Pharmacokinetics and distribution of schisandrol A and its major metabolites in rats

1.?Schizandrol A is an active component in schisandra, also the representative component for the identification of schisandra.

2.?A rapid resolution liquid chromatography coupled with quadruple–time–of–flight mass spectrometry (RRLC–QTOF/MS) was developed to investigate the pharmacokinetics of schizandrol A after its intragastric administration (50?mg/kg) in rats.

3.?Schizandrol A was rapidly absorbed (T _max = 2.07?h), with a longer duration (t _1/2 = 9.48?h) and larger apparent volume of distribution (Vz/F?=?111.81?l/kg) in rats. Schizandrol A can be detected in main organs and the order of its distribution was in the liver?>?kidney?>?heart?>?spleen?>?brain, particularly higher in the liver.

4.?Five schizandrol A metabolites were identified, including 2–demethyl–8(R)–hydroxyl–schizandrin, 3–demethyl–8(R)–hydroxyl–schizandrin, hydroxyl–schizandrin, demethoxy–schizandrin, 2, 3–demethyl–8(R)–hydroxyl–schizandrin, indicating that the hydroxylation and demethylation may be the major metabolic way of schizandrol A.

5.?This study defined the pharmacokinetic characteristics of schizandrol A in vivo, and the RRLC–QTOF/MS is more sensitive and less limited by conditions, and needs less samples, which may be a useful resource for the further research and development of schisandrol A.     

Interactions of organophosphorus pesticides with solute carrier (SLC) drug transporters

1.?Organophosphorus pesticides (OPs) are known to interact with human ATP-binding cassette drug efflux pumps. The present study was designed to determine whether they can also target activities of human solute carrier (SLC) drug transporters.

2.?The interactions of 13 OPs with SLC transporters involved in drug disposition, such as organic cation transporters (OCTs), multidrug and toxin extrusion proteins (MATEs), organic anion transporters (OATs) and organic anion transporting polypeptides (OATPs), were mainly investigated using transporter-overexpressing cell clones and fluorescent or radiolabeled reference substrates.

3.?With a cut-off value of at least 50% modulation of transporter activity by 100?µM OPs, OAT1 and MATE2-K were not impacted, whereas OATP1B1 and MATE1 were inhibited by two and three OPs, respectively. OAT3 activity was similarly blocked by three OPs, and was additionally stimulated by one OP. Five OPs cis-stimulated OATP2B1 activity. Both OCT1 and OCT2 were inhibited by the same eight OPs, including fenamiphos and phosmet, with IC₅₀ values however in the 3–30?µM range, likely not relevant to environmental exposure.

4.?These data demonstrated that various OPs inhibit SLC drug transporter activities, especially those of OCT1 and OCT2, but only when used at high concentrations not expected to occur in environmentally-exposed humans.     

Insulin-like growth factor-1 (IGF-1) poly (lactic-co-glycolic acid) (PLGA) microparticles – development,characterisation, and in vitro assessment of bioactivity for cardiac applications

Aim: The aim of this study was to evaluate the formulation of a synthetic IGF-1 (pIGF-1) in PLGA microparticles (MP).

Methods: Poly (lactic-co-glycolic acid) (PLGA) MPs loaded with pIGF-1 were prepared, characterised and evaluated using double emulsion solvent evaporation method.

Results: Spherical MPs showed an average particle size of 2?µm, encapsulation efficiency (EE) of 67% and 50% degradation over 15?days. With a view to enhancing retention in the myocardium, the MP formulation was encapsulated in a cross-linked hyaluronic acid hydrogel. pIGF-1 released from MPs and from MPs suspended in hyaluronic acid hydrogel remained bioactive, determined by a significant increase in cellular proliferation of c-kit⁺ cells.

Conclusion: This formulation has potential for loco-regional delivery to damaged myocardium to promote the survival of cardiomyocytes.     

Optimisation of the microencapsulation of lavender oil by spray drying

Background: Lavender oil consists of around 100 components and is susceptible to volatilisation and degradation reactions.

Aim: Microencapsulate lavender oil by spray drying using a biocompatible polymeric blend of gum acacia and maltodextrin to protect the oil components. Effect of total polymer content, oil loading, gum acacia, and maltodextrin proportions on the size, yield, loading, and encapsulation efficiency of the microparticles was investigated.

Methods: Morphology and oil localisation within microparticles were assessed by confocal laser scanning electron microscope. Structural preservation and compatibility were assessed using Fourier transform infra-red spectroscopy, differential scanning calorimetry, and gas chromatography–mass spectrometry.

Results: Lavender microparticles of size 12.42?±?1.79?µm prepared at 30 w/w% polymer concentration, 16.67 w/w% oil loading, and 25w/w% gum acacia showed maximum oil protection at high loading (12?mg w/w%), and encapsulation efficiency (77.89 w/w%).

Conclusion: Lavender oil was successfully microencapsulated into stable microparticles by spray drying using gum acacia/maltodextrin polymeric blend.     

Utility of food pellets containing 1-aminobenzotriazole for longer term in vivo inhibition of cytochrome P450 in mice

1. The utility of 1-aminobenzotriazole (ABT), incorporated in food, has been investigated as an approach for longer term inhibition of cytochrome P450 (P450) enzymes in mice.

2. In rats, ABT inhibits gastric emptying, to investigate this potential limitation in mice we examined the effect of ABT administration on the oral absorption of NVS-CRF38. Two hour prior oral treatment with 100?mg/kg ABT inhibited the oral absorption of NVS-CRF38, T_max was 4?hours for ABT-treated mice compared to 0.5?hours in the control group.

3. A marked inhibition of hepatic P450 activity was observed in mice fed with ABT containing food pellets for 1?month. P450 activity, as measured by the oral clearance of antipyrine, was inhibited on day 3 (88% of control), week 2 (83% of control) and week 4 (80% of control).

4. T_max values for antipyrine were comparable between ABT-treated mice and the control group, alleviating concerns about impaired gastric function.

5. Inclusion of ABT in food provides a minimally invasive and convenient approach to achieve longer term inhibition of P450 activity in mice. This model has the potential to enable pharmacological proof-of-concept studies for research compounds which are extensively metabolised by P450 enzymes.     

Substrate-dependent effects of molecular-targeted anticancer agents on activity of organic anion transporting polypeptide 1B1

1. Organic anion-transporting polypeptide 1B1 (OATP1B1) plays an important role in the hepatic uptake of a broad range of substrate drugs. In vitro experiments show that molecular-targeted agents do not always have similar effects on OATP1B1 activity.

2. The purpose of this study was to clarify whether the effects of molecular-targeted agents on OATP1B1 are substrate-dependent. We used OATP1B1-transfected cells to compare the effects of molecular-targeted agents on OATP1B1-mediated uptake of fluorescein (FL), 2′,7′-dichlorofluorescein (DCF), atorvastatin, SN-38 and valsartan.

3. Cabozantinib, cediranib, neratinib, pazopanib, regorafenib, sorafenib and tivantinib did not affect or only slightly affected OATP1B1-mediated substrate uptake. Nilotinib and lenvatinib moderately and strongly inhibited OATP1B1-mediated substrate uptake, respectively. In contrast, afatinib stimulated OATP1B1-mediated uptake of FL and SN-38, ceritinib stimulated that of valsartan, and nintedanib stimulated that of FL and valsartan. In addition, the effects of afatinib, ceritinib and nintedanib on OATP1B1 activity differed markedly depending on the type of substrate. Afatinib, ceritinib and nintedanib had a substrate-dependent effect on OATP1B1 activity.

4. We conclude that the evaluation of OATP1B1 activity using only a single probe substrate for some molecular-targeted agents may lead to a faulty understanding of their mechanisms of drug interactions.     

Metabolic disposition of WTX101 (bis-choline tetrathiomolybdate) in a rat model of Wilson disease

1. WTX101 (bis-choline tetrathiomolybdate) is an investigational copper (Cu)-protein-binding agent developed for the treatment of Wilson disease (WD), a rare genetic disorder caused by mutations in the ATP7B Cu-transporter and resulting in toxic Cu accumulation.

2. Mass balance of a single intravenous WTX101 dose, measured as molybdenum (Mo), was assessed over 168?h in control (Long Evans Agouti [LEA]) and Long-Evans Cinnamon (LEC) rats, a WD model.

3. In LEC rats, Mo was partially excreted (up to 45%); 29% by renal clearance, and faecal clearance, still ongoing at 168?h, accounted for 16%. In contrast, in LEA rats, Mo was almost fully excreted (～87%); 79% was renally cleared with only 7% faecal excretion.

4. In LEC rats, the proportion of faecal to renal Mo excretion was enhanced (4:6) compared to controls (1:9).

5. Substantially more Mo was found in LEC liver and kidney compared with LEA tissues, in line with tissue Cu distribution.

6. These findings are consistent with the WTX101 mechanism of action: in the WD model, excess Cu is removed from hepatic metallothionein and retained within the stable tetrathiomolybdate-Cu-albumin tripartite complex, preventing tetrathiomolybdate degradation and resulting in less urinary elimination and greater faecal excretion than in controls.     

Characterisation of peppermint (Mentha piperita L.) essential oil encapsulates

Aim: The aim was to choose the optimal encapsulation system and to incorporate encapsulates loaded with essential oil into the ice cream as a model food product.

Methods: Ca-alginate beads were produced by electrostatic extrusion process. Gelatine/alginate coacervates were processed with coacervation. Carnauba wax microparticles were produced using melt dispersion process. Morphological properties, chemical, and thermal stabilities of encapsulates were tested by SEM, FTIR spectral, and thermogravimetric analysis.

Results: Alginate provided sufficient emulsion stability over 1?h. Ca-alginate showed higher encapsulation efficiency (EE) (98.4?±?4.3%) compared to carnauba wax (94.2?±?7.8%) and gelatine/alginate coacervates (13.2?±?1.2%). The presence of essential oil in all three types of encapsulates confirmed with FTIR. The encapsulation process ensured controlled release and thermal stability of the oil.

Conclusions: Ca-alginate matrix as the most suitable for peppermint essential oil encapsulation. The sensory analysis showed that ice cream incorporating encapsulates is a promising system for the consumption of health beneficial peppermint essential oil.     

Direct and quantitative evaluation of the major human CYP contribution (fmCYP) to drug clearance using the in vitro Silensomes™ model

1.?We have applied the concept of using MBIs to produce CYP-Silensomes to quantify the contribution of the major CYPs to drug metabolism (fmCYP).

2.?The target CYPs were extensively and selectivity inhibited by the selected MBIs, while non-target CYPs were inhibited by less than 20% of the homologous control activities. Only CYP2D6-Silensomes exhibited a CYP2B6 inhibition that could be easily and efficiently encountered by subtracting the fm_CYP2B6 measured using CYP2B6-Silensomes to adjust the fm_CYP2D6.

3.?To validate the use of a panel of 6 CYP-Silensomes, we showed that the fmCYP values of mono- and multi-CYP metabolised drugs were well predicted, with 70% within?±?15% accuracy. Moreover, the correlation with observed fmCYP values was higher than that for rhCYPs, which were run in parallel using the same drugs (<45% within ±15% accuracy). Moreover, the choice of the RAF substrate in rhCYP predictions was shown to affect the accuracy of the fmCYP measurement.

4.?These results support the use of CYP1A2-, CYP2B6-, CYP2C8-, CYP2C9-, CYP2D6 and CYP3A4-Silensomes to accurately predict fmCYP values during the in vitro enzyme phenotyping assays in early, as well as in development, phases of drug development.     

Greater occipital and supraorbital nerve blockade for the preventive treatment of migraine: a single-blind,randomized, placebo-controlled study

Objective: Nerve injections have been used for the acute and preventive treatment of migraine in recent decades. Most of these injections focused on greater occipital nerve (GON) blockade. However, few studies were placebo controlled, and only a few of them investigated GON and supraorbital nerve (SON) blockade together. This study aimed to evaluate the efficacy of GON and SON blockade with local anesthetics for the preventive treatment of migraine without aura.

Methods: Eighty-seven patients diagnosed with migraine without aura were included in the study. Patients were divided randomly. One group was injected with 1% lidocaine, the other group was injected with 0.9% saline. GON and SON injections were done bilaterally. The injections were repeated weekly for 3 weeks. Patients were followed up for 2 months to assess clinical response.

Results: Seventy-one patients completed the study. After 2 months, the number of headache days decreased significantly from 12.8?±?10.9 to 5.3?±?7.4, and VAS decreased from 8.3?±?1.0 to 5.5?±?1.9 in the blockade group. The number of headache days decreased from 12.4?±?10.3 to 7.5?±?7.2 and VAS decreased from 8.2?±?1.1 to 7.4?±?1.3 in the placebo group. Response was seen in 65.1% of the patients in the blockade group (65.4% for episodic migraine, 64.7% for chronic migraine) and 28.6% of the patients in the placebo group. The difference was significant.

Conclusions: The results suggest that GON and SON blockade with lidocaine was more effective than the placebo in the prophylactic treatment of both episodic and chronic migraine.     

Non-clinical pharmacokinetic profiles of rovatirelin,an orally available thyrotropin-releasing hormone analogue

1. The non-clinical pharmacokinetic profiles of rovatirelin, a novel thyrotropin-releasing hormone (TRH) analogue, were investigated in vivo and in vitro.

2. Rovatirelin orally administered to rats and dogs was rapidly absorbed and bioavailability was estimated to be 7.3 and 41.3%, respectively. The extent of plasma protein binding of rovatirelin in rats, dogs, and humans was low in all species (～15%). The permeability of rovatirelin from blood to brain (permeability-surface area) ranged from 1.04?±?0.14 to 1.29?±?0.28?μL/min/g in rats, and rovatirelin was stable in rat plasma and brain homogenates.

3. The metabolite pattern was qualitatively similar in vitro and in vivo. In animals, rovatirelin aminopentanoic acid (rovatirelin-acid), rovatirelin aminopentanone (rovatirelin-ketone), rovatirelin pyrrolidine (4S)-hydroxy (rovatirelin-OH), (thiazoylalanyl)methylpyrrolidine (TAMP), 3-(4-thiazoyl)-l-alanine (TA), and unknown metabolites were observed. In human hepatocytes, TAMP was mainly formed and no unique human metabolite was observed.

4. The radioactivity from administered [¹⁴C]rovatirelin was predominantly excreted in faeces in rats and dogs, and almost all radioactivity was recovered 168?h after administration. Absorption, brain penetration, and stability of rovatirelin in the brain were greater than for taltirelin.

5. Thus, orally administered rovatirelin is a potentially improved treatment for spinocerebellar degeneration compared with taltirelin.     

Comparison of a twice daily injection of insulin aspart 50 with insulin aspart 30 in patients with poorly controlled type 2 diabetes

Objective: To compare the efficacy and safety of a twice daily injection of insulin aspart (BIAsp) 30 and BIAsp50 in patients with type 2 diabetes mellitus (T2DM) poorly controlled with oral hypoglycemic agents (OHAs).

Methods: In this 12 week prospective, randomized, parallel trial, a total of 80 T2DM patients, 59?±?10?years old with a disease duration of 9.3?±?6.6?years and HbA1c >7% despite large doses of metformin and sulfonylurea administration, were randomized to receive BIAsp30 (n?=?40) or BIAsp50 (n?=?40). The primary endpoint was a change in HbA1c at week 12.

Results: The changes in HbA1c from baseline were ?2.5%?±?1.0% in the BIAsp50 group and ?2.5%?±?1.2% in the BIAsp30 group (p?=?.897). No difference was observed in the rate of HbA1c target achievement (<7.0%) between BIAsp50 (42.5%) and BIAsp30 (32.5%) (p?=?.495). The change in fasting plasma glucose (FPG) in the BIAsp50 group was lower than that in the BIAsp30 group (p?<?.001), while the change in two-hour postprandial blood glucose (2hPBG) was higher and blood glucose excursion was lower in the BIAsp50 group than that in the BIAsp30 group (p?<?.001, p?<?.001). A significant improvement in HbA1c was observed with BIAsp50 in subgroups with baseline blood glucose excursion >7.8?mmol/L or 2hPBG >17.6?mmol/L compared with BIAsp30. There were no differences in hypoglycemia or body weight between groups.

Conclusions: Compared with BIAsp30, BIAsp50 showed greater efficacy in patients with baseline BG excursion >7.8?mmol/L or 2hPBG >17.6?mmol/L as well as good safety for hypoglycemia.

Clinical trial registration: ChiCTR-IIR-16008958.     

Cytochrome P450 2A6 and other human P450 enzymes in the oxidation of flavone and flavanone

1.?We previously reported that flavone and flavanone interact spectrally with cytochrome P450 (P450 or CYP) 2A6 and 2A13 and other human P450s and inhibit catalytic activities of these P450 enzymes. In this study, we studied abilities of CYP1A1, 1A2, 1B1, 2A6, 2A13, 2C9 and 3A4 to oxidize flavone and flavanone.

2.?Human P450s oxidized flavone to 6- and 5-hydroxylated flavones, seven uncharacterized mono-hydroxylated flavones, and five di-hydroxylated flavones. CYP2A6 was most active in forming 6-hydroxy- and 5-hydroxyflavones and several mono- and di-hydroxylated products.

3.?CYP2A6 was also very active in catalyzing flavanone to form 2′- and 6-hydroxyflavanones, the major products, at turnover rates of 4.8?min^?1 and 1.3?min^?1, respectively. Other flavanone metabolites were 4′-, 3′- and 7-hydroxyflavanone, three uncharacterized mono-hydroxylated flavanones and five mono-hydroxylated flavones, including 6-hydroxyflavone. CYP2A6 catalyzed flavanone to produce flavone at a turnover rate of 0.72?min^?1 that was ～3-fold higher than that catalyzed by CYP2A13 (0.29?min^?1).

4.?These results indicate that CYP2A6 and other human P450s have important roles in metabolizing flavone and flavanone, two unsubstituted flavonoids, present in dietary foods. Chemical mechanisms of P450-catalyzed desaturation of flavanone to form flavone are discussed.     

In vitro analysis of itraconazole cis-diastereoisomers inhibition of nine cytochrome P450 enzymes: stereoselective inhibition of CYP3A

1. Itraconazole (ITZ), an antifungal azole derivate is a chiral drug that consists of four cis-diastereoisomers ((+)-2R,4S,2′R-ITZ-A; (+)-2R,4S,2′S-ITZ-B; (–)-2S,4R,2′S-ITZ-C and (–)-2S,4R,2′R-ITZ-D) which may differ in their pharmacokinetics and pharmacodynamics.

2. As ITZ is known as a CYP3A4 inhibitor causing severe drug–drug interaction, the inhibitory potencies of its individual optical isomers towards nine drug-metabolising cytochrome P450 (including CYP3A, CYP1A2, CYP2A6, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6 and CYP2E1), were investigated.

3. All ITZ diastereoisomers dose-dependently inhibited CYP3A activity in both used assays, midazolam and testosterone hydroxylation. The K_i values were assessed: for testosterone ITZ-A/0.085 µM; ITZ-B/0.91 µM, ITZ-C/0.20?µM and ITZ-D/0.022 µM; for midazolam ITZ-A/0.44 µM; ITZ-B/0.48 µM, ITZ-C/1.56 µM and ITZ-D/3.48 µM. The enzyme activity of CYP2C19 was moderately inhibited (IC50 30–53 µM), but in this case without large differences between the individual optical isomers.

4. The significant differences between diastereoisomers were presented. Antifungal potency of ITZ stereoisomers also differs so the potential enantiopure preparations of ITZ was not of interest.     

Application of disaccharides alone and in combination,for the improvement of stability and particle properties of spray-freeze dried IgG

Purpose: Spray-freeze drying (SFD) is a recently applied method to develop pharmaceutical powders. This study aimed to analyze the competence of Trehalose, Mannitol, Lactose, and Sorbitol instability and aerosolization of Immunoglobulin G (IgG) via SFD.

Methods: Induced soluble aggregates were quantified at 0 and 3?months, and 45?°C using size-exclusion chromatography. Conformation and thermogravimetric assessments were done by Fourier transform infrared spectroscopy and differential scanning calorimetry. Laser light scattering was performed to determine the particle sizes. Aerodynamic features were characterized by twin stage impinger and scanning electron microscopy.

Results: Although sugars/polyols preferably stabilized IgG following the process, storage stabilization was achieved in Trehalose, Trehalose-Lactose, Lactose, and Trehalose-Mannitol-based powders with soluble aggregates <5%. The conformation of antibody was preserved with β sheet content from 66.28% to 76.37%. Particle sizes ranged from 5.23 to 8.12?µm. Mannitol exhibited the best aerodynamic behavior, fine particle fraction (FPF: 70%) but high degree of protein aggregation during storage.

Conclusions: SFD could favorably stabilize antibody using Trehalose and its combination with Lactose and Mannitol, and also, Lactose alone. Sorbitol disturbed IgG powder recovery. Incorporation of other types of excipient is required for efficient respiratory delivery of IgG molecules.     

An evaluation of peripapillar choroidal thickness in patients receiving systemic isotretinoin treatment

Purpose: Oral isotretinoin (13-cis retinoic acid, 13-cis RA) was approved for severe acne treatment by the FDA in 1982. The ocular side effects associated with oral isotretinoin use are mostly dose-dependent. Numerous ocular pathologies affect peripapillary choroidal layer primarily or indirectly.

Objective: Evaluation of the peripapillary choroidal layer in the patients receiving oral isotretinoin therapy may aid in explaining the pathophysiology of ocular side effects.

Methods: In this study, peripapillary choroidal thickness was assessed in the patients receiving oral isotretinoin treatment via optical coherent tomography technique.

Results: Significant difference was found in the superotemporal and temporal areas.

Conclusion: Oral isotretinoin treatment may affect the thickness of the peripapillary choroidal layer.     

Functional characterization of 21 CYP3A4 variants on amiodarone metabolism in vitro

1. Cytochrome P450 3A4 (CYP3A4) is an important member of the cytochrome P450 enzyme superfamily, with 33 allelic variants reported previously. Genetic polymorphisms of CYP3A4 can produce a significant effect on the efficacy and safety of some drugs, so the purpose of this study was to clarify the catalytic characteristics of 22 CYP3A4 allelic isoforms, including 6 novel variants in Han Chinese population, on the oxidative metabolism of amiodarone in vitro.

2. Wild-type CYP3A4*1 and other variants expressed by insect cells system were incubated respectively with 10–500?μM substrate for 40?min at 37?°C and terminated at ?80?°C immediately. Then these samples were treated as required and detected with ultra-performance liquid chromatography-tandem mass spectrometry used to analyze its major metabolite desethylamiodarone.

3. Among the 21 CYP3A4 variants, compared with the wild-type, the intrinsic clearance values (V_max/K_m) of two variants were apparently decreased (11.07 and 2.67% relative clearance) while twelve variants revealed markedly increased values (155.20～435.96%), and the remaining of seven variants exhibited no significant changes in enzyme activity.

4. This is the first time report describing all these infrequent alleles for amiodarone metabolism, which can provide fundamental data for further clinical studies on CYP3A4 alleles.     

Pre-formulation investigations for establishing a protocol for treosulfan handling and activation

Introduction: Treosulfan is an alkylating agent that is used for the treatment of ovarian cancer and for conditioning prior to stem cell transplantation. It is a prodrug that is activated non-enzymatically to two active epoxides.

Objectives: To optimize a protocol for both in vivo samples handling and in vitro drug preparation. Treosulfan stability was tested in biological fluids at different conditions as well as for its cytotoxicity on cell lines.

Results: Plasma samples can be safely frozen for a short period up to 8?h, however; for longer periods, samples should be acidified. Urine samples and cell culture media can be safely frozen regardless their pH. For in vitro investigations, incubation of treosulfan at 37?°C for 24?h activated 100% of the drug. Whole blood acidification should be avoided for the risk of hemolysis. Finally; treosulfan cytotoxicity on HL-60 cells has increased following pre-incubation for 24?h at 37?°C compared to K562 cell line.

Conclusion: The stability profiling of treosulfan provided a valuable reference for handling of biological samples for both in vivo and in vitro studies. These results can be utilized for further investigations concerning the drug kinetics and dynamics in addition to the development of new pharmaceutical formulations.     

The effect of complexation with cyclodextrins on the antioxidant and antimicrobial activity of ellagic acid

Purpose: The aim of the paper was to develop the simple procedures for preparation of inclusion complexes of ellagic acid (EA) with cyclodextrins (CDs) and to investigate their antioxidant and antimicrobial activity.

Methods: The structural characterization was carried out using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and nuclear magnetic resonance (NMR) methods. The phase solubility technique was used to investigate the interactions between ‘host’ and ‘guest’ molecules and to estimate the molar ratio between them. The antioxidant and antimicrobial activity of EA and inclusion complexes were determined.

Results: The apparent stability constants were found to be 117?dm³ mol^?1 for the complex with β-CD and 161?dm³ mol^?1 for the complex with (2-hydroxypropyl)-β-cyclodextrin (HP-β-CD). The results of phase-solubility studies showed that EA formed the inclusion complexes with CDs in the molar ratio of 1:1. The calculated half-maximal inhibitory concentration was 41.18?μg cm^?3 for butyl hydroxy toluene, 1.96?μg cm^?3 for EA, 0.88?μg cm^?3 for inclusion complex with HP-β-CD, and 1.27?μg cm^?3 for inclusion complex with β-CD.

Conclusion: The stability constants indicated the rapid release of EA from the inclusion complexes in the aqueous medium at 25?°C. The antioxidant activity of EA was increased, while the antimicrobial activity was preserved after complexation with CDs.