Enhancing Giardicidal Activity and Aqueous Solubility through the Development of "RetroABZ", a Regioisomer of Albendazole: In Vitro, In Vivo, and In Silico Studies.

Parasitic diseases, including giardiasis caused by Giardia lamblia (G. lamblia), present a considerable global health burden. The limited effectiveness and adverse effects of current treatment options underscore the necessity for novel therapeutic compounds. In this study, we employed a rational design strategy to synthesize retroalbendazole (RetroABZ), aiming to address the limitations associated with albendazole, a commonly used drug for giardiasis treatment. RetroABZ exhibited enhanced in vitro activity against G. lamblia trophozoites, demonstrating nanomolar potency (IC50 = 83 nM), outperforming albendazole (189 nM). Moreover, our in vivo murine model of giardiasis displayed a strong correlation, supporting the efficacy of RetroABZ, which exhibited an eleven-fold increase in potency compared to albendazole, with median effective dose (ED50) values of 5 µg/kg and 55 µg/kg, respectively. A notable finding was RetroABZ's significantly improved water solubility (245.74 µg/mL), representing a 23-fold increase compared to albendazole, thereby offering potential opportunities for developing derivatives that effectively target invasive parasites. The molecular docking study revealed that RetroABZ displays an interaction profile with tubulin similar to albendazole, forming hydrogen bonds with Glu198 and Cys236 of the ß-tubulin. Additionally, molecular dynamics studies demonstrated that RetroABZ has a greater number of hydrophobic interactions with the binding site in the ß-tubulin, due to the orientation of the propylthio substituent. Consequently, RetroABZ exhibited a higher affinity compared to albendazole. Overall, our findings underscore RetroABZ's potential as a promising therapeutic candidate not only for giardiasis but also for other parasitic diseases.

Phospholipid Complexation for Bioavailability Improvement of Albendazole: Preparation, Characterization and In Vivo Evaluation.

The current study aimed to improve the poor solubility of albendazole (ABZ) by means of phospholipid complexation, hence to improve its oral bioavailability. The solvent-evaporation method for ABZ-phospholipid complex (ABZ-PC) preparation was established for the first time. And a systematic optimization of preparation conditions of ABZ-PC was performed. Physicochemical studies of ABZ-PC were performed with FTIR, DSC, and XRD measurements to confirm the formation of the ABZ-PC and reveal the interaction mechanism between ABZ and phospholipid molecules. Solubility determination and morphological characterization were applied to verify the solubility improvement of prepared ABZ-PC. Moreover, the pharmacokinetic performance of ABZ-PC was further evaluated in vivo compared with raw materials of ABZ. Under optimal preparation conditions, the AE of ABZ-PC could be approximately 100%. Physicochemical studies indicated that the P = O group in the phospholipid molecule would interact with the N-H group in the ABZ molecule through hydrogen bonds and ABZ was dispersed in an amorphous state after being prepared into ABZ-PC. The aqueous solubility of ABZ-PC in deionized water (pH7.0) improved by 30-folds than free ABZ, and the AUC0-t of ABZ-PC was significantly increased by 2.32 times in comparison with raw materials of ABZ through oral administration. The current study developed an effective method for the phospholipid complexation of ABZ. With significantly improved solubility in an aqueous environment, the prepared ABZ-PC exhibited improved oral bioavailability and pharmacokinetic characteristics indicating it could be potentially applied in the oral drug delivery of ABZ.

Giardia duodenalis: Flavohemoglobin is involved in drug biotransformation and resistance to albendazole.

Giardia duodenalis causes giardiasis, a major diarrheal disease in humans worldwide whose treatment relies mainly on metronidazole (MTZ) and albendazole (ABZ). The emergence of ABZ resistance in this parasite has prompted studies to elucidate the molecular mechanisms underlying this phenomenon. G. duodenalis trophozoites convert ABZ into its sulfoxide (ABZSO) and sulfone (ABZSOO) forms, despite lacking canonical enzymes involved in these processes, such as cytochrome P450s (CYP450s) and flavin-containing monooxygenases (FMOs). This study aims to identify the enzyme responsible for ABZ metabolism and its role in ABZ resistance in G. duodenalis. We first determined that the iron-containing cofactor heme induces higher mRNA expression levels of flavohemoglobin (gFlHb) in Giardia trophozoites. Molecular docking analyses predict favorable interactions of gFlHb with ABZ, ABZSO and ABZSOO. Spectral analyses of recombinant gFlHb in the presence of ABZ, ABZSO and ABZSOO showed high affinities for each of these compounds with Kd values of 22.7, 19.1 and 23.8 nM respectively. ABZ and ABZSO enhanced gFlHb NADH oxidase activity (turnover number 14.5 min-1), whereas LC-MS/MS analyses of the reaction products showed that gFlHb slowly oxygenates ABZ into ABZSO at a much lower rate (turnover number 0.01 min-1). Further spectroscopic analyses showed that ABZ is indirectly oxidized to ABZSO by superoxide generated from the NADH oxidase activity of gFlHb. In a similar manner, the superoxide-generating enzyme xanthine oxidase was able to produce ABZSO in the presence of xanthine and ABZ. Interestingly, we find that gFlHb mRNA expression is lower in albendazole-resistant clones compared to those that are sensitive to this drug. Furthermore, all albendazole-resistant clones transfected to overexpress gFlHb displayed higher susceptibility to the drug than the parent clones. Collectively these findings indicate a role for gFlHb in ABZ conversion to its sulfoxide and that gFlHb down-regulation acts as a passive pharmacokinetic mechanism of resistance in this parasite.

Quantitative Analysis of Abamectin, Albendazole, Levamisole HCl and Closantel in Q-DRENCH Oral Suspension Using a Stability-Indicating HPLC-DAD Method.

Combination therapy of many anthelmintic drugs has been used to achieve fast animal curing. Q-DRENCH is an oral suspension, containing four different active drugs against GIT worms in sheep, commonly used in Australia and New Zeeland. The anti-parasitic drugs are Albendazole (ALB), Levamisole HCl (LEV), Abamectin (ABA), and Closantel (CLO). The main purpose of this study is to present a new simultaneous stability-indicting HPLC-DAD method for the analysis of the four drugs. The recommended liquid system was 1 mL of Triethylamine/L water, adjusting the pH to 3.5 by glacial acetic acid: acetonitrile solvent (20:80, v/v). Isocratic elusion achieved the desired results of separation at a 2 mL/min flow rate using Zorbax C-18 as a stationary phase. Detection was performed at 210 nm. The linearity ranges were 15.15 to 93.75 µg/mL for ALB, 25 to 150 µg/mL for LEV, 30 to 150 µg/mL for ABA, and 11.7 to 140.63 µg/mL for CLO. Moreover, the final greenness score was 0.62 using the AGREE tool, which reflects the eco-friendly nature. Moreover, the four drugs were determined successfully in the presence of their stressful degradation products. This work presents the first chromatographic method for simultaneous analysis for Q-DRENCH oral suspension drugs in the presence of their stressful degradation products.

Elimination of Giardia duodenalis BIV in vivo using natural extracts in microbiome and dietary supplements.

In this study, a combination therapy of several natural products was evaluated in vivo in the Giardia duodenalis infection model. G. duodenalis infected mice were treated as follows: distilled water (infected control C+), BIOintestil® (BIO; natural products of Cymbopogon martinii and Zingiber officinale), MicrobiomeX® (MBX; extract of Citrus sinensis and Citrus paradisi), MBX + BIO, Camellia sinensis tea (CPR; black tea). These natural compounds were administered in a dose of 100 mg/day and were compared to G. duodenalis-infected mice treated with albendazole (ALB; 50 mg/Kg/day) and metronidazole (MET; 500 mg/Kg/day), the conventional therapies used to this day. One group remained un-infected and untreated as our control group (C-). Treatment started 8 days after infection, and after 5 days of treatment (7 days for MET), all animals were followed for 15 days. We continuously checked for the presence of G. duodenalis by Faust method, in association with detection of the parasite by PCR from feces, as well for the presence of trophozoites in the intestinal mucosa after sacrifice. Animals treated with MBX, BIO and MBX + BIO presented an undetectable parasitic load until the 15th day of monitoring, while animals treated with CPR, MET and ALB continued to release cysts. Animals in the MBX, MBX + BIO, ALB groups consumed lower feed, MBX, CPR, MET had greater weight and MBX, MBX + BIO, BIO, CPR, C- consumed more water when compared to infected-group control. MBX and BIO alone or associated eliminated G. duodenalis without apparent adverse effects and animals of these groups showed better clinical performance in relation to those with high parasitic load. MET, ALB and CPR only decreased the number of cysts, indicating limitations and therapeutic failure.

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: The aim of the study was to analyze through in vitro and in silico studies (Autodock Vina software and CycloMolder platform) the formation of inclusion complexes between ABZ, ß-cyclodextrin (ß-CD) and its derivatives Methyl-ß-cyclodextrin (M-ß-CD) and Hydroxypropyl-ß-cyclodextrin (HP-ß-CD). 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-ß-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 generate gains in the stability of the complex. On the characterization tests, the complexes experimentally obtained by the kneading method demonstrated highly suggestive parameters, including ABZ in HP-ß-CD in both molar proportions, 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, dissolution efficiency of up to 92%. CONCLUSION: In silico studies provided a rational selection of the appropriate complexes of cyclodextrin, enabling the elaboration of more targeted complexes, decreasing time and costs for elaboration of new formulations, thereby increasing the oral biodisponibility of ABZ.

Dissolution/Permeation of Albendazole in the Presence of Cyclodextrin and Bile Salts: A Mechanistic In Vitro Study into Factors Governing Oral Bioavailability.

We aimed to understand the impact of the interplay between bile salts and cyclodextrins on the dissolution-permeation of poorly soluble drug compounds with a moderate-strong binding constant to cyclodextrin. Phase diagrams were prepared on the chosen model compound albendazole in phosphate buffer, fasted state simulated intestinal fluid (FaSSIF), and a modified fed state simulated intestinal fluid (FeSSIFmod) with (2-hydroxypropyl)-beta-cyclodextrin (HP-ß-CD) concentrations of up to 10 % (m/m). Then we investigated the dissolution/permeation interplay of albendazole dissolved/suspended in the different media through a biomimetic barrier on a 96-well in vitro model. The apparent solubility of albendazole was enhanced by HP-ß-CD and FaSSIF/FeSSIFmod separately. However, when albendazole was dissolved in HP-ß-CD and biomimetic media together, the solubility was significantly lower than the predicted additive solubility from the solubilizing effects. It is postulated that this is due to the sodium taurocholate from the biomimetic media displacing albendazole from the hydrophobic cavity of HP-ß-CD. In the permeation experiments, the highest permeation was observed at cyclodextrin concentrations able to solubilize close to the total dose of albendazole without a major surplus of solubilization capacity. Furthermore, an over-proportional permeation enhancement was observed when both, cyclodextrin and biomimetic media were present. These results indicate that the interplay between bile salts and cyclodextrins can enhance the free (molecularly dissolved) fraction of drug in solution to a greater extent than could be obtained with one of the solubilizing components alone. In conclusion, at carefully selected cyclodextrin-concentrations in combination with biomimetic media, obviously, a transient supersaturation is induced, which is made responsible for the observed major permeation enhancement.

Exploration on the drug solubility enhancement in aqueous medium with the help of endo-functionalized molecular tubes: a computational approach.

One major problem in the pharmaceutical industry is the aqueous solubility of newly developed orally administered drug candidates. More than 50% of newly developed drug molecules suffer from low aqueous solubility. The therapeutic effects of drug molecules are majorly dependent on the bioavailability and, in essence, on the solubility of the used drug molecules. Thus, enhancement of drug solubility of sparingly soluble drug molecules is a need of modern times. Considering the high importance of drug solubility, we have computationally shown the enhancement of drug solubility for seven class II (poorly water-soluble) drug molecules in a water medium. The uses of supramolecular macrocycles have immense importance in the same field. Thus, we have used two synthetic supramolecular receptors named host-1a and host-1b to enhance the water solubility of fluorouracil, albendazole, camptothecin, clopidogrel, indomethacin, melphalan, and tolfenamic acid drug molecules. Biomedical engagements of a supramolecular receptor commence with the formation of stable host-drug complexes. These complexations enhance the water solubility of drug molecules and sustain the release rate and bioavailability of drug molecules. Thus, in this work, we focus on the formation of stable host-drug complexes in water medium. Molecular dynamics simulation is applied to analyze the structural features and the energetics involved in the host-drug complexation process. The information obtained at the atomistic level helps us gain better insights into the key interactions that operate to produce such highly stable complexes. Thus, we can propose that these two supramolecular receptors may be used as drug solubilizing agents, and patients will benefit from this theragnostic application shortly.

Anti-trypanosomal and anthelminthic properties of ethanol and aqueous extracts of Tetrapleura tetraptera Taub.

Trypanosomosis and helminthosis, considered as part of neglected tropical diseases, are parasitic infections of public health importance, especially in Africa. Medicinal plants have been used in most parts of Africa, to treat these parasitic infections. The study aims to determine the anti-trypanosomal and anthelminthic properties of Tetrapleura tetraptera (fruit and stembark). The aqueous extracts of T. tetraptera fruit (TTFaq) and stembark (TTSaq), as well as ethanol extracts of T. tetraptera fruit (TTFe) and stembark (TTSe), were screened for their in vitro anti-trypanosomal and anthelminthic activities against T. b. brucei and Pheretima posthuma worms, respectively. Preliminary phytochemical screening of all extracts and gas chromatography-mass spectrometry (GC-MS) analysis of most active extracts were conducted. TTFaq exhibited anti-trypanosomal activity with IC50 of 18.18 µg/mL. TTSe and TTFe had moderate anti-trypanosomal activity with IC50 of 34.76 and 34.84 µg/mL, respectively. TTSaq had relatively low activity against the parasite with IC50 of 55.03 µg/mL. The SI of T. tetraptera extracts was between the range of 0.14-2.09. TTFaq showed dose-dependent activity causing paralysis and death of the adult worms at all concentrations. At the least concentration of 0.625 mg/mL, TTFaq induced paralysis and death after 101.88 ± 0.8 and 242.64 ± 0.38 min of exposure, respectively compared with the negative control (p < 0.0001). TTFe, TTSe and TTSaq caused paralysis of worms after 318.32 ± 0.74, 422.5 ± 0.72, 422.20 ± 0.55 min of exposure at minimum concentrations of 2.5, 10 and 5 mg/mL, respectively (p < 0.0001). However, no death was observed in worms treated with TTFe, TTSe and TTSaq at all test concentrations. In the presence of sub-minimal inhibitory concentration of the extracts, TTFaq potentiated the anthelminthic activity of albendazole whiles TTFe, TTSaq and TTSe inhibited the activity of albendazole. Phytochemical screening revealed the presence of saponins, triterpenoids, reducing sugars, flavonoids (absent in TTFe), steroids (absent in TTFaq) and tannins (absent in TTSe and TTFe) in the extracts. GC-MS revealed the presence of 9-octadecenamide and betulic acid in TTFaq. Hence, there was evidence provided here that Tetrapleura tetraptera may be effective. This gives credence to their folkloric use. However, further study might be necessary to ascertain safety use in both humans and animals.

Biomediated synthesis, characterization, and biological applications of nickel oxide nanoparticles derived from Toona ciliata, Ficus carica and Pinus roxburghii.

Biomediated ecofriendly method for the synthesis of nickel oxide nanoparticles using plants extracts (Toona ciliata, Ficus carica and Pinus roxburghii) has been reported. The nanoparticles so obtained were characterized by various techniques such as ultraviolet-visible, powder X-ray diffraction, Fourier transform infrared spectroscopy, attenuated total reflectance spectroscopy, scanning electron microscopy, transmission electron microscopy, energy dispersive X-ray spectroscopy, thermogravimetric analysis and fluorescence spectroscopy. Formation of nickel oxide nanoparticles was confirmed by Fourier transform infrared spectroscopy and X-ray diffraction where the former technique ascertains the formation of bond between nickel and oxygen. The nickel oxide nanoparticles were found to be crystalline cubic face centered and show intense photoluminescence emission at 416, 414 and 413 nm, respectively. The antibacterial activity was studied against gram positive and gram negative bacterial species by agar well diffusion method. The nickel oxide nanoparticles show better activity against some bacterial strains with reference to the standard drugs Ciprofloxacin and Gentamicin. The anthelmintic activity against Pheretima posthuma of nanomaterials obtained from Pinus roxburghii was found to be greater than that derived from Toona ciliata and Ficus carica using the standard drug Albendazole. This method takes the advantage of the sustainable and economic approach for the synthesis of metal oxide nanoparticles.

Copper nanoparticles: Biosynthesis, characterization, and protoscolicidal effects alone and combined with albendazole against hydatid cyst protoscoleces.

BACKGROUND: Surgery remains the preferred treatment option for hydatid cyst (cystic echinococcosis); however, recent studies have demonstrated that the current protoscolicidal agents used during surgery are associated with some adverse side effects such as biliary fibrosis, hepatic necrosis, and cirrhosis. The present study aims to evaluate the in vitro and ex vivo anti-parasitic effects of copper nanoparticles (CuNPs) alone and combined with albendazole on hydatid cyst protoscoleces. METHODS: CuNPs was green synthesized using C. spinosa extract. Various concentrations of CuNPs (250, 500, and 750 mg/mL) alone and combined with albendazole (ALZ, 200 mg/mL) were exposed to protoscoleces collected from the liver fertile hydatid cysts of infected sheep for 5-60 min in vitro and ex vivo. Next, the eosin exclusion test was applied to determine the viability of protoscoleces. Caspase-3 like activity of CuNPs-treated protoscoleces was then evaluated using the colorimetric protease assay Sigma Kit based on the manufacturer's instructions. RESULTS: Scanning electron microscopy (SEM) results showed that the particle size of CuNPs was 17 and 41 nm with the maximum peak at the wavelength of 414 nm. The maximum protoscolicidal activity of CuNPs was observed at the concentration of 750 mg/mL in vitro, so that 73.3 % of protoscoleces were killed after 60 min of exposure. Meanwhile, the mortality of protoscoleces was 100 % after 10 min of exposure to 750 mg/mL of CuNPs along with ALZ (200 mg/mL). Nevertheless, the findings proved that CuNPs even in combination with ALZ required a longer time to kill protoscoleces ex vivo. After 48 h of treating protoscoleces, CuNPs in a dose-dependent manner and at doses of 250, 500, and 750 mg/mL induced the caspase enzyme activation by 20.5 %, 32.3 %, and 36.1 %, respectively. CONCLUSION: The findings of the present investigation showed potent protoscolicidal effects of CuNPs, especially combined with albendazole, which entirely eliminated the parasite after 10-20 min of exposure. The results also showed that although the possible protoscolicidal mechanisms of CuNPs are not clearly understood, the inducing apoptosis through caspases is one of the main protoscolicidal mechanisms of CuNPs. However, supplementary studies, especially in animal models and clinical settings, are needed to approve these results.

Solid Polymeric Nanoparticles of Albendazole: Synthesis, Physico-Chemical Characterization and Biological Activity.

Albendazole is a benzimidazole derivative with documented antitumor activity and low toxicity to healthy cells. The major disadvantage in terms of clinical use is its low aqueous solubility which limits its bioavailability. Albendazole was incorporated into stable and homogeneous polyurethane structures with the aim of obtaining an improved drug delivery system model. Spectral and thermal analysis was used to investigate the encapsulation process and confirmed the presence of albendazole inside the nanoparticles. The in vitro anticancer properties of albendazole encapsulated in polyurethane structures versus the un-encapsulated compound were tested on two breast cancer cell lines, MCF-7 and MDA-MB-231, in terms of cellular viability and apoptosis induction. The study showed that the encapsulation process enhanced the antitumor activity of albendazole on the MCF-7 and MDA-MB-23 breast cancer lines. The cytotoxic activity manifested in a concentration-dependent manner and was accompanied by changes in cell morphology and nuclear fragmentation.

A new approach for microextraction of trace albendazole sulfoxide drug from the samples of human plasma and urine, and water by the molecularly imprinted polymer nanoparticles combined with HPLC.

In this research study, a method of dispersive-micro-solid phase extraction (D-µ-SPE) combined with molecularly imprinted polymer nanoparticles (MIP-NPs) with HPLC-UV was developed for the fast and selective detection of the trace amount of albendazole sulfoxide (ABZSO) in the biological samples. To investigate the effective factors on ABZSO microextraction by the method, central composite design (CCD) was utilized, and the optimum conditions for ABZSO microextraction were sample pH of 8.0, MIP-mass of 15 mg, sonication time of 12 min, and eluent (methanol) volume of 0.25 mL. Under the obtained optimal extraction conditions, the value for the limit of detection (LOD) and limit of quantification (LOQ) was respectively showed to be 0.074 and 0.246 ng mL-1. In addition, the calculated peak areas exhibited a linear relationship with the ABZSO concentration ranging from 0.4 to 4200 ng mL-1. The analyses of the samples including human plasma and urine, and water were successfully performed by the usage of the D-µ-SPE method, which was a simple and sensitive technique and a suitable alternative for the analysis of ABZSO. In the analysis of ABZSO in various samples, the recoveries at various levels of ABZSO concentrations (50, 300, and 500 ng mL-1) were in the range of 95.7-103.0 %, and the relative standard deviations (RSDs; n = 3) varied from 2.2 to 4.4%.

Evaluation of the efficacy of albendazole sulfoxide (ABZ-SO)-loaded chitosan-PLGA nanoparticles in the treatment of cystic echinococcosis in laboratory mice.

Albendazole is known as the drug of choice for medical treatment of cystic echinococcosis (CE). Albendazole sulfoxide (ABZ-SO), as the main active metabolite of albendazole, has low efficacy in the disease due to low water solubility and poor absorptivity. PLGA nanoparticles (NPs) enhance the dissolution of poorly soluble drugs, and chitosan (CS) coating enhances oral drug delivery of NPs. In this study, the efficacy of ABZ-SO-loaded CS-PGLA NPs in the treatment of CE was evaluated in laboratory mice. ABZ-SO-loaded CS-PGLA NPs were prepared by nanoprecipitation and characterized by dynamic light scattering method and scanning electron microscopy. Thirty mice were intraperitoneally infected by 1000 protoscoleces of Echinococcus granulosus. Ten months later, the mice were allocated into 3 groups: groups 1 and 2 were treated with ABZ-SO and ABZ-SO-loaded CS-PGLA NPs, respectively, and the mice in group 3 remained untreated as the control group. The drugs were administered by gavage for 45 days at a daily dose of 10 mg/kg. Finally, all mice were opened and the cysts were collected, counted, weighed, and measured separately. The therapeutic effect of ABZ-SO in the number, weight, and volume of the cysts were not statistically significant compared with those in ABZ-SO-loaded CS-PGLA NPs and the control group. However, the therapeutic effect of ABZ-SO-loaded CS-PGLA NPs in the weight and volume of cysts were statistically significant when compared with that in the control group (p ˂ 0.05). In conclusions, this study revealed that ABZ-SO-loaded CS-PGLA NPs could enhance the therapeutic efficacy of ABZ-SO in the treatment of CE in laboratory mice.

Convergent click synthesis of macromolecular dendritic ß-cyclodextrin derivatives as non-conventional drug carriers: Albendazole as guest model.

From a materials science perspective, herein we present the design and synthesis of six macromolecular carbohydrate derivatives, obtained by combining the native cyclic oligosaccharide ßCD and dendritic poly(ester) moieties, coupled by CuAAc click reactions, in a convergent fashion. We envisioned two structural variables to promote the formation of inclusion complexes (ICs) with the anti-parasitic drug Albendazole, the degree of substitution on the ßCD (mono or hepta-substitution) and the dendritic generation (from first to third). In terms of synthetic effort and cost, the mono-substituted ßCD derivatives were obtained in more approachable experimental conditions in comparison to the ßCD dendrimers (hepta-substituted macrocycle). The six dendritic derivatives were more soluble in water and showed better complexation capacity than native ßCD. For both, mono and hepta-substituted ßCD, we observed that the amount of encapsulated ABZ increases when the dendron generation increases. Interestingly, different degrees of substitution (mono and hepta) lead comparable results of ABZ complexation. In conclusion, the encapsulation performance and the consequent solubility enhancement, make these molecular containers excellent materials to positively impact the therapeutic desirability of ABZ.

Anthelmintic Activity of Yeast Particle-Encapsulated Terpenes.

Soil-transmitted nematodes (STN) infect 1-2 billion of the poorest people worldwide. Only benzimidazoles are currently used in mass drug administration, with many instances of reduced activity. Terpenes are a class of compounds with anthelmintic activity. Thymol, a natural monoterpene phenol, was used to help eradicate hookworms in the U.S. South circa 1910. However, the use of terpenes as anthelmintics was discontinued because of adverse side effects associated with high doses and premature stomach absorption. Furthermore, the dose-response activity of specific terpenes against STNs has been understudied. Here we used hollow, porous yeast particles (YPs) to efficiently encapsulate (>95%) high levels of terpenes (52% w/w) and evaluated their anthelmintic activity on hookworms (Ancylostoma ceylanicum), a rodent parasite (Nippostrongylus brasiliensis), and whipworm (Trichuris muris). We identified YP-terpenes that were effective against all three parasites. Further, YP-terpenes overcame albendazole-resistant Caenorhabditis elegans. These results demonstrate that terpenes are broad-acting anthelmintics. Terpenes are predicted to be extremely difficult for parasites to resist, and YP encapsulation provides water-suspendable terpene materials without surfactants and sustained terpene release that could lead to the development of formulations for oral delivery that overcome fast absorption in the stomach, thus reducing dosage and toxic side effects.

Albendazole solid dispersions prepared using PEG6000 and Poloxamer188: formulation, characterization and in vivo evaluation.

This study aimed to optimize the preparation process of albendazole (ABZ) solid dispersion (SD) and enhance its dissolution rate and oral bioavailability in dogs. The ABZ-SD formulations were prepared by a fusion method with ABZ and polyethylene glycol 6000 (PEG 6000), poloxamer 188 (P 188) polymers at various weight ratios or the combination of PEG 6000&P 188. The characterizations of the optimal formulations were performed by scanning electron microscopy (SEM), powder X-ray diffraction (PXRD), Fourier transform infrared spectroscopy (FTIR), in vitro dissolution test and molecular docking. The in vivo pharmacokinetic study was conducted in beagle dogs. As a result, ABZ solid dispersion based on PEG 6000&P 188 (1:2) was successfully prepared. The ABZ-SD formulation could significantly improve the apparent solubility and dissolution rate of ABZ compared with commercial tablets. Furthermore, the water solubility of ABZ-SD was improved mainly based on hydrogen bond association. Besides, at an oral dosage of 15 mg/kg ABZ, the SDs had higher Cmax values and areas under the curve (AUCs) compared to those of commercial ABZ tablets. Preparation of ABZ-loaded SDs by PEG 6000&P 188 is a promising strategy to improve the oral bioavailability of ABZ.

Effect of Genotype and Sex of the Host on the Bioavailability of Novel Albendazole Microcrystals Based on Chitosan and Cellulose Derivatives.

Albendazole (ABZ), an anthelmintic compound widely used in the treatment of systemic nematode infections, is included in the list of class II drugs based on the Biopharmaceutical Classification System. ABZ has limited effectiveness due to its poor water solubility and consequent low bioavailability. Bioavailability of novel ABZ microcrystals based on hydroxyethylcellulose (S4A) or chitosan (S10A) was studied in male and female mice of two inbred lines, from the murine CBi-IGE model of trichinellosis, differing in susceptibility to this parasitosis (line CBi/L, resistant; line CBi+, susceptible). ABZ microcrystals were administered orally, and albendazole sulfoxide (ABZSO) was quantified in plasma by high-performance liquid chromatography. Mice given the microcrystals showed a significant increase in maximum plasmatic concentration (Cmax) compared with those receiving pure ABZ (P < 0.01). In both genotypes, males and females given S4A had higher Cmax than those receiving S10A (P < 0.05). CBi/L showed a greater Cmax than CBi+ (significantly different only in females treated with S4A (P = 0.001)). CBi/L females attained a higher Cmax than males (P < 0.05). No sex effect was observed for this variable in CBi+ (P > 0.05). The results of the pharmacokinetic analysis indicate that the microcrystalline formulations optimize ABZ bioavailability, both in males and females, S4A being the best system in CBi/L mice and S10A in CBi+. In summary, the microcrystals increased ABZ bioavailability, and under the conditions of this investigation, both host genotype and sex influenced the pharmacokinetic parameters measured.

Synthesis, characterization and antiparasitic activity of organometallic derivatives of the anthelmintic drug albendazole.

Helminthiases, a group of neglected tropical diseases, affect more than one billion people mainly in tropical and subtropical regions. Moreover, major intestinal protozoa have a significant impact on global public health. Albendazole (ABZ) is a broad-spectrum anthelmintic recommended by the World Health Organisation (WHO). However, drug resistance is emerging due to its widespread use. In order to tackle this problem, taking into account the spectacular results obtained with ferroquine, an organometallic derivatization of the antimalarial drug chloroquine, we have prepared, in this study, a series of new ferrocenyl and ruthenocenyl derivatives of the organic drug ABZ and assessed their activity against different helminths and protozoans, namely Trichuris muris, Heligmosomoides polygygrus, Schistosoma mansoni, Giardia lamblia, Haemonchus contortus and Toxoplasma gondii. The ferrocene-containing ABZ analogue 2d exhibited over 70% activity against T. muris adults in vitro at 200 µM and no toxicity to mammalian cells (IC50 >100 µM). H. polygyrus adults were not affected by any of the derivatives tested. Against T. gondii, the ferrocene-containing ABZ analogues 1a and 2d showed better in vitro activity than ABZ and low toxicity to the host cells. The activity of the analogous ruthenocenyl compound 2b against S. mansoni and T. gondii in vitro might be attributed to its toxicity towards the host cells rather than a specific antiparasitic activity. These results demonstrate that the derivatives show a species specific in vitro activity and the choice of the organometallic moieties attached to the organic drug is playing a very important role. Two of our organometallic compounds, namely 1b and 2d, were tested in T. muris infected mice. At a 400 mg kg-1 dose, the compounds showed moderate worm burden reductions but low worm expulsion rates. Overall, this work, which is one of the first studies reporting the potential of organometallic compounds on a very broad range of parasitic helminths and protozoan, is a clear confirmation of the potential of organometallic complexes against parasites of medical and veterinary importance.

Characterisation of the in vitro activity of a Nitazoxanide-N-methyl-1H-benzimidazole hybrid molecule against albendazole and nitazoxanide susceptible and resistant strains of Giardia intestinalis and its in vivo giardicidal activity.

BACKGROUND: It was previously demonstrated that CMC-20, a nitazoxanide and N-methyl-1H-benzimidazole hybrid molecule, had higher in vitro activity against Giardia intestinalis WB strain than metronidazole and albendazole and similar to nitazoxanide. OBJETIVES: To evaluate the in vitro activity of CMC-20 against G. intestinalis strains with different susceptibility/resistance to albendazole and nitazoxanide and evaluate its effect on the distribution of parasite cytoskeletal proteins and its in vivo giardicidal activity. METHODS: CMC-20 activity was tested against two isolates from patients with chronic and acute giardiasis, an experimentally induced albendazole resistant strain and a nitazoxanide resistant clinical isolate. CMC-20 effect on the distribution of parasite cytoskeletal proteins was analysed by indirect immunofluorescence and its activity was evaluated in a murine model of giardiasis. FINDINGS CMC-20: showed broad activity against susceptible and resistant strains to albendazole and nitaxozanide. It affected the parasite microtubule reservoir and triggered the parasite encystation. In this process, alpha-7.2 giardin co-localised with CWP-1 protein. CMC-20 reduced the infection time and cyst load in feces of G. muris infected mice similar to albendazole. MAIN CONCLUSIONS: The in vitro and in vivo giardicidal activity of CMC-20 suggests its potential use in the treatment of giardiasis.