Host-guest complex of β-cyclodextrin and pluronic F127 with Luteolin: Physicochemical characterization, anti-oxidant activity and molecular modeling studies

β-Cyclodextrin metal-organic framework as a green carrier to improve the dissolution, bioavailability, and liver protective effect of luteolin

The incidence of acetaminophen-induced liver injury has increased, but effective prevention methods are limited. Although luteolin has hepatoprotective activity, its low solubility and bioavailability limit its applications. Cyclodextrin metal-organic frameworks (CD-MOFs) possess 3D-network structures and large inner cavities, which make them excellent carriers of poorly soluble drugs. In this study, we used CD-MOFs as carriers to improve the dissolution of luteolin and assessed their antioxidant activity, bioavailability, and hepatoprotective effects. Luteolin was loaded into β-CD-MOF, γ-CD-MOF, β-CD, and γ-CD, and characterized by powder X-ray diffractometry (PXRD) and thermogravimetric analysis (TGA). Our results showed that luteolin-β-CD-MOF was the most stable. The main driving forces were hydrogen bonds and van der Waals forces, as determined by molecular simulation. The loading capacity of luteolin-β-CD-MOF was 14.67 wt%. Compared to raw luteolin, luteolin-β-CD-MOF exhibited a 4.50-fold increase in dissolution and increased antioxidant activity in vitro. Luteolin-β-CD-MOF increased the bioavailability of luteolin by approximately 4.04- and 11.07-fold in healthy rats and liver injured rats induced by acetaminophen in vivo, respectively. As determined by biochemical analysis, luteolin-β-CD-MOF exhibited a better hepatoprotective effect than raw luteolin in rats with acetaminophen-induced liver injury. This study provides a new approach for preventing acetaminophen-mediated liver damage.

The dissolution of p-methoxycinnamic acid-β-cyclodextrin inclusion complex produced with microwave irradiation

Background: p-methoxycinnamic acid (pMCA) is an ethyl p-methoxycinnamic derivative, which is the largest active ingredient in the rhizome of the kencur (Kaempferia galanga L) plant. Several studies reported that the compound has anti-inflammatory activity but has low solubility in water. The formation of a pMCA-β-cyclodextrin (βCD) inclusion complex with a molar ratio of 1:1 can increase its solubility. The formation of inclusion complexes with conventional methods requires a long time and the yield value is not optimal. Objective: This study aims to evaluate the dissolution of the pMCA-βCD inclusion complex produced using the microwave irradiation method. Methods: The product was manufactured with chloroform solvent and a power of 400 watts (power 80%). It was then evaluated using the Differential Thermal Analysis (DTA) every 2 minutes until the 8th minute. The reaction was complete after 4 minutes of treatment with a yield of 96.5%. The obtained inclusion complexes were evaluated using DTA, FTIR, and PXRD. Subsequently, a dissolution test was carried out using a type 2 apparatus in distilled water medium of pH 6.8±0.05 at 37±0.5°C. Results: The results showed that there was a change in the melting temperature profile, infrared spectra, and crystallinity of the product. An 89.18% dissolution was also obtained within 60 minutes, which was twice that of pMCA compounds. Conclusion: From the results of the study, it can be concluded that the formation of pMCA-βCD inclusion complexes using the microwave irradiation method is capable of providing high-yield values in a short time.

Preparation and Evaluation of Amorphous Solid Dispersions for Enhancing Luteolin's Solubility in Simulated Saliva

Luteolin (LUT), a bioactive flavonoid, possesses various pharmacological properties, including antioxidant, antimicrobial, anti-allergic, cardio-protective, and anti-cancer activity. Among them, LUT's administration for the treatment of periodontal disease is very promising. However, its low water solubility magnifies the challenge of formulating LUT into an effective dosage form. In this vein, the aim of the present study examines the preparation of amorphous solid dispersions (ASD) for the solubility improvement of LUT in saliva. At first, the physicochemical properties of the active pharmaceutical ingredient (API) were studied before the selection of the most suitable ASD matrix/carrier. For this reason, six commonly used polymeric ASD matrix/carriers (namely, povidone, PVP; copovidone, coPVP; hydroxypropyl cellulose, HPC-SL; hydroxypropyl methyl cellulose acetate succinate, HPMC-AS; Eudragit^® RS, Eud-RS; and Soluplus^®, SOL) were screened via the film casting method, as to whether they could suspend the drug's recrystallization. The most promising matrix/carriers were then evaluated, based on their ability to inhibit LUT's precipitation after its solubilization, via the solvent shift method. Based on both screening methods, it was determined that PVP was the most promising matrix/carrier for the preparation of LUT's ASDs. Hence, in a further step, after the successful testing of components' miscibility, LUT-PVP ASDs were prepared via the solvent evaporation method. These systems (examined via powder X-ray diffractometry, pXRD) showed full API amorphization immediately after preparation and excellent physical stability (since they were stable after 3 months of storage). The study of LUT-PVP ASD's ATR-FTIR (Attenuated Total Reflectance-Fourier Transform Infrared) spectra demonstrated strong H-bonds between the molecules of the drug and the matrix/carrier, while molecular dynamics (MD) simulations were able to shed light on these drug-matrix/carrier interactions, at a molecular level. Finally, in vitro dissolution studies in simulated saliva proved that the prepared ASDs were able to significantly enhance LUT's dissolution profile. Hence, according to findings of the present work, the preparation of LUT-ASDs utilizing PVP as the polymeric matrix/carrier is regarded as a highly promising technique for the improvement of API's solubility in the oral cavity.

Fabrication and Characterization of β-Cyclodextrin/Mosla Chinensis Essential Oil Inclusion Complexes: Experimental Design and Molecular Modeling

Essential oils (EOs) are primarily isolated from medicinal plants and possess various biological properties. However, their low water solubility and volatility substantially limit their application potential. Therefore, the aim of the current study was to improve the solubility and stability of the Mosla Chinensis (M. Chinensis) EO by forming an inclusion complex (IC) with β-cyclodextrin (β-CD). Furthermore, the IC formation process was investigated using experimental techniques and molecular modeling. The major components of M. Chinensis 'Jiangxiangru' EOs were carvacrol, thymol, o-cymene, and terpinene, and its IC with β-CD were prepared using the ultrasonication method. Multivariable optimization was studied using a Plackett-Burman design (step 1, identifying key parameters) followed by a central composite design for optimization of the parameters (step 2, optimizing the key parameters). SEM, FT-IR, TGA, and dissolution experiments were performed to analyze the physicochemical properties of the ICs. In addition, the interaction between EO and β-CD was further investigated using phase solubility, molecular docking, and molecular simulation studies. The results showed that the optimal encapsulation efficiency and loading capacity of EO in the ICs were 86.17% and 8.92%, respectively. Results of physicochemical properties were different after being encapsulated, indicating that the ICs had been successfully fabricated. Additionally, molecular docking and dynamics simulation showed that β-CD could encapsulate the EO component (carvacrol) via noncovalent interactions. In conclusion, a comprehensive methodology was developed for determining key parameters under multivariate conditions by utilizing two-step optimization experiments to obtain ICs of EO with β-CD. Furthermore, molecular modeling was used to study the mechanisms involved in molecular inclusion complexation.

Formulation and characterization of eprosartan mesylate and β-cyclodextrin inclusion complex prepared by microwave technology

The goal of this work was to improve the aqueous solubility and dissolution rate of eprosartan mesylate by preparing inclusion complex of drug with β-cyclodextrin (β-CD) by microwave technique. In order to determine the solubility of eprosartan, phase solubility was determined and dissolution study was also conducted. Further, analytical techniques for instance, particle size distribution, differential scanning calorimetry, powder X-ray diffraction, scanning electron microscopy, Fourier-transform infrared spectroscopy, and nuclear magnetic resonance spectroscopy were used for the characterization of inclusion complex. In addition, the binding pattern of eprosartan with the β-CD was investigated by molecular modeling study. Phase solubility study revealed that approximately 4.48 folds improvement in the solubility of drug was noted with β-CD (10 mM). The estimated stability constant (K_c) values for eprosartan:β-CD binary mixture was found to be 280.78 M^–1. The prepared inclusion complex of drug with β-CD presented better drug release profile (62.96 ± 2.01% in 1 h) as compared to their physical mixture (41.41 ± 1.77% in 1 h) or drug per se (29.97 ± 3.13%). The inclusion complex demonstrated different features and properties from pure drug, and we inferred that this could be due to the inclusion of drug into cyclodextrin cavity that confirmed by different analytical method. Molecular modeling study demonstrated a good affinity of eprosartan to entangle to β-CD. The outcomes have shown that guest molecule has many significant interactions with the host molecule. These observations are very interesting and may be a valuable approach to improve the solubility and in turn the bioavailability of eprosartan.

Cannabidiol/hydroxypropyl-β-cyclodextrin inclusion complex: structure analysis, release behavior, permeability, and bioactivity under in vitro digestion

The inclusion complex of CBD greatly improved its release performance and bioactivity.

Preparation and In Vitro-In Vivo Evaluation of Luteolin Loaded Gastroretentive Microsponge for the Eradication of Helicobacter pylori Infections

The current study aimed to develop a luteolin gastric floating microsponge for targeting Helicobacter pylori. The microsponge formulations were prepared by a quasi-emulsion method, and then evaluated for various physicochemical variables. The best microsponge was further assessed for drug-polymer interactions, surface morphology, in vivo floating, and in vitro anti H. pylori activity. The formulation which exhibited comparatively good production yield (64.45% ± 0.83), high entrapment efficiency (67.33% ± 3.79), prolonged in vitro floating time (>8 h), and sustained in-vitro drug release was selected as the best microsponge. The SEM study revealed that the best microsponge was spherical in shape and has a porous surface with interconnecting channels. DSC and XRD studies demonstrated the dispersion of luteolin in the polymeric matrix of the microsponge. Ultrasonography confirmed that the best microsponge could in the rat stomach for 4 h. The in vitro MIC results indicate that the anti H. pylori activity of the best microsponge was almost doubled and more sustained compared to pure luteolin. To conclude, it can be said that the developed luteolin gastric floating microsponge could be a better option to effectively eradicate H. pylori infections and the histopathological and pharmacodynamic assessments of our best microsponge can be expected to provide a rewarding outcome.

Development and Evaluations of Transdermally Delivered Luteolin Loaded Cationic Nanoemulsion: In Vitro and Ex Vivo Evaluations

Introduction: Luteolin (LUT) is natural flavonoid with multiple therapeutic potentials and is explored for transdermal delivery using a nanocarrier system. LUT loaded cationic nanoemulsions (CNE1–CNE9) using bergamot oil (BO) were developed, optimized, and characterized in terms of in vitro and ex vivo parameters for improved permeation. Materials and methods: The solubility study of LUT was carried out in selected excipients, namely BO, cremophor EL (CEL as surfactant), labrasol (LAB), and oleylamine (OA as cationic charge inducer). Formulations were characterized with globular size, polydispersity index (PDI), zeta potential, pH, and thermodynamic stability studies. The optimized formulation (CNE4) was selected for comparative investigations (% transmittance as %T, morphology, chemical compatibility, drug content, in vitro % drug release, ex vivo skin permeation, and drug deposition, DD) against ANE4 (anionic nanoemulsion for comparison) and drug suspension (DS). Results: Formulations such as CNE1–CNE9 and ANE4 (except CNE6 and CNE8) were found to be stable. The optimized CNE4 based on the lowest value of globular size (112 nm), minimum PDI (0.15), and optimum zeta potential (+26 mV) was selected for comparative assessment against ANE4 and DS. The %T values of CNE1–CNE9 were found to be ˃95% and CEL content slightly improved the %T value. The spherical CNE4 was compatible with excipients and showed % total drug content in the range of 97.9–99.7%. In vitro drug release values from CNE4 and ANE4 were significantly higher than DS. Moreover, permeation flux (138.82 ± 8.4 µg/cm²·h), enhancement ratio (8.23), and DD (10.98%) were remarkably higher than DS. Thus, ex vivo parameters were relatively high as compared to DS which may be attributed to nanonization, surfactant-mediated reversible changes in skin lipid matrix, and electrostatic interaction of nanoglobules with the cellular surface. Conclusion: Transdermal delivery of LUT can be a suitable alternative to oral drug delivery for augmented skin permeation and drug deposition.

Solubility enhancement of poorly water soluble domperidone by complexation with the large ring cyclodextrin

The water solubility of domperidone (DMP) could be improved by complexation with large ring cyclodextrins (LR-CDs). LR-CDs contain a relatively hydrophobic cavity that is capable of entrapping the molecules to form inclusion complexes. The complex formation capability of mixture LR-CDs having a degree of polymerization (DP) of 22-48, with DMP was investigated. The phase solubility profile of mixture LR-CD/DMP was classified as A_N-type, resulting in increased DMP solubility in water by 3-fold. Various physicochemical techniques confirmed the mixture LR-CD/DMP complex formation. Single LR-CD with DP of 26, 27, 28, 29, 30, 33 and 34 (CD26 ~ CD34) were isolated from LR-CD mixtures using ODS column for HPLC separation. The CD33/DMP complex has demonstrated the most significant improvement compared to other single LR-CD complexes with a 2.7-fold increase in DMP solubility. The molecular dynamic result revealed that DMP formed stable complexes with CD33 by positioned fully encapsulated inside the cavity and covered by 13-14 subunits of CD33.

Enhanced solubility of Albendazole in Cyclodextrin Inclusion Complex: A Molecular Modeling Approach and Physicochemical Evaluation

BACKGROUND

Albendazole (ABZ) is the drug of choice for the treatment of a variety of human and veterinary parasites. However, it has low aqueous solubility and low bioavailability. Cyclodextrins (CD) are pharmaceutical excipients with the ability to modulate the solubilization property of hydrophobic molecules.

OBJECTIVE

To analyze (Autodock Vina software and CycloMolder platform) the formation of inclusion complexes between ABZ, β-cyclodextrin (β-CD) and its derivatives, Methyl-β-cyclodextrin (M-β-CD) and Hydroxypropyl-β-cyclodextrin (HP-β-CD), through in vitro and in silico studies.

METHODS

The most stable inclusion complexes were produced by the kneading method and characterized by Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC), X-Ray Diffraction (XRD), determination of the ABZ content, and in vitro dissolution profile.

RESULTS

Molecular modeling revealed that inclusion complexes between HP-β-CD:ABZ (in the proportion 1:1 and 2:1) presented the lowest formation energy and the highest number of intermolecular interactions, showing that the use of more cyclodextrins does not provide any gain in the stability of the complex. Through the characterization tests, the complexes experimentally obtained by kneading method demonstrated a highly suggestive method, including ABZ in HP-β-CD in both molar proportions; The results of this study showed suppression of bands in the infrared spectrum, displacement of the drug's melting temperature in DSC, crystallinity halos instead of the characteristic peaks of ABZ crystals in the XRD and a release of more than 80% of ABZ in less than 5 minutes, beyond dissolution efficiency of up to 92%.

CONCLUSION

In silico studies provided a rational selection of the appropriate cyclodextrin, enabling the elaboration of more targeted complexes, decreasing time and costs to elaborate on new formulations that increase the oral biodisponibility of ABZ.

Effect of Modifications in Poly (Lactide-co-Glycolide) (PLGA) on Drug Release and Degradation Characteristics: A Mini Review

The use of PLGA in the pharmaceutical industry has only increased as we move towards more and more advanced delivery carrier systems. The qualities of PLGA like biocompatibility, biodegradability and a tunable degradation and drug release has only helped in keeping up the release requirements desired for various delivery platforms. Fine-tuning the release and degradation rate is gaining more and more attention as researchers keep pushing the boundaries of novel delivery carriers. Various experiments are being performed to understand the degradation behavior drug of PLGA under various physiological and process-related conditions. The understanding of these parameters has helped formulate various ways one can fine-tune the properties that can lead to the release of active ingredients encapsulated within. Various techniques have been tried and tested including modifications like chemical modifications, physical blending and surface modifications and have found to be effective means of release modulation in delivery systems like parenteral, orals, topicals and tissue engineering scaffolds. In this review, all these experiments and implications thereon have been discussed in detail.

Formulation of Piperine Ternary Inclusion Complex Using β CD and HPMC: Physicochemical Characterization, Molecular Docking, and Antimicrobial Testing

The present study was designed to evaluate the effect of hydroxyl propyl methyl cellulose (HPMC) on the complexation efficiency and dissolution of piperine (PPR) and β cyclodextrin (β CD) complex. The binary and ternary inclusion complexes were prepared using solvent evaporation and microwave irradiation methods. The samples were further evaluated for physicochemical evaluation, morphology, antimicrobial, and antioxidant activities. The binary and ternary samples showed high stability constant (Ks) value and complexation efficiency (CE). The dissolution study results revealed marked enhancement in the release of the binary inclusion complex and ternary inclusion complex compared to pure PPR. Fourier transform infrared (FTIR), nuclear magnetic resonance (NMR), and molecular docking results confirm the complex formation. X-ray powder diffractometry (XRD) and scanning electron microscopy (SEM) data revealed modification in the structure of PPR. 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging and antimicrobial results showed enhanced activity in the PPR complex in comparison to pure PPR. In conclusion, a remarkable enhancement in dissolution, antioxidant and antimicrobial activities were attained due to marked improvement in solubility through complexation of PPR with HPMC/β CD.

Formulation and Evaluation of Supramolecular Food-Grade Piperine HP β CD and TPGS Complex: Dissolution, Physicochemical Characterization, Molecular Docking, In Vitro Antioxidant Activity, and Antimicrobial Assessment

The purpose of the present study was to improve the aqueous solubility, dissolution, and antioxidant activity of the water-insoluble drug piperine (PIP). The study was performed by preparing PIP binary inclusion complex (PIP BIC) and piperine ternary inclusion complex (PIP TIC) by different methods. The effect of a hydrophilic auxiliary substance (TPGS) was assessed with addition to PIP and hydroxypropyl beta cyclodextrin (HP β CD) complex. The phase solubility study was performed to evaluate the complexation efficiency and stability constant. The aqueous solubility, dissolution, physicochemical assessment, antioxidant activity, antimicrobial activity, and molecular docking were further evaluated to check the effect of the complexation of PIP. The stability constant (Ks) value was found to be 238 and 461 M⁻¹ for the binary and ternary inclusion complex. The dissolution study results showed a marked enhancement of release in comparison to pure drug. XRD and SEM studies revealed the presence of more agglomerated and amorphous structures of PIP, which confirmed the formation of complexes. The results of DPPH radical scavenging and antimicrobial activity showed a significant (p < 0.05) enhancement in scavenging activity for PIP TIC (microwave irradiation (MI)). The docking studies have revealed that the binding affinity of TPGS at the PIP-HP β CD complex was −5.2 kcal/mol.

Etoposide Amorphous Nanopowder for Improved Oral Bioavailability: Formulation Development, Optimization, in vitro and in vivo Evaluation

Introduction

Etoposide refers to a derivative of podophyllotoxin, which plays an important role in the treatment of cancer due to its prominent anti-tumor effect. As a BCS IV drug, etoposide exhibits insufficient aqueous solubility and permeability, thereby limiting its oral absorption. To enhance the oral bioavailability of etoposide, this study developed an amorphous nanopowder.

Methods

Based on preliminary screening and experimental design, the stabilizer and preparation process of etoposide nanosuspension were explored. Subsequently, using a Box–Behnken design, the effects of independent factors (ultrasonication time, ratio of two phases and stabilizer concentration) on response variables (particle size and polydispersity index) were studied, and then the formulation was optimized. Finally, nanosuspension was further freeze dried with 1% of mannitol resulting in the formation of etoposide amorphous nanopowder.

Results

The optimized etoposide nanopowder showed as spherical particles with an average particle size and polydispersity index of 211.7 ± 10.4 nm and 0.125 ± 0.028. X-ray powder diffraction and differential scanning calorimetry confirmed the ETO in the nanopowder was amorphous. Compared with coarse powder and physical mixture, etoposide nanopowder achieved significantly enhanced saturated solubility and dissolution in various pH environments. The C_max and AUC_0–t of etoposide nanopowder after oral administration in rats were respectively 2.21 and 2.13 times higher than the crude etoposide suspension. Additionally, the T_max value of nanopowder was 0.25 h, compared with 0.5 h of reference group.

Discussion

In the present study, the optimized amorphous nanopowder could significantly facilitate the dissolution and oral absorption of etoposide and might act as an effective delivery method to enhance its oral bioavailability.

Formulation of Curcumin-β-cyclodextrin-polyvinylpyrrolidone supramolecular inclusion complex: experimental, molecular docking, and preclinical anti-inflammatory assessment

This research planned to ameliorate an aqueous solubility and dissolution of Curcumin (CUR) by the formulation of inclusion complex with β-cyclodextrin (β-CD) and polyvinylpyrrolidone (PVP). The phase solubility study was performed to assess the solubility of CUR. The prepared CUR complex assessed for dissolution study, physicochemical evaluation, in-vitro antioxidant activity, molecular modeling, and anti-inflammatory assessment. The pivotal findings of phase-solubility studies demonstrate apparent stability constant (Kc) and complexation efficiency (CE) values for CUR-β-CD and CUR-β-CD-PVP complex was 175.4 M ^-1, 1.15% and 833.3.2 M ^-1 and 5.21%, respectively. The characterization results revealed amorphization of crystalline state (CUR) into amorphous state. The maximum drug release found with the ternary CUR complex (F7), i.e. 45.41 ± 3.78% in 6 h study. The chemical shift in the NMR supports that the aromatic ring of CUR is completely complexed inside the β-CD cavity. The antioxidant activity of pure CUR was found to be 58.02 ± 2.21% and CUR ternary complex (F7) showed significantly higher activity to 96.02 ± 2.46%. The in-vivo effect of CUR complex (F7) was also found significantly higher than that of pure CUR. The molecular modeling study depicted that PVP increased the stability of the ternary complex by forming the link between CUR and β-CD. Thus, the ternary inclusion complex of CUR-β-CD-PVP could contribute as an innovative outcome in the enhancement of solubility and in-vivo activity.

Formulation of amorphous ternary solid dispersions of dapagliflozin using PEG 6000 and Poloxamer 188: solid-state characterization, ex vivo study, and molecular simulation assessment

The present study was designed to prepare dapagliflozin (DFG) loaded ternary solid dispersions (SDs) using the carrier blend polyethylene glycol 6000 (PEG 6000) and poloxamer 188 (PLX 188). The prepared DFG-SDs were evaluated for solubility study, physicochemical characterization and molecular simulation study. The prepared DFG-SDs showed significant higher solubility and dissolution vis-a-vis pure DFG and DFG physical mixture. The composition DFG:PEG:PLX (1:2.25:0.75 mM) showed the highest solubility (0.476 ± 0.016 mg/mL). The physicochemical characterization confirms the polymorphic transition of DFG from crystalline state to stable amorphous form. The prepared DFG-SDs showed a significantly higher dissolution (64.78 ± 2.34% to 78.41 ± 2.39%) than pure DFG (15.70 ± 3.54%). DFG-SD2 showed a significantly enhanced drug permeation (p<.05) (58.76 ± 4.65 µg/cm) as compared to pure DFG (14.97 ± 3.32 µg/cm). The molecular docking study result revealed a good hydrophobic interaction of DFG with the used carrier due to the lowest energy pose. The interaction occurs between the methylene bridges and the central hydrophobic chain of polyoxypropylene of the polymer. Therefore, DFG-SDs prepared by microwave irradiation method using hydrophilic carrier blend might be a promising strategy for improving the solubility and in vitro dissolution performance.

Stimulatory Effects of Soluplus® on Flufenamic Acid β-Cyclodextrin Supramolecular Complex: Physicochemical Characterization and Pre-clinical Anti-inflammatory Assessment

The present study demonstrates the solubility and dissolution of flufenamic acid (FLF)/β-cyclodextrin (β-CD)/Soluplus® supramolecular ternary inclusion complex. The binary and ternary inclusion complexes were prepared using solvent evaporation and the microwave irradiation method. The prepared inclusion complexes were evaluated for physicochemical characterization and anti-inflammatory activity using a murine paw edema mol. The phase solubility studies demonstrated 4.59-fold and 17.54-fold enhancements in FLF solubility with β-CD alone and β-CD:Soluplus® combination compared with pure FLF, respectively. The in vitro drug release results revealed a significant improvement (P < 0.05) in the release pattern compared with pure FLF. Maximum release was found with flufenamic acid binary and ternary complexes prepared using the microwave irradiation method, i.e., 75.23 ± 3.12% and 95.36 ± 3.23% in 60 min, respectively. The physicochemical characterization results showed complex formation and conversion of the crystalline form of FLF to an amorphous form. The SEM study revealed the presence of a more agglomerated and amorphous structure of the solid particles, which confirmed the formation of complexes. The anti-inflammatory effect of the complex was higher than pure FLF. Therefore, the FLF:β-CD:Soluplus® inclusion complex may be a very valuable formulation with improved solubility, dissolution, and anti-inflammatory effect.

Enhanced Dissolution of Luteolin by Solid Dispersion Prepared by Different Methods: Physicochemical Characterization and Antioxidant Activity

Luteolin (LT) is a poorly soluble bioactive compound that suffered bioavailability problems after oral administration. Hence, the aim of the proposed research work was to formulate and investigate various solid dispersions (SDs) of LT in order to enhance its dissolution and bioactivity. LT-SD was prepared using polyethylene glycol 4000 (PEG 4000) as a carrier at the mass ratios of 1:1, 1:2, and 1:4. LT-SD was prepared using different methods including fusion (FU), solvent evaporation (SE), and microwave irradiation (MI) methods. The prepared LT-SD was duly characterized in terms of differential scanning calorimetry (DSC), X-ray diffraction (XRD), scanning electron microscopy (SEM), infrared (IR) spectroscopy, and nuclear magnetic resonance (NMR) and evaluated for dissolution and in vitro antioxidant activity. The results of DSC, XRD, SEM, IR, and NMR suggested the formation of LT-SD. After 90 min of the dissolution study, the results displayed that the % release of LT from prepared SD was significantly higher compared with the pure LT and its physical mixture dispersion (PMD). LT-SD prepared using the MI method displayed the maximum release of LT (i.e., 97.78 ± 4.41%) at a 1:2 mass ratio of LT:PEG 4000. The LT-SD prepared using the SE method displayed the maximum release of 93.78 ± 3.98% at a mass ratio of 1:4 of LT:PEG 4000. The SD prepared by the MI method showed enhanced dissolution due to higher aqueous solubility and the reduction of particle size. The solid-state characterization studies (DSC, XRD, SEM, IR, and NMR studies) suggested the morphological conversion of LT into the amorphous form from the crystalline state. The results of the antioxidant study revealed that the formation LT-SD displayed significantly higher radical scavenging activity than the pure LT. Therefore, SD obtained using PEG 4000 could be a potential strategy for maximizing the solubility, in vitro dissolution, and therapeutic efficacy of LT.