−1. 2.2.5 Characterization with SEM The equipment used is a Hitachi TM 3000 with an ion sputter (Hitachi E-1045). The sample powder was placed evenly on the sample board, then coated with platinum using an ion sputter for 20 seconds. Then the samples were observed using SEM at a voltage of 15 kV and a current of 30 mA with the appropriate magnification. 2.2.6 Solubility Test The solubility test using an excess sample (about 20 mg) was carried out by shaking method. Samples were containerized with Erlenmeyer, and added 10 mL of distilled water. Then the Erlenmeyer was tightly closed using aluminum foil and shaken for 24 hours using an orbital shaker (Thermo Scientific) at 175 rpm (30◦C). The supernatant was filtered (0.45 microns) and diluted with sufficient methanol, and then the CUR level was measured using a UV-Vis spectrophotometer at _ 425 nm (Thermo Scientific Genesys 20). The solubility test was repeated thrice (Hanif et al., 2022) . © 2023 The Authors. Page 502 of 508 Wicaksono et. al. Science and Technology Indonesia, 8 (2023) 501-508 2.2.7 Evaluation of Anti-Inflammatory Activity Anti-inflammatory activity was evaluated using the mice-car- rageenan-induced paw edema method (Gupta et al., 2015; Ahangar et al., 2019; Yimer et al., 2020). The experimental an- imal treatment procedure was approved by the Research Ethics Committee of the University of Jember (No. 1360/UN25.8/K EPK/DL/2021). Male BALB/c mice (20-30 g) were grouped into three (6 mice each): the control group (I), the pure CUR group (II), and the CUR-INIC group (III) (Ma et al., 2019; Zhnyakina et al., 2020). Mice were acclimatized for seven days by being given water and a standard diet ad libitum under standard conditions. Before being treated, the mice fasted for 12 hours (no diet but still given water). Treatment was given by gavage, 0.5% CMC-Na suspension (0.1 mL/kg BW) to group I (control group), 0.5% CMC Na suspension containing CUR (dose 200 mg/kg BW) to group II, and 0.5% CMC Na suspension containing CUR-INIC (dose equivalent to CUR of 200 mg/kg BW) to group III. After administration of the suspension, the thickness of the right hind paw of the mice was measured with a caliper (T0). One hour after administration of the suspension, the right hind paw of the mice (sub-plantar area) was injected with 0.01 mL of 1% carrageenan. Furthermore, after 0.5, 1, 2, 3, 4, and 5 hours of 1% carrageenan treatment, the thickness of the right hind paw of the mice has measured again (Tt). The changes in the thickness of the paw (Δ) were calculated as the difference between the paw thickness after injection (Tt) and the paw thickness before injection (T0). The percentage of edema inhibition (5 hours after injection of 1% carrageenan) was calculated by the formula: % edema inhibition = [(Δcontrol-Δtreatment)/Δcontrol] × 100 (Gupta et al., 2015) . 2.2.8 Statistical Analysis Statistical analysis was carried out using one-way ANOVA and Bonferroni post hoc test on the SPSS 22.0 software program. Differences in data between sample groups were considered significant if the p-value<0.05. 3. RESULTS AND DISCUSSION 3.1 PXRD Diffractogram The PXRD diffractograms of CUR, INIC, and CUR-INIC are shown in Figure 1. The PXRD diffractograms of CUR have shown sharp peaks at 7.75, 8.72, 15.72, 17.06, and 20.98◦, in- dicating similarity to the diffractogram of the CUR polymorph form 1, which has a monoclinic crystal structure (Sanphui et al., 2011) . INIC has shown a diffractogram with sharp peaks at 7.59, 20.60, 25.66, 26.38, and 30.74◦, which indicates agree- ment with the literature (Liu et al., 2021) . The solid CUR-INIC has a PXRD diffractogram with a new pattern different from the CUR and INIC diffractograms. New diffraction peaks appear on the CUR-INC diffractogram, namely at 15.00, 16.22, and 22.89◦. The presence of new peaks on the CUR-INIC diffractogram indicates that the solid CUR-INIC is not a physical mixture of CUR and INIC but is a new crystalline solid with a different structure resulting from Figure 1. PXRD Difractogram of (a) CUR, (b) INIC, and (c) CUR-INIC the interaction between CUR and INIC (Pantwalawalkar et al., 2021) . 3.2 DSC Thermogram The DSC thermograms of CUR, INIC, and CUR-INIC are shown in Figure 2. The thermogram of CUR shows an en- dothermic peak at 186.1◦C (ΔH = 119.25 J/g), while the ther- mogram of INIC also shows an endothermic peak at 156.9◦C (ΔH = 175.24 J/g). The temperatures of the endothermic peaks on the CUR and INIC thermograms are correlated with melting points that agree with the literature Ketkar et al. (2016) and Abdelkader et al. (2022) . Figure 2. DSC Thermogram of (a) CUR, (b) INIC, and (c) CUR-INIC On the CUR-INIC thermogram, two endothermic peaks appear, namely at 149.2◦C (ΔH = 32.742 J/g) and 160.1◦C (ΔH = 76.344 J/g). The first endothermic peak (149.2◦C) represents the melting of the eutectic mixture, while the second endothermic peak (160.1◦C) represents the melting of the CUR-INIC cocrystal (Pantwalawalkar et al., 2021) . The CUR- © 2023 The Authors. Page 503 of 508 Wicaksono et. al. Science and Technology Indonesia, 8 (2023) 501-508 INIC cocrystal solid showed melting at temperatures between the melting temperatures of CUR and INIC, indicating that CUR and INIC molecules formed intermolecular interactions in CUR-INIC solids with a different arrangement compared to CUR and INIC, resulting in a new crystalline solid phase (Satapathy et al., 2021) . The molecular arrangement of CUR-INIC cocrystal solids determines the formation of crystal packing and crystal lattice energy in CUR-INIC cocrystal solids (Kilinkissa et al., 2020; Volodin et al., 2019; Ejarque et al., 2021). Packing and crys- tal lattice energy affect the melting temperature of the solids, and cocrystals generally have melting temperatures between those of their constituents (Qiao et al., 2011; Salahinejad et al., 2013; Gamidi et al., 2018). The CUR- INIC cocrystal exhibits a lower melting point than pure CUR solids because the INIC molecules in the cocrystal structure are thought to produce a repeating pattern of the crystal lattice with more significant vari- ations in intermolecular forces, thereby lowering the melting point (Salahinejad et al., 2013; Gamidi et al., 2018). The pat- tern of the thermogram and melting point of the CUR-INIC cocrystal shows similarities to the CUR-ascorbic acid cocrystal (Pantwalawalkar et al., 2021) . 3.3 FTIR Spectra The FTIR spectra of CUR, INIC, and CUR-INIC are shown in Figure 3. The CUR spectra showed an absorption peak at 3500 cm−1, indicating stretching vibrations of O-H phenolic, 1626 cm−1 associated with stretching vibrations of C=C and C=O, 1601 cm−1 associated with C=C stretching vibrations of the aromatic ring, 1505 cm−1 associated with vibrations of C=O, 1262 cm−1 associated with vibrations of aromatic C-O (enol groups), and 1026 cm−1 associated with vibrations of C-O-C group (Sharma et al., 2022) . INIC has a spectrum with absorption peaks at 3363 and 3177 cm−1, showing stretching vibrations of asymmetric and asymmetric N-H, 1657 cm−1 as- sociated with stretching vibrations of C=O amide, 1621 cm−1 associated with bending vibrations of amide N-H, and 1408 cm−1 is related to the stretching vibrations of C-N amide (Fer- reira et al., 2022) . In the CUR-INIC spectra, it appears as a combination of the absorption peaks from the CUR and INIC spectra. How- ever, there were shifts in wave number values at several ab- sorption peaks compared to the individual absorption peaks of CUR and INIC. The CUR absorption peaks in the CUR-INIC spectra, which showed a shift, were 3500 to 3507 cm−1, 1262 to 1275 cm−1, and 1026 to 985 cm−1. Meanwhile, the absorp- tion peaks of INIC in the CUR-INIC spectra showed a shift, 3363 to 3329 cm−1, 1657 to 1679 cm−1, 1621 to 1626 cm−1, and 1408 to 1413 cm−1. The absorption peaks of CUR-INIC, which are experiencing a shift, are the absorption peaks of the donor and acceptor groups of hydrogen bonds. The shift of the absorption peaks indicates that in CUR- INIC, there has been a hydrogen bonding interaction involving the phenolic O-H, aromatic C-O (enol), and C-O-C groups of the CUR molecules with the C=O, N-H, and C-N groups of the INIC molecules (Pantwalawalkar et al., 2021) . 3.4 SEM Images SEM is useful for analyzing the morphology and surface to- pography of materials. SEM images of CUR, INIC, and CUR- INIC are shown in Figure 4. SEM images have shown that the shape of the CUR particles is a rectangular plate with a smooth surface, while the shape of the INIC particles is a rod with a wavy surface. SEM images of CUR-INIC particles have shown a different shape and appearance than CUR and INIC particles. CUR-INIC particles have an irregular shape resulting from aggregating a set of particles, and there are no visible traces of CUR and INIC particles. The aggregates of CUR-INIC particles form a morphology and surface topography with a hollow structure indicating a larger surface area. The char- acteristics of particles with a hollow structure generally have more excellent solubility properties than particles with a dense structure (Agarwal et al., 2020; Kawano et al., 2021). Based on the results of the analysis with PXRD, DSC, FTIR, and SEM, it was concluded that CUR and INIC, after prepa- ration, formed a new solid phase with a different molecular arrangement compared to the starting material. The CUR and INIC molecules in the CUR-INIC solid form a hydrogen bond interaction, resulting in a new crystal structure. The new crystal structure of the CUR-INIC cocrystal is indicated in the PXRD diffractogram and FTIR spectra. The CUR-INIC cocrystal shows different thermodynamic and physical properties com- pared to each constituent material, as shown in the analysis results by DSC and SEM. 3.5 Solubility The nature of solubility in water is a critical parameter that de- termines the absorption and bioavailability of an API. CUR is poorly soluble in water, so it is difficult to absorb by the gastroin- testinal tract, causing its bioavailability to be below 1% (Suresh and Nangia, 2018; Peng et al., 2021). The solubility test re- sults showed that CUR had a solubility in water of 5.05±0.07 `g/mL, while the CUR-INIC cocrystal in the water had a sol- ubility of 73.1±0.23 `g/mL. These results indicated that the cocrystallization of CUR-INIC has increased the solubility of CUR about 14 times. The solubility of a crystalline solid is strongly influenced by its crystal structure and packing, which is related to the crys- tal lattice energy. Crystalline solids with lower lattice energy are made up of molecules bonded with weaker energy, and during the dissolution process, water molecules more easily hydrate them (Kuleshova et al., 2013; Thakuria et al., 2013). Cocrystals are formed from molecules of API and coformer that make up the crystal lattice. Molecules of API and coformer in cocrystals interact with non-covalent bonds, such as hydro- gen bonds, forming new structures and packings with different lattice energies than the starting materials (Guo et al., 2018) . Based on the results of the diffractogram, the CUR used in this study is a CUR polymorph form 1 with a monoclinic structure known to have very low water solubility (Sanphui © 2023 The Authors. Page 504 of 508 Wicaksono et. al. Science and Technology Indonesia, 8 (2023) 501-508 Figure 3. FTIR Spectra of (a) CUR, (b) INIC, and (c) CUR-INIC Figure 4. SEM Images of (a) CUR, (b) INIC, and (c) CUR-INIC (15 kV, ×1000) et al., 2011) . Sanphui et al. (2011) modified the CUR crystal form and produced CUR polymorph forms 2 and 3 with an orthorhombic structure with a higher dissolution rate than CUR form 1 (monoclinic). CUR in the CUR-INIC cocrystal exhibited a higher solubility than the initial CUR, presumably due to lowering the crystal lattice energy of the CUR-INIC cocrystal. The intermolecular interaction of INIC with CUR changes the structure and arrangement of the crystal lattice of CUR so that the cocrystal solid formed has a lower lattice energy. Cocrystals with lower lattice energy become more easily hydrated by water molecules, increasing their solubility and dissolution rate (Ozaki et al., 2014; Docherty et al., 2015; Bergström and Larsson, 2018). 3.6 Anti-Inflammatory Activity Changes in the paw thickness of mice after being induced with 1% carrageenan are shown in Figure 5. Changes in paw thick- ness indicate the occurrence of edema, which correlates with inflammation. In group I (control), changes in paw thickness occurred after 1% carrageenan administration, increased until the 4th hour, and then decreased at the 5th hour. In groups II (CUR group) and III (CUR-INIC group), the paw thickness increased until about 1 hour after 1% carrageenan adminis- tration. Then the paw thickness decreased until the 5th hour. Changes in paw thickness of group I (control) at 1 to 5 hours showed a significant difference (p<0.05) compared to changes in paw thickness from the II and III groups. The changes in paw thickness show that administration of 1% carrageenan has induced edema in all groups of mice. In II and III groups, there was a significant (p<0.05) decrease in edema (at 1 to 5 hours) compared to group I (control) as a result of the administration of CUR and CUR-INIC cocrystals. The decrease in edema has proven that administering CUR and CUR-INIC cocrystals in II and III groups has an anti-inflammatory effect in mice. The percentage of edema inhibition at 5 hours showed that in the II group (CUR), there was an inhibition of edema of © 2023 The Authors. Page 505 of 508 Wicaksono et. al. Science and Technology Indonesia, 8 (2023) 501-508 Figure 5. Changes of the Paw Thickness of Mice of (a) Control Group, (b) CUR Group, and (c) CUR-INIC Group 43.90±2.82%, while in the III group (CUR-INIC cocrystal), there was an inhibition of edema of 57.32±2.44%. The per- centage of edema inhibition indicates that administration of CUR in the form of CUR-INIC cocrystals (equivalent to CUR 200 mg/kg BW) had significantly higher inhibition (130%) of edema than administration of initial CUR without cocrystal- lization. The solubility of the CUR-INIC cocrystal increased signifi- cantly (p<0.05) compared to the solubility of the initial CUR. The increase in the solubility of the CUR-INIC cocrystal is thought to cause the amount of dissolved CUR in the diges- tive tract of mice to be greater than that of group II (CUR). The amount of API dissolved in the digestive tract is gener- ally directly proportional to the API absorbed, which has a pharmacological effect (Khames, 2017) . Thus, it can be esti- mated that the increased anti-inflammatory activity in group III (CUR-INIC cocrystal) compared to group II (CUR) is due to the increased solubility of CUR in the CUR-INIC cocrystal (Granata et al., 2017; He et al., 2019). 4. CONCLUSIONS Cocrystallization of CUR with INIC coformer produces CUR- INIC cocrystals, which exhibit novel crystalline solid character- istics. The PXRD diffractogram of the CUR-INIC cocrystal has a different pattern of diffraction peaks compared to the indi- vidual diffractograms of CUR and INIC. The molecules of the constituent materials in the CUR-INIC cocrystal form inter- molecular interactions of hydrogen bonds which produce a new solid phase with a melting point of 160.1◦C. The CUR-INIC cocrystal showed a solubility in water of 73.1±0.23 `g/mL. In comparison, the initial CUR showed a solubility of only 5.05±0.07 `g/mL, so the cocrystallization of CUR with INIC coformer could increase the solubility of CUR by 14 times. CUR-INIC cocrystal showed anti-inflammatory activity in mice 130% stronger than initial CUR. 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Page 508 of 508 INTRODUCTION EXPERIMENTAL SECTION Chemicals and Equipment Methods Cocrystallization of CUR-INIC Characterization with PXRD Characterization with DSC Characterization with FTIR Characterization with SEM Solubility Test Evaluation of Anti-Inflammatory Activity Statistical Analysis RESULTS AND DISCUSSION PXRD Diffractogram DSC Thermogram FTIR Spectra SEM Images Solubility Anti-Inflammatory Activity CONCLUSIONS ACKNOWLEDGMENT