Eco-friendly electrochemical assay of oxytetracycline and flunixin in their veterinary injections and spiked milk samples.

Two solid-contact electrochemical sensors were developed for detection of each of oxytetracycline HCl (OXY), and the co-formulated non-steroidal anti-inflammatory drug flunixin meglumine (FLU) in veterinary formulations and animal-derived food products. The designed sensors were based on a glassy carbon electrode as the substrate material and high molecular weight polyvinyl chloride (PVC) polymeric ion-sensing membranes doped with multiwalled carbon nanotubes (MWCNTs) to improve the potential stability and minimize signal drift. For determination of OXY, the sensing membrane was modified with potassium tetrakis (4-chlorophenyl) borate (K-TCPB), which was employed as a cation exchanger, and 2-hydroxypropyl-ß-cyclodextrin (HP-ßCD), which was used as an ionophore. A linear response within a concentration range of 1 × 10- 6-1 × 10- 2 M with a slope of 59.47 mV/decade over a pH range of 1-5 was recorded. For the first time, two potentiometric electrodes were developed for determination of FLU, where the sensing membrane was modified with tetra dodecyl ammonium chloride (TDDAC) as an anion exchanger. A linear response within a concentration range of 1 × 10- 5-1 × 10- 2 M and a slope of -58.21 mV/decade over a pH range of 6-11 was observed. The suggested sensors were utilized for the selective determination of each drug in pure powder form, in veterinary formulations, and in spiked milk samples, with mean recoveries ranging from 98.50 to 102.10, and without any observed interference. The results acquired by the proposed sensors were statistically analyzed and compared with those acquired by the official methods, and the results showed no significant difference.

Differently increased volumes of multiple brain areas in Npc1 mutant mice following various drug treatments.

Background: Niemann-Pick disease type C1 (NPC1, MIM 257220) is a heritable lysosomal storage disease characterized by a progressive neurological degeneration that causes disability and premature death. A murine model of Npc1-/- displays a rapidly progressing form of Npc1 disease, which is characterized by weight loss, ataxia, and increased cholesterol storage. Npc1-/- mice receiving a combined therapy (COMBI) of miglustat (MIGLU), the neurosteroid allopregnanolone (ALLO) and the cyclic oligosaccharide 2-hydroxypropyl-ß-cyclodextrin (HPßCD) showed prevention of Purkinje cell loss, improved motor function and reduced intracellular lipid storage. Although therapy of Npc1-/- mice with COMBI, MIGLU or HPßCD resulted in the prevention of body weight loss, reduced total brain weight was not positively influenced. Methods: In order to evaluate alterations of different brain areas caused by pharmacotherapy, fresh volumes (volumes calculated from the volumes determined from paraffin embedded brain slices) of various brain structures in sham- and drug-treated wild type and mutant mice were measured using stereological methods. Results: In the wild type mice, the volumes of investigated brain areas were not significantly altered by either therapy. Compared with the respective wild types, fresh volumes of specific brain areas, which were significantly reduced in sham-treated Npc1-/- mice, partly increased after the pharmacotherapies in all treatment strategies; most pronounced differences were found in the CA1 area of the hippocampus and in olfactory structures. Discussion: Volumes of brain areas of Npc1-/- mice were not specifically changed in terms of functionality after administering COMBI, MIGLU, or HPßCD. Measurements of fresh volumes of brain areas in Npc1-/- mice could monitor region-specific changes and response to drug treatment that correlated, in part, with behavioral improvements in this mouse model.

Impact of 2-hydroxypropyl-ß-cyclodextrin inclusion complex formation on dopamine receptor-ligand interaction - A case study.

The octanol-water distribution coefficient (logP), used as a measure of lipophilicity, plays a major role in the drug design and discovery processes. While average logP values remain unchanged in approved oral drugs since 1983, current medicinal chemistry trends towards increasingly lipophilic compounds that require adapted analytical workflows and drug delivery systems. Solubility enhancers like cyclodextrins (CDs), especially 2-hydroxypropyl-ß-CD (2-HP-ß-CD), have been studied in vitro and in vivo investigating their ADMET (adsorption, distribution, metabolism, excretion and toxicity)-related properties. However, data is scarce regarding the applicability of CD inclusion complexes (ICs) in vitro compared to pure compounds. In this study, dopamine receptor (DR) ligands were used as a case study, utilizing a combined in silico/in vitro workflow. Media-dependent solubility and IC stoichiometry were investigated using HPLC. NMR was used to observe IC formation-caused chemical shift deviations while in silico approaches utilizing basin hopping global minimization were used to propose putative IC binding modes. A cell-based in vitro homogeneous time-resolved fluorescence (HTRF) assay was used to quantify ligand binding affinity at the DR subtype 2 (D2R). While all ligands showed increased solubility using 2-HP-ß-CD, they differed regarding IC stoichiometry and receptor binding affinity. This case study shows that IC-formation was ligand-dependent and sometimes altering in vitro binding. Therefore, IC complex formation can't be recommended as a general means of improving compound solubility for in vitro studies as they may alter ligand binding.

Supranuclear Palsy as an Initial Presentation of the Adult-Onset Niemann-Pick Type C.

(1) Background: Niemann-Pick type C1 (NP-C1) is a lysosomal storage disorder that results in the defective trafficking of cholesterol and other cellular lipids in the endosomal-lysosomal pathway. This rare autosomal recessive disorder presents in three forms based on the age of onset. The adult form presents in patients greater than 15 years of age but is rarely seen after the age of 30. Common symptoms of the late adult-onset category of NP-C1 include progressive cognitive impairment and ataxia, with psychiatric and movement disorders presenting less frequently than in other forms of NP-C1. Dystonic movement disorders present most frequently, along with chorea, myoclonus, and parkinsonism. Herein, we present a rare case of NP-C1, diagnosed at age 35 with an initial symptom of supranuclear palsy. The goal of the presented case is to highlight the importance of the neurological examination and an inclusive differential diagnosis in patients with new-onset supranuclear palsy. (2) Methods: A single case report. (3) Results: A 46-year-old male with a past medical history of NP-C1 was admitted to the hospital for respiratory distress. He was noted to have a supranuclear gaze palsy with partially preserved voluntary saccades to the right. His mother revealed that he first had difficulty moving his eyes at the age of 34. After multiple consultations and genetic testing one year later, he was diagnosed with NP-C1. (4) Conclusions: Because NP-C1 affects many regions of the brain responsible for eye movements, neurological eye assessments can be a useful tool in diagnoses. Furthermore, eye movement abnormalities may be the initial presenting symptom of NP-C1, predisposing patients to misdiagnosis with progressive supranuclear palsy and other conditions that may mimic early-stage NP-C1. Definitive diagnosis is achieved through genetic testing. Filipin staining test was the gold standard in the past. The NP-C Suspicion Index was developed to assist in diagnoses, but its efficacy is unclear with late adult-onset NP-C1. Although no cure exists, early identification can facilitate an improved symptom management course for patients. Miglustat, a glucosylceramide synthase (GCS) inhibitor, is the approved therapy in Europe specific to NP-C1 for slowing and preventing the neurological manifestations of NP-C1. Delays between symptom onset and treatment initiation are likely to result in poorer outcomes and a progression of neurological symptoms. High doses may present tolerance concerns, especially in cases of delayed treatment and advanced neurological deficit.

Mechanistic insight of α-mangostin encapsulation in 2-hydroxypropyl-ß-cyclodextrin for solubility enhancement.

α-Mangostin is the most abundant compound contained in the mangostin (Garcinia mangostana L.) plant which have been developed and proven to have many promising pharmacological effects. However, the low water solubility of α-mangostin causes limitations in its development in clinical purpose. To increase the solubility of a compound, a method currently being developed is to make drug inclusion complexes using cyclodextrins. This research aimed to use in silico techniques namely molecular docking study and molecular dynamics simulation to explore the molecular mechanism and stability of the encapsulation of α-mangostin using cyclodextrins. Two types of cyclodextrins were used including ß-cyclodextrin and 2-hydroxypropyl-ß-cyclodextrin docked against α-mangostin. From the molecular docking results, it shows that the α-mangostin complex with 2-hydroxypropyl-ß-cyclodextrin provides the lowest binding energy value of -7.99 Kcal/mol compared to ß-cyclodextrin value of -6.14 Kcal/mol. The α-mangostin complex with 2-hydroxypropyl-ß-cyclodextrin also showed good stability based on molecular dynamics simulation during 100 ns. From molecular motion, RDF, Rg, SASA, density, total energy analyzes, this complex shows increased solubility in water and provided good stability. This indicates that the encapsulation of α-mangostin with 2-hydroxypropyl-ß-cyclodextrin can increase the solubility of the α-mangostin.Communicated by Ramaswamy H. Sarma.

Folate-Appended Hydroxypropyl-ß-Cyclodextrin Induces Autophagic Cell Death in Acute Myeloid Leukemia Cells.

Acute myeloid leukemia (AML) is a heterogenous myeloid neoplasm that remains challenging to treat. Because intensive conventional chemotherapy reduces survival rates in elderly patients, drugs with lower toxicity and fewer side effects are needed urgently. 2-Hydroxypropyl-ß-cyclodextrin (HP-ß-CyD) is used clinically as a pharmaceutical excipient for poorly water-soluble drugs. Previously, we showed that HP-ß-CyD exerts antitumor activity by disrupting cholesterol homeostasis. Recently, we developed folate-conjugated HP-ß-CyD (FA-HP-ß-CyD) and demonstrated its potential as a new antitumor agent that induces not only apoptosis, but also autophagic cell death; however, we do not know whether FA-HP-ß-CyD exerts these effects against AML. Here, we investigated the effects of FA-HP-ß-CyD on folate receptor (FR)-expressing AML cells. We found that the cytotoxic activity of FA-HP-ß-CyD against AML cells was stronger than that of HP-ß-CyD. Also, FA-HP-CyD induced the formation of autophagosomes in AML cell lines. FA-HP-ß-CyD increased the inhibitory effects of cytarabine and a BCL-2-selective inhibitor, Venetoclax, which are commonly used treat elderly AML patients. Notably, FA-HP-ß-CyD suppressed the proliferation of AML cells in BALB/c nude recombinase-activating gene-2 (Rag-2)/Janus kinase 3 (Jak3) double-deficient mice with AML. These results suggest that FA-HP-ß-CyD acts as a potent anticancer agent for AML chemotherapy by regulating autophagy.

Change in the Kinetic Regime of Aggregation of Yeast Alcohol Dehydrogenase in the Presence of 2-Hydroxypropyl-ß-cyclodextrin.

Chemical chaperones are low-molecular-weight compounds that suppress protein aggregation. They can influence different stages of the aggregation process-the stage of protein denaturation, the nucleation stage and the stage of aggregate growth-and this may lead to a change in the aggregation kinetic regime. Here, the possibility of changing the kinetic regime in the presence of a chemical chaperone 2-hydroxypropyl-ß-cyclodextrin (2-HP-ß-CD) was investigated for a test system based on the thermally induced aggregation of yeast alcohol dehydrogenase (yADH) at 56 °C. According to differential scanning calorimetry data, 2-HP-ß-CD did not affect the stage of the protein molecule unfolding. Dynamic light scattering data indicated changes in the aggregation kinetics of yADH during the nucleation and aggregate growth stages in the presence of the chaperone. The analysis of kinetic curves showed that the order of aggregation with respect to protein (nc), calculated for the stage of aggregate growth, changed from nc = 1 to nc = 2 with the addition of 100 mM 2-HP-ß-CD. The mechanism of 2-HP-ß-CD action on the yADH thermal aggregation leading to a change in its kinetic regime of aggregation is discussed.

Deep Eutectic Solvents Based on L-Arginine and 2-Hydroxypropyl-ß-Cyclodextrin for Drug Carrier and Penetration Enhancement.

By selecting L-arginine as the hydrogen bond acceptor (HBA) and 2-hydroxypropyl-ß-cyclodextrin (2HPßCD) as the hydrogen bond donor (HBD), deep eutectic solvents (DESs) with various water content were prepared at the 4:1 mass ratio of L-arginine to 2HPßCD with 40 to 60% of water, and were studied for its application in transdermal drug delivery system (TDDS). The hydrogen bond networks and internal chemistry structures of the DESs were measured by attenuated total reflection Fourier transform infrared (ATR-FTIR) and 1H-nuclear magnetic resonance spectroscopy (1H-NMR), which demonstrated the successful synthesis of DESs. The viscosity of DES was decreased from 10,324.9 to 3219.6 mPa s, while glass transition temperature (Tg) of the DESs was increased from - 60.8 to - 51.4 °C, as the added water was increased from 45 to 60%. The solubility of ibuprofen, norfloxacin, and nateglinide in DES with 45% of water were increased by 79.3, 44.1, and 3.2 times higher than that in water, respectively. The vitro study of transdermal absorption of lidocaine in DESs showed that the cumulative amounts of lidocaine reached 252.4 µg/cm2, 226.1 µg/cm2, and 286.1 µg/cm2 at 8 h for DESs with 45%, 50%, and 60% of water, respectively. The permeation mechanism of DES with lower content of water (45%) was mainly by changing the fluidization of lipids, while changing the secondary structure of keratin in stratum corneum (SC) at higher water content (50% and 60%). These nonirritant and viscous fluid like DESs with good drug solubility and permeation enhancing effects have broad application prospect in the field of drug solubilization and transdermal drug delivery system.

Effect of Chemical Chaperones on the Stability of Proteins during Heat- or Freeze-Thaw Stress.

The importance of studying the structural stability of proteins is determined by the structure-function relationship. Protein stability is influenced by many factors among which are freeze-thaw and thermal stresses. The effect of trehalose, betaine, sorbitol and 2-hydroxypropyl-ß-cyclodextrin (HPCD) on the stability and aggregation of bovine liver glutamate dehydrogenase (GDH) upon heating at 50 °C or freeze-thawing was studied by dynamic light scattering, differential scanning calorimetry, analytical ultracentrifugation and circular dichroism spectroscopy. A freeze-thaw cycle resulted in the complete loss of the secondary and tertiary structure, and aggregation of GDH. All the cosolutes suppressed freeze-thaw- and heat-induced aggregation of GDH and increased the protein thermal stability. The effective concentrations of the cosolutes during freeze-thawing were lower than during heating. Sorbitol exhibited the highest anti-aggregation activity under freeze-thaw stress, whereas the most effective agents stabilizing the tertiary structure of GDH were HPCD and betaine. HPCD and trehalose were the most effective agents suppressing GDH thermal aggregation. All the chemical chaperones stabilized various soluble oligomeric forms of GDH against both types of stress. The data on GDH were compared with the effects of the same cosolutes on glycogen phosphorylase b during thermal and freeze-thaw-induced aggregation. This research can find further application in biotechnology and pharmaceutics.

2-Hydroxypropyl-ß-cyclodextrin (HPßCD) as a Potential Therapeutic Agent for Breast Cancer.

Cholesterol accumulation is documented in various malignancies including breast cancer. Consequently, depleting cholesterol in cancer cells can serve as a viable treatment strategy. We identified the potency of 2-hydroxypropyl-ß-cyclodextrin (HPßCD), a cholesterol-depletor in vitro against two breast cancer cell lines: MCF-7 (Oestrogen-receptor positive, ER+) and MDA-MB-231 (Triple negative breast cancer (TNBC)). The results were then compared against two non-cancerous cell lines using cytotoxic-, apoptosis-, and cholesterol-based assays. Treatment with HPßCD showed preferential and significant cytotoxic potential in cancer cells, inducing apoptosis in both cancer cell lines (p < 0.001). This was mediated due to significant depletion of cholesterol (p < 0.001). We further tested HPßCD in a MF-1 mice (n = 14) xenograft model and obtained 73.9%, 94% and 100% reduction in tumour size for late-, intermediate-, and early-stage TNBC, respectively. We also detected molecular-level perturbations in the expression patterns of several genes linked to breast cancer and cholesterol signalling pathways using RT2-PCR arrays and have identified SFRP1 as a direct binding partner to HPßCD through SPR drug interaction analysis. This work unravels mechanistic insights into HPßCD-induced cholesterol depletion, which leads to intrinsic apoptosis induction. Results from this study potentiate employing cholesterol depletion as a promising unconventional anticancer therapeutic strategy, which warrants future clinical investigations.

Molecular Mind Games: The Medicinal Action of Cyclodextrins in Neurodegenerative Diseases.

Cyclodextrins are often used as molecular carriers for small active ingredients in medicine. Recently, the intrinsic medicinal activity of some of these compounds has been under investigation, mainly related to their ability to interfere with cholesterol and, therefore, prevent and treat cholesterol-related diseases such as cardiovascular disease and neuronal diseases arising from altered cholesterol and lipid metabolism. One of the most promising compounds within the cyclodextrin family is 2-hydroxypropyl-ß-cyclodextrin (HPßCD), owing to its superior biocompatibility profile. This work presents the most recent advances in the research and clinical use of HPßCD against Niemann-Pick disease, a congenital condition involving cholesterol accumulation inside lysosomes in brain cells, Alzheimer's and Parkinson's. HPßCD plays a complex role in each of these ailments, going beyond the mere sequestering of cholesterol molecules and involving an overall regulation of protein expression that helps restore the normal functioning of the organism.

Pharmacokinetic studies of hyperoside-2-hydroxypropyl-ß-cyclodextrin inclusion complex and ameliorated DSS-induced colitis in mice.

An inclusion complex formation with cyclodextrin is a promising method to improve the bioavailability of water-insoluble drugs. The pharmacokinetic characteristics of Hyperoside-2-hydroxypropyl-ß-cyclodextrin inclusion complex in rats were evaluated. Compared with Hyperoside, the results showed that maximum plasma concentration and AUC0-t indexes of Hyperoside inclusion complex in rat plasma were increased, the value of half-life time was prolonged, and the value of apparent clearance was decreased, which proved that Hyperoside complexed with 2-hydroxypropyl-ß-cyclodextrin could improve its bioavailability and increase its blood concentration. Secondly, the therapeutic effect of Hyperoside before and after complexing was further compared through the dextran sodium sulfate-induced colitis in mice. The experimental results showed that under the same dose, the Hyperoside inclusion complex had a better therapeutic effect, which could significantly increase the body weight of mice, improve the disease activity index, alleviate colon shortening, improve pathological colon changes, and have a better protective effect on colitis mice. According to 16S rDNA sequencing analyses, Hyperoside-2-hydroxypropyl-ß-cyclodextrin may have an anti-inflammatory effect by increasing the abundance of beneficial bacteria (e.g. Firmicuria) and decreasing the proportion of harmful bacteria (e.g. Bacteroidetes) to balance the colon's microbiota.

Preparation and characterization of inclusion complex of Myristica fragrans Houtt. (nutmeg) essential oil with 2-hydroxypropyl-ß-cyclodextrin.

Nutmeg essential oil (NEO) is a natural condimentwith versatile biological activities. However, the application of NEO in food has several limitations due to its poor stability and low aqueous solubility. To overcome the shortcomings, this paper focused on the preparation of the inclusion complex (IC) of NEO with 2-hydroxypropyl-ß-cyclodextrin (HP-ß-CD) by the coprecipitation method. The optimal condition was inclusion temperature 36 ℃, time 247 min, stirring speed 520 r/min, and wall-core ratio 12:1, resulting in a recovery of 80.63%. The formation of IC was verified by various methods such as scanning electron microscopy, Fourier transform infrared spectroscopy and nuclear magnetic resonance. The improvement of thermal stability, antioxidant, and nitrite scavenging activities of NEO after encapsulation was proven. Moreover, the controlled release of NEO from IC can be implemented by regulating the temperature and relative humidity. Overall, NEO/HP-ß-CD IC has great application potential in food industries.

Overview of Prostaglandin E2 (PGE2)-Targeting Radiolabelled Imaging Probes from Preclinical Perspective: Lessons Learned and Road Ahead.

As malignancies still represent one of the major health concerns worldwide, early tumor identification is among the priorities of today's science. Given the strong association between cyclooxygenase-2 (COX-2)/prostaglandin E2 (PGE2), PGE2 receptors (EPs), and carcinogenesis, target-specific molecules directed towards the components of the COX2/PGE2/EP axis seem to be promising imaging probes in the diagnostics of PGE2pos. neoplasms and in the design of anti-cancer drugs. Featured with outstanding inclusion forming capability, ß-cyclodextrins (CDs) including randomly methylated ß-CD (RAMEB) were reported to complex with PGE2. Therefore, radiolabelled ß-CDs could be valuable vectors in the molecular imaging of PGE2-related tumorigenesis. In vivo preclinical small animal model systems applying positron emission tomography (PET) ensure a well-suited scenario for the assessment of PGE2-affine labelled CD derivatives. Previous translational studies dealt with the evaluation of the tumor-homing capability of Gallium-68 (68Ga) and Bismuth-205/206 (205/206Bi)-appended ß-CD compounds conjugated with chelator NODAGA or DOTAGA: [68Ga]Ga-NODAGA-2-hydroxypropyl-ß-cyclodextrin/HPBCD, [68Ga]Ga-NODAGA-RAMEB, [68Ga]Ga-DOTAGA-RAMEB, and [205/206Bi]Bi-DOTAGA-RAMEB in experimental tumors with different PGE2 expression. These imaging probes project the establishment of tailor-made PET diagnostics of PGE2pos. malignancies. In the present review, we provide a detailed overview of the in vivo investigations of radiolabelled PGE2-directed CDs, highlighting the importance of the integration of translational discoveries into routine clinical usage.

Strategies To Stabilize Dalbavancin in Aqueous Solutions; Section 3: The Effects of 2 Hydroxypropyl-ß-Cyclodextrin and Phosphate Buffer with and without Divalent Metal Ions.

PURPOSE: New formulations of the glycopeptide drug dalbavancin containing 2-hydroxpropyl-ß-cyclodextrin (2HPßCD) with or without divalent metal ions in phosphate buffer (pH 7.0) were tested to evaluate whether these excipients influence the aqueous solution stability of dalbavancin. METHOD: Recovery of dalbavancin from phosphate buffered solutions at pH 7.0 with different concentrations of 2HPßCD and a divalent metal ion (Ca2+, Mg2+, or Zn2+) was evaluated by RP-HPLC and HP-SEC after four weeks of storage at 5°C and 55°C. A long-term study of formulations with 2HPßCD and Mg2+ was carried out over six months at 5°C, 25°C, and 40°C using RP-HPLC. RESULTS: Dalbavancin solutions with either 5.5 mM or 55 mM 2HPßCD were significantly more stable with Mg2+ than with the other divalent metal ions, both at 55°C for four weeks and at 40°C for six months. Dalbavancin was found to be more stable in aqueous solutions at a concentration of 1 mg/mL than at 20 mg/mL with 2HPßCD and Mg2+ at 40°C for six months. CONCLUSION: The results suggest that 2HPßCD forms an inclusion complex with dalbavancin that slows the formation of the major degradant, mannosyl aglycone (MAG). The effect of 2HPßCD is increased in the presence of Mg2+ and phosphate at pH 7.0, and the complex is more stable at a dalbavancin concentration of 1 mg/mL than at 20 mg/mL. These observations point towards the possibility of formulating a dalbavancin injection solution with a long shelf life at room temperature and physiological pH.

Anticancer Activity of Novel Difluorinated Curcumin Analog and Its Inclusion Complex with 2-Hydroxypropyl-ß-Cyclodextrin against Pancreatic Cancer.

Pancreatic ductal adenocarcinoma (PDAC) is the primary reason for cancer-related deaths in the US. Genetic mutations, drug resistance, the involvement of multiple signaling pathways, cancer stem cells (CSCs), and desmoplastic stroma, which hinders drug penetrance, contribute to poor chemotherapeutic efficacy. Hence, there is a need to identify novel drugs with improved delivery to improve treatment outcomes. Curcumin is one such compound that can inhibit multiple signaling pathways and CSCs. However, curcumin's clinical applicability for treating PDAC is limited because of its poor solubility in water and metabolic instability. Hence, we developed a difluorinated curcumin (CDF) analog that accumulates selectively in the pancreas and inhibits PDAC growth in vitro and in vivo. In the present work, we developed its 2-hydroxy-propyl-ß-cyclodextrin (HCD) inclusion complex to increase its water solubility and hydrolytic stability. The CDFHCD inclusion complex was characterized by spectroscopic, thermal, and microscopic techniques. The inclusion complex exhibited increased aqueous solubility, hydrolytic stability, and antiproliferative activity compared to parent CDF. Moreover, CDF and CDFHCD inhibited colony and spheroid formation, and induced cell cycle and apoptosis in PDAC cell lines. Hence, CDFHCD self-assembly is an efficient approach to increase water solubility and anticancer therapeutic efficacy, which now warrants advancement towards a clinical proof of concept in PDAC patients.

The Formulation of Curcumin: 2-Hydroxypropyl-ß-cyclodextrin Complex with Smart Hydrogel for Prolonged Release of Curcumin.

Curcumin comes from the plant species Curcuma longa and shows numerous pharmacological activities. There are numerous curcumin formulations with gels or cyclodextrins in order to increase its solubility and bioavailability. This paper presents the formulation of complex of curcumin with 2-hydroxypropyl-ß-cyclodextrin in a thermosensitive hydrogel, based on N-isopropylmethacrylamide and N-isopropylacrylamide with ethylene glycol dimethacrylate as a crosslinker. The product was characterized by chemical methods and also by FTIR, HPLC, DSC, SEM, XRD. The results show that synthesis was successfully done. With an increase in the quantity of crosslinker in the hydrogels, the starting release and the release rate of curcumin from the formulation of the complex with hydrogels decreases. The release rate of curcumin from the gel complex formulation is constant over time. It is possible to design a formulation that will release curcumin for more than 60 days. In order to determine the mechanism and kinetics of curcumin release, various mathematical models were applied by using the DDSolver package for Microsoft Excel application. The Korsmeyer-Peppas model best describes the release of curcumin from the gel formulation of the complex, while the values for the diffusion exponent (0.063-0.074) shows that mechanism of the release rate is based on diffusion.

Coalition of Biological Agent (Melatonin) With Chemotherapeutic Agent (Amphotericin B) for Combating Visceral Leishmaniasis via Oral Administration of Modified Solid Lipid Nanoparticles.

In this study, 2-hydroxypropyl-ß-cyclodextrin (HPßCD) grafted solid lipid nanoparticle (SLN)-based bioconjugate was synthesized and used for administering a combination of melatonin (Mel) and amphotericin B (AmB) orally for effective visceral leishmaniasis (VL) treatment. The formulations (HPCD-Mel-AmB SLN) were synthesized by the emulsion solvent evaporation method. HPCD-Mel-AmB SLN showed a high loading capacity and a high entrapment efficiency of AmB (% DL = 9.0 ± 0.55 and % EE = 87.9 ± 0.57) and Mel (% DL = 7.5 ± 0.51 and % EE = 63 ± 6.24). The cumulative percent release of AmB and Mel was 66.10 and 73.06%, respectively, up to 72 h. Time-dependent cellular uptake was noticed for HPCD-Mel-AmB SLN for 4 h. Further, HPCD-Mel-AmB SLN did not show any toxic effects on J774A.1 macrophages and Swiss albino mice. HPCD-Mel-AmB SLN (10 mg/kg ×5 days, p.o.) has significantly diminished (98.89%) the intracellular parasite load in liver tissues of L. donovani-infected BALB/c mice, subsequently highlighting the role of melatonin toward an effective strategy in combating leishmanial infection. Therefore, these results indicated that administration of HPCD-Mel-AmB SLN improve the therapeutic index of the first-line drug in addition to the introduction of biological agent and would be a promising therapeutic candidate for effective VL therapy. In the present study, the objective is to test the efficacy of the chemotherapeutic approach in combination with a biological immunomodulatory agent against leishmanial infection using in vitro and in vivo studies. This information suggests that melatonin could be an efficacious and potent antileishmanial agent.

2-Hydroxypropyl-ß-cyclodextrin mitigates pathological changes in a mouse model of retinal cholesterol dyshomeostasis.

CYP46A1 is a CNS-specific enzyme, which eliminates cholesterol from the brain and retina by metabolism to 24-hydroxycholesterol, thus contributing to cholesterol homeostasis in both organs. 2-Hydroxypropyl-ß-cyclodextrin (HPCD), a Food and Drug Administration-approved formulation vehicle, is currently being investigated off-label for treatment of various diseases, including retinal diseases. HPCD was shown to lower retinal cholesterol content in mice but had not yet been evaluated for its therapeutic benefits. Herein, we put Cyp46a1-/- mice on high fat cholesterol-enriched diet from 1 to 14 months of age (control group) and at 12 months of age, started to treat a group of these animals with HPCD until the age of 14 months. We found that as compared with mature and regular chow-fed Cyp46a1-/- mice, control group had about 6-fold increase in the retinal total cholesterol content, focal cholesterol and lipid deposition in the photoreceptor-Bruch's membrane region, and retinal macrophage activation. In addition, aged animals had cholesterol crystals at the photoreceptor-retinal pigment epithelium interface and changes in the Bruch's membrane ultrastructure. HPCD treatment mitigated all these manifestations of retinal cholesterol dyshomeostasis and altered the abundance of six groups of proteins (genetic information transfer, vesicular transport, and cytoskeletal organization, endocytosis and lysosomal processing, unfolded protein removal, lipid homeostasis, and Wnt signaling). Thus, aged Cyp46a1-/- mice on high fat cholesterol-enriched diet revealed pathological changes secondary to retinal cholesterol overload and supported further studies of HPCD as a potential therapeutic for age-related macular degeneration and diabetic retinopathy associated with retinal cholesterol dyshomeostasis.

Structural Studies of Piperine Inclusion Complexes in Native and Derivative ß-Cyclodextrins.

Piperine (PN), the primary pungent alkaloid in black pepper shows several biological activities such as antioxidant, antimicrobial and anti-cancerogenic effects. Similar to other alkaloids, PN is characterized by poor water solubility. One way to improve its solubility and thus its biological activities is by forming inclusion complexes with suitable cyclodextrins. In this work PN inclusion complexes in native ß-cyclodextrin (ß-CD), its methylated (randomly methylated (RM-ß-CD), heptakis-(2,6-di-O-methyl)-ß-CD (DM-ß-CD) and heptakis-(2,3,6-tri-O-methyl)-ß-CD (TM-ß-CD)) and 2-hydroxypropylated (HP-ß-CD) derivatives are investigated using physicochemical methods, such as phase solubility study and X-ray crystallography complemented by theoretical (molecular dynamics simulations) studies. The determination of the crystal structure of the PN inclusion complexes in ß-CD, DM-ß-CD and TM-ß-CD, reveals the formation of 1:2 guest:host inclusion complexes in the crystalline state. The guest PN molecule threads the hydrophobic cavities of the hosts which are arranged as couples in a tail-to-tail mode in the case of PN/ß-CD and in a head-to-tail mode in the cases of PN/DM-ß-CD and PN/TM-ß-CD. MD studies based on the crystallographically determined structures and docked models show the stability of the examined complexes in an aqueous environment whereas the binding affinity of PN for the host molecules is calculated by the MM/GBSA method. Finally, phase-solubility studies of PN with ß-CD, RM-ß-CD and HP-ß-CD are presented, indicating a Bs-type for the PN/ß-CD complex and an AL-type for the PN/RM-ß-CD and PN/HP-ß-CD complexes with 1:1 guest:host stoichiometry.