Inclusion complexes of ketoconazole with beta-cyclodextrin: physicochemical characterization and in vitro dissolution behaviour of its vaginal suppositories

Binary and Ternary Inclusion Complexes of Niflumic Acid: Synthesis, Characterization, and Dissolution Profile

Although niflumic acid (NA) is one of the most used non-steroidal anti-inflammatory drugs, it suffers from poor solubility, low bioavailability, and significant adverse effects. To address these limitations, the complexation of NA with cyclodextrins (CDs) is a promising strategy. However, complexing CDs with low molecular weight drugs like NA can lead to low CE. This study explores the development of inclusion complexes of NA with 2-hydroxypropyl-β-cyclodextrin (2HP-β-CD), including the effect of converting NA to its sodium salt (NAs) and adding hydroxypropyl methylcellulose (HPMC) on complex formation. Inclusion complexes were prepared using co-evaporation solvent and freeze-drying methods, and their CE and Ks were determined through a phase solubility study. The complexes were characterized using physicochemical analyses, including FT-IR, DSC, SEM, XRD, DLS, UV-Vis, 1H-NMR, and 1H-ROESY. The dissolution profiles of the complexes were also evaluated. The analyses confirmed complex formation for all systems, demonstrating drug-cyclodextrin interactions, amorphous drug states, morphological changes, and improved solubility and dissolution profiles. The NAs-2HP-β-CD-HPMC complex exhibited the highest CE and Ks values, a 1:1 host-guest molar ratio, and the best dissolution profile. The results indicate that the NAs-2HP-β-CD-HPMC complex has potential for delivering NA, which might enhance its therapeutic effectiveness and minimize side effects.

Randomly Methylated β-Cyclodextrin Inclusion Complex with Ketoconazole: Preparation, Characterization, and Improvement of Pharmacological Profiles

As a powerful imidazole antifungal drug, ketoconazole's low solubility (0.017 mg/mL), together with its odor and irritation, limited its clinical applications. The inclusion complex of ketoconazole with randomly methylated β-cyclodextrin was prepared by using an aqueous solution method after cyclodextrin selection through phase solubility studies, complexation methods, and condition selection through single factor and orthogonal strategies. The complex was confirmed by FTIR (Fourier-transform infrared spectroscopy), DSC (differential scanning calorimetry), TGA (thermogravimetric analysis), SEM (scanning electron microscope images), and NMR (Nuclear magnetic resonance) studies. Through complexation, the water solubility of ketoconazole in the complex was increased 17,000 times compared with that of ketoconazole alone, which is the best result so far for the ketoconazole water solubility study. In in vitro pharmacokinetic studies, ketoconazole in the complex can be 100% released in 75 min, and in in vivo pharmacokinetic studies in dogs, through the complexation, the Cmax was increased from 7.56 μg/mL to 13.58 µg/mL, and the AUC0~72 was increased from 22.69 μgh/mL to 50.19 μgh/mL, indicating that this ketoconazole complex can be used as a more efficient potential new anti-fungal drug.

Enhancing Solubility and Dissolution Rate of Antifungal Drug Ketoconazole through Crystal Engineering

To improve the solubility and dissolution rate of the BCS class II drug ketoconazole, five novel solid forms in 1:1 stoichiometry were obtained upon liquid-assisted grinding, slurry, and slow evaporation methods in the presence of coformers, namely, glutaric, vanillic, 2,6-dihydroxybenzoic, protocatechuic, and 3,5-dinitrobenzoic acids. Single-crystal X-ray diffraction analysis revealed that the hydroxyl/carboxylic acid. . .N-imidazole motif acts as the dominant supramolecular interaction in the obtained solid forms. The solubility of ketoconazole in distilled water significantly increased from 1.2 to 2165.6, 321.6, 139.1, 386.3, and 191.7 μg mL-1 in the synthesized multi-component forms with glutaric, vanillic, 2,6-dihydroxybenzoic, protocatechuic, and 3,5-dinitrobenzoic acid, respectively. In particular, the cocrystal form with glutaric acid showed an 1800-fold solubility increase in water concerning ketoconazole. Our study provides an alternative approach to improve the solubility and modify the release profile of poorly water-soluble drugs such as ketoconazole.

Comprehensive Insights into Medicinal Research on Imidazole-Based Supramolecular Complexes

The electron-rich five-membered aromatic aza-heterocyclic imidazole, which contains two nitrogen atoms, is an important functional fragment widely present in a large number of biomolecules and medicinal drugs; its unique structure is beneficial to easily bind with various inorganic or organic ions and molecules through noncovalent interactions to form a variety of supramolecular complexes with broad medicinal potential, which is being paid an increasing amount of attention regarding more and more contributions to imidazole-based supramolecular complexes for possible medicinal application. This work gives systematical and comprehensive insights into medicinal research on imidazole-based supramolecular complexes, including anticancer, antibacterial, antifungal, antiparasitic, antidiabetic, antihypertensive, and anti-inflammatory aspects as well as ion receptors, imaging agents, and pathologic probes. The new trend of the foreseeable research in the near future toward imidazole-based supramolecular medicinal chemistry is also prospected. It is hoped that this work provides beneficial help for the rational design of imidazole-based drug molecules and supramolecular medicinal agents and more effective diagnostic agents and pathological probes.

Inclusion complex of ketoconazole and p-sulfonic acid calix[6]arene improves antileishmanial activity and selectivity against Leishmania amazonensis and Leishmania infantum

Many previous studies presented the effectiveness of ketoconazole (KTZ) against leishmaniasis. However, the bioavailability and therapeutic efficacy of free KTZ are limited due to its low aqueous solubility. In this study, an inclusion complex (IC6HKTZ) was prepared with p-sulfonic acid calix[6]arene (CX6SO₃H) to improve the solubility and efficacy of KTZ against Leishmania amazonensis and Leishmania infantum promastigotes. A linear increase in KTZ solubility as a function of CX6SO₃H concentration was verified using the phase-solubility diagram. The resulting diagram was classified as A_L-type and a 1:1 host-guest stoichiometry was assumed to prepare IC6HKTZ by freeze-drying. FTIR, TG/DSC, XRD, and solid-state ¹³C NMR spectroscopy analyses were performed to confirm the formation of IC6HKTZ. The solubility enhancement of KTZ by 120.00 μM CX6SO₃H was about 95 times. The IC₅₀ values of IC6HKTZ and free KTZ were 3.95 and 14.35 μM for Leishmania amazonensis and 6.74 and 17.47 μM for Leishmania infantum, respectively. The viability of DH82 macrophages was not affected by CX6SO₃H. These results show that CX6SO₃H is a new supramolecular carrier system that improves antileishmanial activities to KTZ for the treatment of cutaneous and visceral leishmaniasis.

Formulation and Characterization Studies of Inclusion Complexes of Voriconazole for Possible Ocular Application

In our study Voriconazole (VOR) was selected as an active agent to be used for the treatment of ocular fungal infections. To overcome low aqueous solubility of VOR, inclusion complexes with α-cyclodextrin (α-CD), β-cyclodextrin (β-CD), γ-cyclodextrin (γ-CD), hydroxypropyl-cyclodextrin (HP-CD), hydroxypropyl-β-cyclodextrin (HP-β-CD) hydroxypropyl-γ-cyclodextrin (HP-γ-CD), methyl-β-cyclodextrin (M-β-CD) and sulfabutylether-β-cyclodextrin (SBE-β-CD) were formulated. Characterization studies revealed that inclusion complexes were formulated successfully with lyophilization method. Aqueous solubility of VOR was enhanced up to 86 fold with the formation of the inclusion complexes. MTT analyses results revealed the safety of the complexes on 3T3 mouse fibroblast cell lines while Microbroth Dilution Method revealed the remarkable antifungal activities of the complexes. Analyses results revealed that inclusion complexes will overcome the poor ocular bioavailability of VOR resulting in efficient treatment of severe ocular fungal infections.

A supramolecular thermosensitive gel of ketoconazole for ocular applications: In silico, in vitro, and ex vivo studies

The incidence of corneal fungal infections continues to be a growing concern worldwide. Ocular delivery of anti-fungal drugs is challenging due to the anatomical and physiological barriers of the eye. The ocular bioavailability of ketoconazole (KTZ), a widely prescribed antifungal agent, is hampered by its limited aqueous solubility and permeation. In the study, the physicochemical properties of KTZ were improved by complexation with sulfobutylether-β-cyclodextrin (SBE-β-CD).KTZ-SBE-β-CD complex was studied in silico with docking and dynamics simulations, followed by wet-lab experiments.The optimized KTZ-SBE-β-CD complex was loaded into a thermosensitivein situ gel to increase corneal bioavailability. The supramolecular complex increased the solubility of KTZ by 5-folds and exhibited a 10-fold increment in drug release compared to the pure KTZ. Owing to the diffusion, thein situ gel exhibited a more sustained drug release profile. Theex vivocorneal permeation studies showed higher permeation from KTZ-SBE-β-CD in situ gel (flux of ∼19.11 µg/cm²/h) than KTZin situ gel (flux of ∼1.17 µg/cm²/h). The cytotoxicity assays and the hen's egg chorioallantoic membrane assay (HET-CAM) confirmed the formulations' safety and non-irritancy. In silico guided design of KTZ-SBE-β-CD inclusion complexes successfully modified the physicochemical properties of KTZ. In addition, the loading of the KTZ-SBE-β-CD complex into an in situ gel significantly increased the precorneal retention and permeation of KTZ, indicating that the developed formulation is a viable modality to treat fungal keratitis.

Characteristic of Cyclodextrins: Their Role and Use in the Pharmaceutical Technology

About 40% of newly-discovered entities are poorly soluble in water, and this may be an obstacle in the creation of new drugs. To address this problem, the present review article examines the structure and properties of cyclodextrins and the formation and potential uses of drug - cyclodextrin inclusion complexes. Cyclodextrins are cyclic oligosaccharides containing six or more D-(+)- glucopyranose units linked by α-1,4-glycosidic bonds, which are characterized by a favourable toxicological profile, low local toxicity and low mucous and eye irritability; they are virtually non-toxic when administered orally. They can be incorporated in the formulation of new drugs in their natural form (α-, β-, γ-cyclodextrin) or as chemically-modified derivatives. They may also be used as an excipient in drugs delivered by oral, ocular, dermal, nasal and rectal routes, as described in the present paper. Cyclodextrins are promising compounds with many beneficial properties, and their use may be increasingly profitable for pharmaceutical scientists.

Spray dried nanospheres for inclusion complexes of cefpodoxime proxetil with β-cyclodextrin, 2-hydroxypropyl-β-cyclodextrin and methyl-β-cyclodextrin: improved dissolution and enhanced antibacterial activity

OBJECTIVE

The aim of the current research was the development hard cellulose capsules containing cefpodoxime proxetil (CEF) (BCS-Class II) encapsulated nanospheres of inclusion complexes with β-CD, HP-β-CD and M-β-CD for efficient antibacterial therapy.

SIGNIFICANCE

The reason for this phenomenon is to bring an innovative approach to effective oral antimicrobial therapy with hard cellulose capsules containing spray dried nanospheres of CEF with β-CD, HP-β-CD and M-β-CD by means of increased solubility, dissolution rate and improved antibacterial efficiency with lower oral dose.

METHODS

Phase solubility analyses was performed to evaluate the drug/CD interaction, involving the stoichiometry and apparent stability constant. Following the preparation of inclusion complexes by spray-drying method, complexes were characterized for physical, solid-state and microbiological analyses. In vitro dissolution from hard cellulose capsules containing CEF and CEF/β-CD, CEF/HP-β-CD and CEF/M-β-CD complexes were performed.

RESULTS

According to AL type phase solubility curves, complexes were formulated as 1:1 molar ratio. The solubility of pure CEF was determined as 0.241 ± 0.002 mg mL-1, the solubility of inclusion complexes increased solubility from 3 to 5 times. The strong host-guest interaction was confirmed for CEF/HP-β-CD and CEF/M-β-CD complexes with SEM, DSC, FT-IR and 1H-NMR analyses. Inclusion complexes were more efficient on bacterial cells (2-4 fold) than pure CEF both Staphylococcus aureus, Escherichia coli and Klebsiella pneumoniae. Hard-cellulose capsules filled with inclusion complexes exhibited significantly faster release than unprocessed CEF.

CONCLUSION

Hard-cellulose capsules containing CEF/HP-β-CD and CEF/M-β-CD complexes appear to be superior alternative to commercially available CEF tablets for effective antibacterial therapy.

Cyclodextrins as carriers for volatile aroma compounds: A review

Cyclodextrins (CDs) are edible and biocompatible natural cyclic compounds that can encapsulate essential oils, flavours, volatile aroma compounds, and other substances. Complexation with CD-based materials improves the solubility and stability of volatile compounds and protects the bioactivity of the core materials. Therefore, the development of CD/volatile compound nanosystems is a key research area in the food, cosmetic, and pharmaceutical industries. This review briefly introduces the main types of natural CD; preparation methods of CD-based materials as carriers for aromatic substances or essential oils; characterisation methods used to calculate the interaction between CDs and volatile aroma compounds; molecular docking and simulation methods; and the application of CD-based nanosystems in different industries. The review aims to provide guidance for relevant practitioners in selecting appropriate CD materials and characterisation methods.

Simultaneous improvement of ketoconazole solubility, antifungal and antibiofilm activity by multicomponent complexation

Background: A novel multicomponent complex (MC) of ketoconazole (KET) with β-cyclodextrin (β-CD) and N-acetylcysteine (NAC) was developed with the purpose of improving the solubility as well as the antifungal and antibiofilm activity of KET against Candida albicans. Results & methodology: The interactions among the components were studied using nuclear magnetic resonance, thermal analysis, powder x-ray diffraction, infrared spectroscopy and scanning electron microscopy. Phase-solubility studies demonstrated a considerable increase in the solubility of the MC. An enhancement in antibiofilm and antifungal activity of MC was determined against C. albicans by XTT assay and microbiological studies. Conclusion: This MC, with improvements in the drug pharmaceutical performance, might have an important potential in the development of new pharmaceutical formulations of KET.

Preparation and in vitro characterization of rosuvastatin calcium incorporated methyl beta cyclodextrin and Captisol® inclusion complexes

Despite being the most effective hypolipidemic agent, poor physicochemical properties of Rosuvastatin calcium (RCa) remain challenging obstacles in the development of pharmaceutical dosage forms. Inclusion complexes (ICs) of RCa with cyclodextrin (CD) derivatives; methyl-beta-cyclodextrin (M-β-CD) and sulfobutylether-beta-cyclodextrin (SBE-β-CD; Captisol^®) were formulated by kneading and freeze-drying (lyophilization) methods. Pysicochemical properties of ICs were evaluated by SEM, DSC, XRD, FT-IR, ¹H-NMR analyses. Entrapment efficiency (EE), water solubility, in vitro release analyses were also performed. Safety and efficacy of the ICs were analyzed by cytotoxicity and permeation studies on Caco-2 cell lines. Both CDs indicated A_L type phase solubility diagrams showing that [1:1] molar ratio. Apparent stability constants (K_1:1) were found to be 60.93 M^-1 for M-β-CD and 158.07 M^-1 for Captisol^®. High EE in the range of 93.50-105.40% was achieved. Molar solubility of RCa was increased 3.7- and 4.1-fold with M-β-CD and Captisol^® ICs, respectively. In vitro release analyses have indicated the equivalence of dissolution profiles for M-β-CD and Captisol^® based ICs to that of pure RCa (f₂ > 50). Cytotoxicity studies on Caco-2 cell lines have revealed the safety of ICs for oral use. Permeability studies demonstrated that selected lyophilized F6 formulation has shown the best permeation rate with P_app value of 3.08 × 10^-7 cm·s^-1. Considering greater water solubility, lower toxicity, high efficiency of complexation as well as, RCa-like permeability and in vitro release behavior at pH 6.8; Captisol^® based lyophilized F6 formulation was selected as the best IC to be used in oral dosage forms of RCa.

Enhanced effect in combination of curcumin- and ketoconazole-loaded methoxy poly (ethylene glycol)-poly (ε-caprolactone) micelles

In order to enhance water-solubility and realize controlled release while keeping synergistic effects of ketoconazole and curcumin, drug-loaded methoxy poly (ethylene glycol)-b-poly (ε-caprolactone) micelles were prepared through thin membrane hydration method. Transmission electric microscopy and dynamitic light scattering characterization revealed the formation of ketoconazole- and curcumin-loaded micelles with an average size of 44.70nm and 39.56nm, respectively. The drug-loaded micelles endowed the two drugs' slow controlled release with water-solubility enhanced to 85 and 82000 folds higher than the corresponding raw drugs, respectively. In vitro antifungal activity test, chequerboard test and inhibition zone test indicated that efficacy of ketoconazole-loaded micelles was improved by introduction of curcumin-loaded micelles with a low fractional inhibitory concentration index (0.073). Biofilm formation inhibition assay also demonstrated that participation of curcumin-loaded micelles obviously strengthened the inhibition of fungal biofilms formation induced by ketoconazole-loaded micelles. The high synergistic activity of combinations is encouraging and the MPEG-PCL micelle is a potential drug delivery system for the combination of ketoconazole and curcumin.

Methoxy poly (ethylene glycol)-b-poly (δ-valerolactone) copolymeric micelles for improved skin delivery of ketoconazole

Ketoconazole is a broad spectrum imidazole antifungal drug. For the treatment of superficial fungal infections with ketoconazole, it needs to be permeated to deep skin layers. In order to develop topical formulation of ketoconazole for improving its skin deposition and water-solubility, ketoconazole-loaded methoxy poly (ethylene glycol)-b-poly (δ-valerolactone) micelles were developed through thin-film hydration method. Particle size, drug loading capacity, infrared spectrum and X-ray diffraction of drug-loaded micelles were characterized. The optimal drug formulation was selected for skin delivery and deposition investigation performed by use of mice skin, and its in vitro release and antifungal activity were also investigated. Penetration and distribution in the skin were also visualized using fluorescein-loaded micelles and fluorescence microscopy. The drug-loaded micelles were obtained with encapsulation efficiency of 86.39% and particle diameter of about 12 nm. The micelles made ketoconazole aqueous solubility increase to 86-fold higher than crude one. Ketoconazole-loaded micelles showed no skin permeation of ketoconazole, obviously enhance skin deposition and demonstrated similar antifungal activity as compared with marketed ketoconazole cream. Fluorescein-loaded micelles displayed higher skin deposition than fluorescein water solution. These results demonstrate that the MPEG-PVL micelle is a potential delivery system for ketoconazole in the field of skin delivery.

Synergetic skin targeting effect of hydroxypropyl-β-cyclodextrin combined with microemulsion for ketoconazole

The objective was to develop a ternary skin targeting system for ketoconazole (KET) using a combined strategy of microemulsion (ME) and cyclodextrin (HP-β-CD), i.e., KET-CD-ME, which exploits both virtues of cyclodextrin complex and ME to obtain the synergetic effect. KET-CD-ME was formulated using Labrafil M 1944 CS as oil phase, Solutol HS 15 as surfactant, Transcutol P as cosurfactant, and HP-β-CD solution as aqueous phase. The formulation of KET-CD-ME was optimized and the optimal formulation was characterized in terms of particle size, size distribution, pH value, and viscosity. Long term stability experiment showed that HP-β-CD could increase the physical stability of ternary system and KET chemical stability. Percutaneous permeation of KET from KET-CD-ME in vitro through rat skin was investigated in comparison with KET microemulsion (KET-ME), KET HP-β-CD inclusion solution (KET-CD), KET aqueous suspension, and commercial KET cream; the results showed that the combination of ME with HP-β-CD exhibited significantly synergistic effect on KET deposition within the skin (29.38 ± 1.79 μg/cm(2)) and a slightly synergistic effect on KET penetration through the skin (11.3 μg/cm(2)/h). The enhancement of the combination on skin deposition was further visualized by confocal laser scanning microscope (CLSM). In vitro sensitivity against Candida parapsilosis test indicated that KET-CD-ME enhanced KET antifungal activity mainly owing to the solubilization of HP-β-CD on KET in the ternary system. Moreover, the interactions between HP-β-CD and KET in the ternary system were elucidated through microScale thermophoresis (MST) and 2D (1)H NMR spectroscopy. The profiles from MST confirmed the host-guest interactions of HP-β-CD with KET in the ternary system and a deep insight into the interactions between KET and HP-β-CD were obtained by means of 2D (1)H NMR spectroscopy. The results indicate that the ternary system of ME combination with HP-β-CD may be a promising approach for skin targeting delivery of KET.