Thrombotic microenvironment responsive crosslinking cyclodextrin metal-organic framework nanocarriers for precise targeting and thrombolysis

Global public health is seriously threatened by thrombotic disorders because of their high rates of mortality and disability. Most thrombolytic agents, especially protein-based pharmaceuticals, have a short half-life in circulation, reducing their effectiveness in thrombolysis. The creation of an intelligent drug delivery system that delivers medication precisely and releases it under regulated conditions at nearby thrombus sites is essential for effective thrombolysis. In this article, we present a unique medication delivery system (MCRUA) that selectively targets platelets and releases drugs by stimulation from the thrombus' microenvironment. The thrombolytic enzyme urokinase-type plasminogen-activator (uPA) and the anti-inflammatory medication Aspirin (acetylsalicylic acid, ASA) are both loaded onto pH-sensitive CaCO3/cyclodextrin crosslinking metal-organic frameworks (MC) that make up the MCRUA system. c(RGD) is functionalized on the surface of MC, which is functionalized by RGD to an esterification reaction. Additionally, the thrombus site's acidic microenvironment causes MCRUA to disintegrate to release uPA for thrombolysis and aiding in vessel recanalization. Moreover, cyclodextrin-encapsulated ASA enables the treatment of the inflammatory environment within the thrombus, enhancing the antiplatelet aggregation effects and promoting cooperative thrombolysis therapy. When used for thrombotic disorders, our drug delivery system (MCRUA) promotes thrombolysis, suppresses rethrombosis, and enhances biosafety with fewer hemorrhagic side effects.

Long-term efficacy of intrathecal cyclodextrin in patients with Niemann-Pick disease type C

BACKGROUND AND OBJECTIVES

Niemann-Pick type C (NPC) is a rare lysosomal storage disease characterized by hepatosplenomegaly and progressive neurological deterioration due to abnormal intracellular cholesterol transport. Cyclic oligosaccharide 2-hydroxypropyl-β-cyclodextrin (HPBCD) is an effective treatment for NPC; however, few reports have shown its long-term efficacy and safety. To demonstrate long-term efficacy and safety of intrathecal HPBCD (IT-HPBCD) treatment for NPC, we herein reports five patients with NPC treated using IT-HPBCD for 4-11 years.

CASES AND RESULTS

Patients' ages at the onset ranged from 1.5 to 20 years. Notably, all patients showed rapid disease progression despite treatment with miglustat before IT-HPBCD treatment. Similarly, some patients showed transient improvement; however, all patients' conditions stabilized after long-term IT-HPBCD therapy. Mild-to-moderate hearing loss was observed in three patients. Furthermore, long-term treatment with IT-HPBCD may suppress neurological deterioration in patients with NPC; however, patients still experience some disease progression.

CONCLUSIONS

Long-term treatment with IT-HPBCD may suppress neurological deterioration in patients with NPC; however, the treatment outcome is dependent on the neurological status at the time of diagnosis, and disease progression is not completely inhibited. Awareness of the disease and newborn screening is needed for earlier disease detection. In addition, further optimization of the treatment protocol and additional treatments are needed to improve patient outcomes.

Bioavailability enhancement of sildenafil citrate via hydrogel-forming microneedle strategy in combination with cyclodextrin complexation

Sildenafil citrate (SIL) as a first-line treatment for erectile dysfunction is currently reported to have poor solubility and bioavailability. Moreover, SIL undergoes first-pass metabolism when taken orally and its injection can lead to discomfort. In this study, we introduce a novel transdermal delivery system that integrates hydrogel-forming microneedles with the inclusion complex tablet reservoir. The hydrogel-forming microneedle was prepared from a mixture of polymers and crosslinkers through a crosslinking process. Importantly, the formulations showed high swelling capacity (>400 %) and exhibited adequate mechanical and penetration properties (needle height reduction < 10 %), penetrating up to five layers of Parafilm® M (assessed to reach the dermis layer). Furthermore, to improve the solubility of SIL in the reservoir, the SIL was pre-complexed with β-cyclodextrin. Molecular docking analysis showed that SIL was successfully encapsulated into the β-cyclodextrin cavity and was the most suitable conformation compared to other CD derivatives. Moreover, to maximize SIL delivery, sodium starch glycolate was also added to the reservoir formulation. As a proof of concept, in vivo studies demonstrated the effectiveness of this concept, resulting in a significant increase in AUC (area under the curve) compared to that obtained after administration of pure SIL oral suspension, inclusion complex, and Viagra® with relative bioavailability > 100 %. Therefore, the approach developed in this study could potentially increase the efficacy of SIL in treating erectile dysfunction by being non-invasive, safe, avoiding first-pass metabolism, and increasing drug bioavailability.

Synergistic treatment of androgenetic alopecia with follicular co-delivery of minoxidil and cedrol in metal-organic frameworks stabilized by covalently cross-linked cyclodextrins

Androgenetic alopecia seriously affects the physical and mental health of patients. The main clinical therapeutic agent, minoxidil tincture, is challenged by solvent irritation and dose-dependent side effects. Our recent work has identified a biosafety natural product, cedrol, that is synergistic in combination with minoxidil, thereby improving medication safety by substantially reducing the clinical dose of minoxidil. In addition, ccross-linked CD-MOF were designed as carriers for hair follicle delivery, and γ-CD in the carriers was cross-linked by diphenyl carbonate with covalent bonds to protect the CD-MOF from rapid disintegration in an aqueous environment. This improved nanocarrier has a drug loading of 25%, whereas nanocarriers increased drug delivery to the hair follicles through ratchet effect, and increased human dermal papilla cells uptake of drugs via endocytosis pathways mainly mediated by lattice proteins, energy-dependent active transport, and lipid raft-dependent, thus improved cell viability, proliferation, and migration, followed by significantly enhancing the anti-androgenetic alopecia effect, with cedrol focusing on inhibiting 5α-reductase and activating Shh/Gli pathway, and minoxidil, which up-regulated VEGF, down-regulated TGF-β, and activated ERK/AKT pathway. This drug combination provides a new therapeutic strategy for androgenetic alopecia, while the newly developed cross-linked CD-MOF has been shown to serve as a promising follicular delivery vehicle.

Cyclodextrins as therapeutic drugs for treating lipid metabolism disorders

OBJECTIVE

This study sought to systematically compare the efficacy and mechanism of cyclodextrins as drug interventions in lipid metabolism diseases, potentially providing ideas for subsequent research directions and clinical applications.

METHODS

We used the bibliometric method for feature mining, applied VOSviewer software for clustering analysis, and applied content analysis for objective descriptions and accurate analysis.

RESULTS

(1) We collected more than 50 studies, which is the basic database of this study. (2) The academic bubble map showed that this research area was popular in the United States. (3) Cluster analysis showed that the intensively studied diseases in this field were Niemann-Pick type C (NPC), atherosclerosis (AS), and obesity. The hot-spot cyclodextrin types were HP-β-CD. (4) Literature measurement revealed the involvement of 15 types of lipid metabolism diseases. Among them, NPC, diabetes, and obesity were studied in clinical trials. Dyslipidemia and AS have been reported relatively more frequently in animal experiments. The studies of cellular experiments provide insight into the molecular mechanisms that intervene in lipid metabolism diseases from multiple perspectives. The exploration of the molecular mechanisms by which cyclodextrins exert their pharmacological effects mainly revolves around lipid metabolism.

CONCLUSION

It is worthwhile to investigate the role and mechanism of cyclodextrins in other lipid metabolism diseases. The potential efficacy evaluation of cyclodextrins as pharmaceutical drugs for oral or injectable formulations is less studied and may become a new focus in the future.

Efficient oral delivery of resveratrol-loaded cyclodextrin-metal organic framework for alleviation of ulcerative colitis

Developing innovative strategies for the oral administration of phytochemicals presents a promising approach to addressing intestinal diseases. However, numerous challenges persist, including limited therapeutic efficacy, poor bioavailability, and inadequate biocompatibility. In this study, we employed a cross-linked cyclodextrin-metal organic framework (CDF) to encapsulate resveratrol (Res), generating Res-CDF, which was subsequently incorporated into natural polysaccharide hydrogel microspheres (Res-CDF in MPs) for targeted oral delivery to alleviate ulcerative colitis (UC). The underlying adsorption mechanism of Res by γ-CD elucidated by molecular dynamics simulations. Importantly, the Res-CDF in MPs formulation protected against gastric acid degradation while preserving the bioactivity of Res. Moreover, the design enabled specific release of Res-CDF in response to the mildly alkaline environment of the intestinal tract, followed by sustained Res release. In UC mice model, Res-CDF in MPs demonstrated potent anti-inflammatory effects by attenuating pro-inflammatory cytokine production and exhibited antioxidant properties. Additionally, Res-CDF in MPs enhanced the expression of tight junction proteins ZO-1, Occludin, and mucin-2 (Muc-2), thereby maintaining normal intestinal barrier function. This innovative oral delivery strategy capitalizes on the advantageous properties of polysaccharide hydrogel and CDF to augment bioavailability of phytochemicals, laying the groundwork for developing novel oral interventions employing natural phytochemicals to address intestinal-related diseases.

Development of Spray-Dried Cyclodextrin-Based Pediatric Anti-HIV Formulations

The human immunodeficiency virus (HIV) impacts up to 37 million people globally, of which 1.8 million are children. To date, there is no cure for HIV, although treatment options such as antiretroviral therapy (ART) are available. ART, which involves a patient taking a combination of antiretrovirals, is being used to treat HIV clinically. Despite the effectiveness of ART, there is currently no palatable pediatric formulation to treat HIV in children, which has hindered patient compliance and overall treatment efficacy. In addition, anti-HIV therapeutics are often poorly water-soluble, and hence have poor bioavailability. In the present study, we developed a pediatric-friendly formulation for anti-HIV therapeutics with improved dissolution characteristics of the therapeutic agents. Lopinavir (LPV) and ritonavir (RTV), available as FDA-approved fixed-dose combination products, were chosen as model ART drugs, and the formulation and processing parameters of spray-dried cyclodextrin (CD)-based LPV and RTV complexes were studied. Results showed that the spray-dried complexes exhibited enhanced dissolution profiles in comparison to pure drugs, particularly spray-dried β-CD complexes, which showed the most favorable dissolution profiles. This current formulation with enhanced dissolution and taste-masking ability through the use of cyclodextrin has the potential to address the unmet need for the development of suitable pediatric formulations.

Biocompatible Polymers Combined with Cyclodextrins: Fascinating Materials for Drug Delivery Applications

Cyclodextrins (CD) are a group of cyclic oligosaccharides with a cavity/specific structure that enables to form inclusion complexes (IC) with a variety of molecules through non-covalent host-guest interactions. By an elegant combination of CD with biocompatible, synthetic and natural polymers, different types of universal drug delivery systems with dynamic/reversible properties have been generated. This review presents the design of nano- and micro-carriers, hydrogels, and fibres based on the polymer/CD supramolecular systems highlighting their possible biomedical applications. Application of the most prominent hydrophobic aliphatic polyesters that exhibit biodegradability, represented by polylactide and polycaprolactone, is described first. Subsequently, particular attention is focused on materials obtained from hydrophilic polyethylene oxide. Moreover, examples are also presented for grafting of CD on polysaccharides. In summary, we show the application of host-guest interactions in multi-component functional biomaterials for controlled drug delivery.

Cyclodextrins: Emerging Medicines of the New Millennium

Cyclodextrins, since their discovery in the late 19th century, were mainly regarded as excipients. Nevertheless, developments in cyclodextrin research have shown that some of these hosts can capture and include biomolecules, highlighting fatty acids and cholesterol, which implies that they are not inert and that their action may be used in specific medicinal purposes. The present review, centered on literature reports from the year 2000 until the present day, presents a comprehensive description of the known biological activities of cyclodextrins and their implications for medicinal applications. The paper is divided into two main sections, one devoted to the properties and applications of cyclodextrins as active pharmaceutical ingredients in a variety of pathologies, from infectious ailments to cardiovascular dysfunctions and metabolic diseases. The second section is dedicated to the use of cyclodextrins in a range of biomedical technologies.

Synthesis of the Anionic Hydroxypropyl-β-cyclodextrin:Poly(decamethylenephosphate) Polyrotaxane and Evaluation of its Cholesterol Efflux Potential in Niemann-Pick C1 Cells

Niemann-Pick type C disease (NPC) is a lysosomal storage disease that is characterized by a progressive accumulation of unesterified cholesterol in the lysosomes leading to organ damage from cell dysfunction. Hydroxypropyl-β-cyclodextrin (HP-β-CD) is an attractive drug candidate for treating NPC, as it diminishes cholesterol accumulation in NPC cells. Systemic HP-β-CD treatment, however, is limited by rapid renal clearance. We designed a new anionic HP-β-CD polyrotaxane to act as a slow release formulation based on a polyalkylene phosphate core to improve the pharmacokinetics. The polyalkylene phosphate comprises hydrophobic decamethylene spacers linked by biodegradable anionic phosphodiester bonds. HP-β-CD was threaded onto this polymer first and α-CD afterwards to prevent burst release of the threaded HP-β-CD. Our findings show that HP-β-CD was slowly released from the watersoluble polyrotaxane over a 30 days period. The polyrotaxane provided persistently diminished cholesterol levels in NPC1 cells by 20% relative to untreated cells. These results demonstrate the therapeutic potential of this novel HP-β-CD polyrotaxane for the mobilization of aberrantly stored cholesterol in NPC1 cells.

Use of Cyclodextrins in Anticancer Photodynamic Therapy Treatment

Photodynamic therapy (PDT) is mainly used to destroy cancerous cells; it combines the action of three components: a photoactivatable molecule or photosensitizer (PS), the light of an appropriate wavelength, and naturally occurring molecular oxygen. After light excitation of the PS, the excited PS then reacts with molecular oxygen to produce reactive oxygen species (ROS), leading to cellular damage. One of the drawbacks of PSs is their lack of solubility in water and body tissue fluids, thereby causing low bioavailability, drug-delivery efficiency, therapeutic efficacy, and ROS production. To improve the water-solubility and/or drug delivery of PSs, using cyclodextrins (CDs) is an interesting strategy. This review describes the in vitro or/and in vivo use of natural and derived CDs to improve antitumoral PDT efficiency in aqueous media. To achieve these goals, three types of binding modes of PSs with CDs are developed: non-covalent CD⁻PS inclusion complexes, covalent CD⁻PS conjugates, and CD⁻PS nanoassemblies. This review is divided into three parts: (1) non-covalent CD-PS inclusion complexes, covalent CD⁻PS conjugates, and CD⁻PS nanoassemblies, (2) incorporating CD⁻PS systems into hybrid nanoparticles (NPs) using up-converting or other types of NPs, and (3) CDs with fullerenes as PSs.

Cyclodextrin-containing hydrogels as an intraocular lens for sustained drug release

To improve the efficacy of anti-inflammatory factors in patients who undergo cataract surgery, poly(2-hydroxyethyl methacrylate-co-methyl methacrylate) (p(HEMA-co-MMA)) hydrogels containing β-cyclodextrin (β-CD) (pHEMA/MMA/β-CD) were designed and prepared as intraocular lens (IOLs) biomaterials that could be loaded with and achieve the sustained release of dexamethasone. A series of pHEMA/MMA/β-CD copolymers containing different ratios of β-CD (range, 2.77 to 10.24 wt.%) were obtained using thermal polymerization. The polymers had high transmittance at visible wavelengths and good biocompatibility with mouse connective tissue fibroblasts. Drug loading and release studies demonstrated that introducing β-CD into hydrogels increased loading efficiency and achieved the sustained release of the drug. Administering β-CD via hydrogels increased the equilibrium swelling ratio, elastic modulus and tensile strength. In addition, β-CD increased the hydrophilicity of the hydrogels, resulting in a lower water contact angle and higher cellular adhesion to the hydrogels. In summary, pHEMA/MMA/β-CD hydrogels show great potential as IOL biomaterials that are capable of maintaining the sustained release of anti-inflammatory drugs after cataract surgery.

The Potential of Cyclodextrins as Novel Active Pharmaceutical Ingredients: A Short Overview

Cyclodextrins (CDs) are cyclic oligosaccharides of natural origin that were discovered more than 100 years ago. The peculiar cone-like conformation of the sugar ring, expressing a lipophilic cavity and a hydrophilic external surface, allows these substances to spontaneously complex poorly soluble compounds in an aqueous environment. For more than 50 years, these substances have found applicability in the pharmaceutical and food industries as solubilizing agents for poorly soluble chemical entities. Nowadays, several research groups all over the world are investigating their potential as active pharmaceutical ingredients (APIs) for the treatment of several illnesses (e.g., hypercholesterolemia, cancer, Niemann-Pick Type C disease). The aim of this review is to briefly retrace cyclodextrins’ legacy as complexing agents and describe the current and future prospects of this class of chemical entities in pharmaceutics as new APIs.

Silicon(IV) Phthalocyanine-Decorated Cyclodextrin Vesicles as a Self-Assembled Phototherapeutic Agent against MRSA

The host-guest complexation of a tailored Si(IV) phthalocyanine with supramolecular β-cyclodextrin vesicles (CDV) was studied, revealing a reduced aggregation of the photoactive center upon binding to the CDV, even in aqueous environments. For this purpose, a photosensitizing unit axially decorated with one adamantyl group and one pyridinium moiety on the other side was obtained by two successive click reactions on a bis-azido-functionalized derivative of Si(IV) phthalocyanine. To evaluate its potential as a photosensitizer against antibiotic-resistant bacteria, comparative studies of the photophysical properties including absorption and emission spectroscopy, lifetimes as well as fluorescence and singlet oxygen quantum yields were determined for the Si(IV) phthalocyanine alone and upon self-assembly on the CDV surface. In vitro phototoxicity against the methicillin-resistant Staphylococcus aureus (MRSA) USA300 was evaluated, showing an almost complete inactivation.

Weight Maintenance with Litramine (IQP-G-002AS): A 24-Week Double-Blind, Randomized, Placebo-Controlled Study

BACKGROUND

Litramine (IQP-G-002AS) was shown to be effective and safe for weight loss in overweight and obese subjects. However, long-term effectiveness on maintenance of body weight loss has yet to be ascertained.

OBJECTIVE

To assess effect of Litramine on maintenance of body weight loss.

METHODS

A double-blind, randomised, placebo-controlled trial on overweight and obese patients was conducted over two sites in Germany for 24 weeks. Subjects with documented previous weight loss of 3% over the last 3-6 months were randomised to groups given either Litramine (3 g/day) or a matching placebo. Primary endpoints were difference of mean body weight (kg) between baseline and end of study and maintenance of initially lost body weight in verum group, where maintenance is defined as ≤1% weight gain.

RESULTS

Subjects who were taking Litramine lost significantly more body weight compared to the subjects taking placebo who gained weight instead (-0.62 ± 1.55 kg versus 1.62 ± 1.48 kg, p < 0.001). More importantly, 92% of subjects in Litramine group were able to maintain their body weight after initial weight loss, versus 25% in placebo group. No serious adverse events were reported throughout.

CONCLUSION

Litramine is effective and safe for long-term body weight maintenance. Trial Registration. This trial is registered with Clinicaltrials.gov identifier: NCT01505387.

Cyclodextrin protects podocytes in diabetic kidney disease

Diabetic kidney disease (DKD) remains the most common cause of end-stage kidney disease despite multifactorial intervention. We demonstrated that increased cholesterol in association with downregulation of ATP-binding cassette transporter ABCA1 occurs in normal human podocytes exposed to the sera of patients with type 1 diabetes and albuminuria (DKD(+)) when compared with diabetic patients with normoalbuminuria (DKD(-)) and similar duration of diabetes and lipid profile. Glomerular downregulation of ABCA1 was confirmed in biopsies from patients with early DKD (n = 70) when compared with normal living donors (n = 32). Induction of cholesterol efflux with cyclodextrin (CD) but not inhibition of cholesterol synthesis with simvastatin prevented podocyte injury observed in vitro after exposure to patient sera. Subcutaneous administration of CD to diabetic BTBR (black and tan, brachiuric) ob/ob mice was safe and reduced albuminuria, mesangial expansion, kidney weight, and cortical cholesterol content. This was followed by an improvement of fasting insulin, blood glucose, body weight, and glucose tolerance in vivo and improved glucose-stimulated insulin release in human islets in vitro. Our data suggest that impaired reverse cholesterol transport characterizes clinical and experimental DKD and negatively influences podocyte function. Treatment with CD is safe and effective in preserving podocyte function in vitro and in vivo and may improve the metabolic control of diabetes.

Cyclodextrins inhibit replication of scrapie prion protein in cell culture

Prion diseases are fatal neurodegenerative disorders that are caused by the conversion of a normal host-encoded protein, PrP(C), to an abnormal, disease-causing form, PrP(Sc). This paper reports that cyclodextrins have the ability to reduce the pathogenic isoform of the prion protein PrP(Sc) to undetectable levels in scrapie-infected neuroblastoma cells. Beta-cyclodextrin removed PrP(Sc) from the cells at a concentration of 500 microM following 2 weeks of treatment. Structure activity studies revealed that antiprion activity was dependent on the size of the cyclodextrin. The half-maximal inhibitory concentration (IC(50)) for beta-cyclodextrin was 75 microM, whereas alpha-cyclodextrin, which possessed less antiprion activity, had an IC(50) of 750 microM. This report presents cyclodextrins as a new class of antiprion compound. For decades, the pharmaceutical industry has successfully used cyclodextrins for their complex-forming ability; this ability is due to the structural orientation of the glucopyranose units, which generate a hydrophobic cavity that can facilitate the encapsulation of hydrophobic moieties. Consequently, cyclodextrins could be ideal candidates for the treatment of prion diseases.

Update for nurse anesthetists--part 3--cyclodextrin introduction to anesthesia practice: form, function, and application

Cyclodextrins, some of the select molecules exhibiting properties that are beneficial across multiple industries, are naturally occurring cyclical oligosaccharides with a lipophilic inner cavity and a hydrophilic exterior. These characteristics enable cyclodextrins to surround and bind lipophilic molecules while maintaining aqueous solubility. Agrochemistry, analytical chemistry, food, nutraceutical, and pharmaceutical industries have benefited and continue to benefit from these unique molecular properties. Though known and studied for more than 100 years, cyclodextrins have only recently been explored for specific application to anesthesia. Numerous studies exploring cyclodextrin-improved anesthetic delivery are underway. This new class of enabling molecules will enter the anesthetic arena and will require an understanding of their form, function, and application. This knowledge will facilitate anesthesia providers' optimal use of these unique molecules and the safety and efficacy associated with them.

Selective relaxant binding agents for reversal of neuromuscular blockade

Traditionally, reversal of neuromuscular blockade during anaesthesia was achieved by increasing the acetylcholine concentration in the neuromuscular junction using acetylcholinesterase inhibitors. However, this is ineffective against profound blockade. Furthermore, the increase in acetylcholine level is not limited to the neuromuscular junction, resulting in unwanted side effects requiring co-treatment with muscarinic antagonists. Selective relaxant binding agents offer a new approach for the reversal of neuromuscular blockade: encapsulation of the neuromuscular blocking agent, resulting in inactivation. As part of this new approach, cyclodextrin molecules have been designed that selectively encapsulate steroidal neuromuscular blocking agents. Both animal and human experiments have demonstrated that fast, effective and complete recovery from both normal and profound neuromuscular blockade is now possible. Furthermore, these cyclodextrin derivatives do not have the unwanted side effects of acetylcholinesterase inhibitors.

Oral delivery of meglumine antimoniate-beta-cyclodextrin complex for treatment of leishmaniasis

The need for daily parenteral administration represents one of the most serious limitations in the clinical use of pentavalent antimonials against leishmaniasis. In this work, we investigated the ability of beta-cyclodextrin to enhance the oral absorption of antimony and to promote the oral efficacy of meglumine antimoniate against experimental cutaneous leishmaniasis. The occurrence of interactions between beta-cyclodextrin and meglumine antimoniate was demonstrated through the changes induced in the spin lattice relaxation times of protons in both compounds. When free and complexed meglumine antimoniate were given orally to Swiss mice, plasma antimony levels were found to be about three times higher for the meglumine antimoniate-beta-cyclodextrin complex than for the free drug. Antileishmanial efficacy was evaluated in BALB/c mice experimentally infected with Leishmania amazonensis. Animals treated daily with the complex (32 mg of Sb/kg of body weight) by the oral route developed significantly smaller lesions than those treated with meglumine antimoniate (120 mg of Sb/kg) and control animals (treated with saline). The effectiveness of the complex given orally was equivalent to that of meglumine antimoniate given intraperitoneally at a twofold-higher antimony dose. The antileishmanial efficacy of the complex was confirmed by the significantly lower parasite load in the lesions of treated animals than in saline-treated controls. This work reports for the first time the effectiveness of an oral formulation for pentavalent antimonials.

Anticryptosporidial Activity of Furan Derivative G1 and Its Inclusion Complex with Beta-Cyclodextrin

The capacity of beta-cyclodextrin (betaCD) to form a complex with a new furanic derivative, G1, was investigated. Interactions of the drug and betaCD in solution and in the solid state were studied using phase solubility techniques, thermal methods, X-ray, and IR spectroscopy. Preparation of a kneaded mix of G1/betaCD increased both the aqueous solubility and the dissolution rate of the furan derivative. The anticryptosporidial efficacies of the drug and of the inclusion complex were evaluated using a suckling murine model. Oral administration of G1 considerably decreased the intensity of the infection, but betaCD showed similar anticryptosporidial activity to that of the betaCD-G1 complex and higher activity than G1 alone.

In vitro and in vivo efficacy of alpha-cyclodextrin for treatment of experimental cryptosporidiosis

The efficacy of alpha-cyclodextrin against infection by Cryptosporidium parvum was evaluated using in vitro and in vivo models. Cyclodextrins are water-soluble cyclic hexamers of glucose units with hydrophobic cavities capable of solubilizing lipophiles and are widely used as drug excipients in the pharmaceutical industry. The viability of purified C. parvum oocysts, exposed for 30, 60, 90, 120 min and 24h to different concentrations of alpha-cyclodextrin (2.5, 5, 7.5, 10, 12.5 and 15%), was evaluated by inclusion or exclusion of two fluorogenic vital dyes and by an excystation technique. Preventive and curative efficacies against cryptosporidial infections, at different doses (2.5 and 5%) and regimes of administration of alpha-cyclodextrin, were determined in an experimental neonatal mice model. Results of the viability assay showed a decrease in oocyst viability that was associated with an increase in exposure time, for each of the concentrations used. Moreover, a high proportion of nonviable oocysts (81%) was observed when C. parvum oocysts were exposed to alpha-cyclodextrin (2.5%) for 24h. The intensity of infection, determined 7 days post-inoculation by examination of intestinal homogenates, was significantly lower (P<0.05) than in the control litters, for all the assays carried out with alpha-cyclodextrin. Only 38.8% of the animals became infected when the alpha-cyclodextrin solution (5%) was administered 2h before inoculated oocysts, and every 24h at 1 and 2 days post-inoculation.

Efficacy and tolerability of piroxicam-beta-cyclodextrin in the outpatient management of chronic back pain

BACKGROUND

Piroxicam-beta-cyclodextrin (PBC) is the first nonsteroidal anti-inflammatory drug (NSAID), in which the active substance is complexed with the cyclic oligosaccharide cyclodextrin, which acts as an artificial receptor. This complex allows single molecules of the NSAID to be released adjacent to the gastrointestinal mucosa, instead of crystals. Since the piroxicam is immediately bioavailable in this formulation, the onset of action is similar to that of a parenteral drug. Since the time contact with gastric mucosa is reduced, the risk of direct-contact gastric irritation is also reduced. There is good evidence that PBC is beneficial in managing acute non-specific back pain (BP) but sufficient evidence on chronic BP is lacking.

METHODS

Thirty-one eligible patients aged 18-85 years, resistant to previous therapy with different NSAIDs, were treated with PBC 20 mg once daily in a 40-day open-label noncomparative study. The patients experienced chronic BP defined as pain between the occipital region and gluteal fold, lasting for at least 6 weeks but not more than 6 months. Efficacy was assessed by changes in pain intensity, paravertebral tonus, functional impairment and morning stiffness using a 4-point numerical rating scale. Patients also self-assessed nocturnal and diurnal pain using the visual analogue scale. Tolerability was assessed by adverse events and routine laboratory evaluations. Global assessment of efficacy and tolerability by physician and patients was performed at the last visit.

RESULTS

Using intention-to-treat analysis, all efficacy assessments demonstrated statistically significant improvements over baseline at each follow-up. 90.3% of the patients evaluated the efficacy of PBC as improved or greatly improved, and investigators rated the treatment as improved or greatly improved in 87.1% of patients. Remission was achieved in 19.3% of the patients. Tolerability was also rated highly, with 83.9% of the patients characterizing PBC treatment as good or very good, and the investigators rated the treatment as good or excellent in 87.1% of the patients. Drug related adverse events were reported in 9.7% of patients and prompted discontinuation of the study medication in 3.2% of patients. No serious adverse events were reported.

CONCLUSION

These results suggest that the newly developed dosage form of piroxicam is effective and well tolerated in the treatment of patients with chronic BP. Thus, PBC, may be an important new treatment option in this condition. (Tab. 3, Fig. 3, Ref. 36.).

A mucoadhesive, cyclodextrin-based vaginal cream formulation of itraconazole

The development of vaginal medications, especially antifungal medications, requires that the drug is solubilized as well as retained at or near the mucosa for sufficient periods of time to ensure adequate bioavailability. Itraconazole is a broad-spectrum antifungal agent, which has been used for some time orally and intravenously but for which a vaginal formulation has not yet been developed. We present here a novel itraconazole formulation intended for vaginal use based on hydroxypropyl-beta-cyclodextrin (HPbetaCD), a functional excipient that increases drug solubility and generates a mucoadhesive system in the presence of other ingredients. An aqueous phase was prepared by solubilizing itraconazole with HCl in the presence of propylene glycol and then adding an aqueous solution of HPbetaCD. After pH adjustment, the itraconazole/HPbetaCD solution was added to the oil phase (paraffin oil, trihydroxystearate, and cetyl dimethicon copolyol) and the desired cream containing 1%, 2%, and 2.5% drug obtained by homogenization. Primary irritation studies and subchronic toxicity studies using a rabbit vaginal model indicated that the formulation was safe, well tolerated, and retained in the vaginal space. Clinical investigations indicated that application of 5 g of a 2% cream was very well tolerated and itraconazole was not systemically absorbed. Additional studies in women found that the itraconazole cream was highly effective in reducing or eliminating fungal cultures with few adverse effects. These studies suggested that an HPbetaCD-based, emulsified wax cream formulation was a useful and effective dosage form for treating vaginal candidiasis.

Evaluation of efficacy of nizer versus nimesulide tablets in otitis media

An evaluation of clinical efficacy of nizer versus nimesulide tablets was undertaken in 118 patients suffering from otitis media. Nizer demonstrated rapid and powerful analgesic and antipyretic effects compared to plain nimesulide, without additional side effects.

Silybin-beta-cyclodextrin in the treatment of patients with diabetes mellitus and alcoholic liver disease. Efficacy study of a new preparation of an anti-oxidant agent

BACKGROUND AND AIMS

In patients with non-insulin dependent diabetes mellitus (T2DM) and associated chronic liver disease, plasma levels of glucose, insulin and triglycerides are high, lipid peroxidation is increased and natural antioxidant reserves are reduced. Thus, we hypothesised that the re-balancing of cell redox levels and amelioration of liver function could result in a better glucose and lipid metabolism. To study this, we assessed the effect of a new oral formulation of an antioxidant agent - silybin-beta-cyclodextrin (named IBI/S) - in patients with chronic alcoholic liver disease and concomitant T2DM.

METHODS

Sixty outpatients were enrolled in a three-centre, double blind, randomised, IBI/S vs placebo study. Forty-two (21 in the group IBI/S - 135 mg/d silybin per os - and 21 in the placebo group) concluded the 6-month treatment period. The efficacy parameters included fasting and mean daily plasma glucose levels, glycosylated hemoglobin (HbA1c), basal, stimulated C-peptide and insulin levels, total-, HDL-cholesterol and triglycerides levels in addition to conventional liver function tests. Insulin sensitivity was estimated by HOMA-IR. Malondialdehyde (MDA) was also measured before and after treatment as an index of oxidative stress.

RESULTS

Fasting blood glucose levels, which were similar at baseline in IBI/S group and in the placebo group (173.9 mg/dl and 177.1 mg/dl, respectively), decreased to 148.4 mg/dl (-14.7% vs baseline; p = 0.03) in the IBI/S group while they were virtually unchanged in the placebo group. The comparison between the groups at mo 6 (T6) also showed a significant reduction of glucose levels in the IBI/S group (p = 0.03). The same trend was observed in mean daily blood glucose levels, HbA1c and HOMA-IR, although differences were not significant. Basal and stimulated C-peptide values showed that only a few changes had occured in both groups. Such results indicate that insulin secretion was virtually unaffected, as confirmed also by the insulinemia data. Plasma triglycerides concentrations dropped from a baseline value of 186 mg/dl to 111 mg/dl (T6) in the IBI/S group, with significant differences at all instances with respect to baseline values. By contrast, triglycerides increased from 159 mg/dl at entry to 185 mg/dl (T6) in the placebo group. The difference between the groups at T6 was highly significant (p < 0.01). Total and HDL cholesterol as well as liver function tests did not change significantly during the study in both groups. MDA decreased significantly only in the group receiving IBI/S. No clinically relevant side effects were observed in either group.

CONCLUSIONS

Oral administration silybin-beta-cyclodextrin in patients with T2DM and compensated chronic alcoholic liver disease causes a significant decrease in both glucose and triglyceride plasma levels. These effects may be due to the recovery of energy substrates, consistent with a reduced lipid peroxidation and an improved insulin activity.

Safety, pharmacokinetics, and pharmacodynamics of cyclodextrin itraconazole in pediatric patients with oropharyngeal candidiasis

The safety, pharmacokinetics, and pharmacodynamics of cyclodextrin itraconazole (CD-ITRA) oral suspension were investigated in an open sequential dose escalation study with 26 human immunodeficiency virus (HIV)-infected children and adolescents (5 to 18 years old; mean CD4(+)-cell count, 128/microl) with oropharyngeal candidiasis (OPC). Patients received CD-ITRA at either 2.5 mg/kg of body weight once a day (QD) or 2.5 mg/kg twice a day (BID) for a total of 15 days. Pharmacokinetic sampling was performed after the first dose and for up to 120 h after the last dose, and antifungal efficacy was evaluated by standardized scoring of the oropharynx. Apart from mild to moderate gastrointestinal disturbances in three patients (11.5%), CD-ITRA was well tolerated. Two patients (7.6%) discontinued treatment prematurely due to study drug-related adverse events. After 15 days of treatment, the peak concentration of drug in plasma (C(max)), the area under the plasma concentration-time curve (AUC) from 0 to 24 h (AUC(0-24)), the concentration in plasma at the end of the dosing interval (predose) (C(min)), and the terminal half-life of itraconazole (ITRA) were (means and standard deviations) 0.604 +/- 0.53 microg/ml, 6.80 +/- 7.4 microg. h/ml, 0.192 +/- 0.06 microg/ml, and 56.48 +/- 44 h, respectively, for the QD regimen and 1.340 +/- 0.75 microg/ml, 23.04 +/- 14.5 microg. h/ml, 0.782 +/- 0.19 microg/ml, and 104.22 +/- 94 h, respectively, for the BID regimen. The mean AUC-based accumulation factors for ITRA on day 15 were 4.14 +/- 0.9 and 3.53 +/- 0.6, respectively. A comparison of the dose-normalized median AUC of the two dosage regimens revealed a trend toward nonlinear drug disposition (P = 0.05). The mean metabolic ratios (AUC of hydroxyitraconazole/AUC of ITRA) at day 15 were 1.96 +/- 0.1 for the QD regimen and 1.29 +/- 0.2 for the BID regimen, respectively (P < 0.05). The OPC score (range, 0 to 13) for all 26 patients decreased from a mean of 7.46 +/- 0.8 at baseline to 2.8 +/- 0.7 at the end of therapy (P < 0.001), demonstrating antifungal efficacy in this setting. The relationships among C(max), C(min), AUC(0-12), C(max)/MIC, C(min)/MIC, AUC(0-12)/MIC, time during the dosing interval when the plasma drug concentrations were above the MIC for the infecting isolate, and the residual OPC score at day 15 for the entire study population fit inhibitory effect pharmacodynamic models (r, 0.595 to 0.421; P, <0.01 to <0.05). All patients with fluconazole-resistant isolates responded to treatment with CD-ITRA; however, there was no clear correlation between the MIC of ITRA and response to therapy. In conclusion, CD-ITRA was well tolerated and efficacious for the treatment of OPC in HIV-infected pediatric patients. Pharmacodynamic modeling revealed significant correlations between plasma drug concentrations and antifungal efficacy. Based on this documented safety and efficacy, a dosage of 2.5 mg/kg BID can be recommended for the treatment of OPC in pediatric patients > or =5 years old.

Effects of canrenone on myocardial reactive fibrosis in a rat model of postinfarction heart failure

BACKGROUND

Spironolactone reduces overall mortality by 30% in advanced congestive heart failure. Nevertheless, few data are available with regard to the effects of mineral corticoid inhibition in postinfarction heart failure.

MATERIALS AND METHODS

Experimental myocardial infarction was induced by left coronary ligation in 70 male rats with body weights ranging from 180 to 200 gr. The day after surgery, animals were randomized to either placebo or canrenone-gamma-cyclodestrin 8 mg/kg/die or canrenone-gamma-cyclodestrin 18 mg/kg/die. Twelve animals served as the control group. After two weeks, the rats underwent closed chest left ventricular catheterization. The heart was the rapidly excised for subsequent histological analysis.

RESULTS

Compared with controls, infarcted rats had reduced left ventricular systolic pressures (-6%) and higher left ventricular end-diastolic pressures (+600%), associated with a marked increase of mean collagen fraction (+446%) and perivascular fibrosis (+72%). Compared with placebo-infarcted rats, in the group treated with high canrenone dose there was a significant reduction of left ventricular systolic and end-diastolic pressures (-6.5% and -23%, respectively) and an attenuation of interstitial and perivascular fibrosis (-47% and -34%, respectively). The low-dose canrenone group did not show differences compared with the placebo infarcted rats, except for a slight reduction of mean collagen fraction (-21%).

CONCLUSIONS

Canrenone attenuates LV interstitial remodeling and reduces filling pressures in rats with postinfarction heart failure.

[Glomerular morphologic protection after acute ischemia through the administration of Surgiran: (PGE1 and Alfadex, glucose cyclic oligomer). Morphometric study]

OBJECTIVE

To quantify the morphologic protection of PGE1 on renal glomerulus following normothermic acute renal ischemia.

METHODS

This experimental study was carried out in 48 adult male Wistar rats. A simple right nephrectomy was performed in all rats. The rats were divided into two groups: one group was perfused with PGE1 and the other group with saline solution immediately after acute renal ischemia, which was produced by non-traumatic vascular clamping. The ischemia times were 15 and 60 minutes. The recovery period ranged from 24 hours to 7 days. After this period the animals were anesthetized and sacrificed. Histological and morphometric analyses of the right kidneys of the control group and the left kidneys of the study group were performed.

RESULTS

The mortality was 31% (18.5% for the group perfused with PGE1 and 11.4% for the group perfused with saline solution). Kidneys of rats perfused with saline solution weighed more than the kidneys of rats perfused with PGE1 (1.771 +/- 0.455 and 1.55 +/- 0.34, respectively). Acute tubular necrosis was observed after 60 minutes' ischemia and was more evident in the saline than in the PGE1 group. The morphometric study showed no significant differences between the control (normal) and the PGE1 group for glomerular diameter (p < or = 0.101), sphericity factor (p < or = 0.239), glomerular perimeter (p < or = 0.092) and glomerular volume (p < or = 0.059). However, significant differences were found between the control and the saline perfusion group for area (p < or = 0.000), diameter (p < or = 0.000), perimeter (p < or = 0.000) and volume (p < or = 0.000).

CONCLUSIONS

Kidney weight after ischemia increased more in the saline than in the PGE1-treated group since the edema in the renal parenchyma is attenuated by the anti-inflammatory and cytoprotective effects of PGE1. The morphometric study showed that in comparison to saline, PGE1 exerts a cytoprotective effect, although it is not considerable.

Efficacy of beta-cyclodextrin against experimental cryptosporidiosis in neonatal lambs

The efficacy of beta-cyclodextrin against experimental Cryptosporidium parvum infection was evaluated in neonatal lambs. The animals were treated by oral administration of the drug at 1 g/kg of body weight during 3 consecutive days. Preventive treatment was started within 1 day of birth, and therapeutic treatment was initiated at the onset of diarrhea following confirmation of infection. Disease development and drug efficacy were evaluated by monitoring the presence or absence of diarrhea and oocyst shedding from birth until 30 days of age. Weight gains at 15 and 30 days of age were also recorded. Beta-cyclodextrin was highly effective as a prophylactic treatment; 1 animal did not acquire the infection, diarrhea was prevented in infected animals, and there was a considerable decrease in oocyst shedding. The therapeutic treatment was effective in decreasing the severity of diarrhea and the duration of oocyst shedding. The animals tolerated the drug well, and there was a significant increase in their body weights.

Cyclodextrins in the treatment of a mouse model of Niemann-Pick C disease

Niemann-Pick type C (NPC) is a neurodegenerative disorder characterized by greatly altered somatic cholesterol metabolism. The NPC1 gene has recently been cloned and shown to have sequence homology to other sterol-sensing proteins. We have used a mouse model with a disrupted npc1 gene to study the effects of the cholesterol-mobilizing compound, 2-hydroxypropyl-beta-cyclodextrins (HPBCD), on the clinical course of this disorder. Treatment with two HPBCDs, with varying levels of 2-hydroxypropyl substitution, had effects in delaying neurological symptoms and in decreasing liver cholesterol storage while a third HPBCD was without effect. The ameliorating effect was not improved by longer exposure times (commencement of exposure in utero), however, it is not known if there is transplacental transfer of HPBCDs. The combination of HPBCD with probucol or nifedipine (which have previously been shown to lower liver cholesterol in this animal model) markedly decreased liver storage of unesterified cholesterol without altering the depressed levels of esterified cholesterol. The slight effects of the HPBCDs on neurological symptoms may be partially due to their apparent non-permeation of the blood-brain barrier (BBB). This non-permeation was assayed with radioactive tracers and was also present in the mdr1a knockout mice which have greatly increased BBB permeability for many drugs. Intrathecal delivery of HPBCD by an Alzet osmotic minipump did not improve its efficacy in ameliorating neurological symptoms.

Evaluation of beta-cyclodextrin against natural infections of cryptosporidiosis in calves

The effectiveness of beta-cyclodextrin, excipient used in pharmaceutical industry, in the treatment of natural infection by Cryptosporidium parvum in suckling calves, was evaluated. Administration of the drug at a dose of 500 mg/kg body weight for 3 consecutive days from birth (prophylactically) or following confirmation of the infection (therapeutically) decreased the severity of diarrhoea and shortened the duration of oocyst shedding.

Treatment with beta-cyclodextrin of natural Cryptosporidium parvum infections in lambs under field conditions

Following the unexpected activity of the excipient beta-cyclodextrin against experimental infection by Cryptosporidium parvum in suckling mice, its efficacy in the prevention and treatment of natural infections in lambs was evaluated under field conditions. Fifty-three crossbred neonatal lambs were randomly selected for the study. Treatment consisted of oral administration of an aqueous suspension of beta-cyclodextrin at a dose of 500 mg/kg of body weight. To test prophylactic efficacy, the suspension was administered at 1, 2 and 3 days of age. To evaluate therapeutic efficacy, the suspension was administered on each of the 3 days following onset of diarrhoea. Infection was monitored by daily examination of faecal samples, from birth to 30 days. The criteria studied in evaluating efficacy were: oocyst shedding, the presence of diarrhoea, and weight gain at 15 and 30 days. In the group that received prophylactic treatment with beta-cyclodextrin, there were no mortalities and, compared with control lambs, there was a decrease in the number of animals infected, a longer prepatent period and notable reduction in the patent period and the duration of diarrhoea. Therapeutic treatment also reduced the patent period and the severity of diarrhoea. beta-cyclodextrin was well tolerated by all of the treated animals.

Inhibition of Cryptosporidium infection in mice treated with a cyclodextrin inclusion complex with diloxanide furoate

The efficacies of diloxanide furoate, beta-cyclodextrin and a cyclodextrin inclusion complex against Cryptosporidium parvum were evaluated in a suckling murine model. Efficacy was established by numbers of oocysts recovered from the intestinal tract of mice on day 7 postinfection. The level of infection in treated mice was significantly lower than in control mice and, surprisingly, the most efficacious treatment was beta-cyclodextrin, an excipient used in pharmaceutical technology.

Treatment of Raynaud's phenomenon with intravenous prostaglandin E1alpha-cyclodextrin improves endothelial cell injury in systemic sclerosis

OBJECTIVE

To evaluate the efficacy and safety of prostaglandin (PG) E1alpha-cyclodextrin for Raynaud's phenomenon (RP) secondary to systemic sclerosis (SSc) and its effect on variables of immune activation and endothelial injury in SSc such as tumor necrosis factor-alpha (TNF-alpha), soluble interleukin 2 receptor (sIL-2R), circulating intercellular adhesion molecule-1 (cICAM-1), von Willebrand factor (vWF), and tissue-type plasminogen activator (t-PA).

METHODS

We studied 36 women with SSc, 24 of them given three 60 microg intravenous PGE1alpha-cyclodextrin infusions on 5 consecutive days at 6 week intervals during the winter. RP symptoms and healing of digital lesions were evaluated. Twenty age matched healthy women were the controls. TNF-alpha, sIL-2R, cICAM-1, vWF, and t-PA were measured after the first and last infusion of PGEE1alpha-cyclodextrin and correlated with clinical features.

RESULTS

RP symptoms improved in 87% of the patients. The benefit of each 5 day cycle lasted 4 or more weeks in 75%. PGE1alpha-cyclodextrin reduced the daily frequency of RP symptoms by 20% (p < 0.05), 41% (p < 0.005), and 53% (p < 0.0005) from baseline after the 1st, 2nd, and 3rd infusions, respectively. The severity of the attacks was reduced to a limited degree. In 12 of the 14 patients with digital lesions, these healed completely. Ten patients had mild side effects during treatment (headache, increased intestinal motility, flushing). TNF-alpha, sIL-2R, cICAM-1, vWF, and t-PA plasma concentrations were significantly higher in patients with SSc than controls (p < 0.05, p < 0.001). TNF-alpha, sIL-2R, and cICAM-1 were higher in diffuse SSc and patients with lung involvement. The plasma levels of cICAM-1 and t-PA were significantly reduced after the 1st infusion of PGE1alpha-cyclodextrin (both p < 0.005) and further reduced after the last (p < 0.0005 and p < 0.005).

CONCLUSION

PGE1alpha-cyclodextrin reduces RP symptoms and plasma levels of the markers of endothelial injury in SSc, suggesting that an improvement of endothelial dysfunction contributes to its prolonged therapeutic effect.

Unexpected activity of beta-cyclodextrin against experimental infection by Cryptosporidium parvum

An unexpected activity of beta-cyclodextrin, an excipient used in pharmaceutical technology, was observed against Cryptosporidium parvum. The viability and infectivity of purified oocysts, exposed for 24 hr to beta-cyclodextrin (2.5% suspension), were evaluated by inclusion/exclusion of 2 fluorogenic vital dyes and a suckling murine model, respectively. Results of the viability assay showed a high proportion of nonviable oocysts (81.5%). The intensity of experimental infection, determined 7 days postinoculation by examination of intestinal homogenates, was significantly lower (P < 0.05) than in the control litters. The preventive and curative efficacies of beta-cyclodextrin suspension were also evaluated in experimentally infected neonatal mice. Infection was prevented when the suspension was administered 2 hr before inoculated oocysts and on days 1 and 2 postinoculation.

Methazolamide 1% in cyclodextrin solution lowers IOP in human ocular hypertension

PURPOSE

To formulate aqueous eye drops containing methazolamide 1% in cyclodextrin solution and to evaluate their effect on intraocular pressure (IOP) in a double-blind randomized trial in humans. Methazolamide, a carbonic anhydrase inhibitor (CAI), has been used in oral doses in the treatment of glaucoma but hitherto has not been successfully formulated in eye drops. In this study the effects of methazolamide are compared with those of dorzolamide (Trusopt).

METHODS

Methazolamide 1% was formulated in a 2-hydroxypropyl-beta-cyclodextrin with hydroxypropyl methylcellulose in aqueous solution. Eight persons with ocular hypertension were treated with the methazolamide-cyclodextrin eye drops and eight persons with dorzolamide (Trusopt), both groups at dosages of three times a day for 1 week. IOP was measured before treatment was begun and on days 1, 3, and 8 at 9 AM (peak) and 3 PM (trough).

RESULTS

After 1 week of treatment, the peak IOP in the methazolamide group had decreased from 24.4 +/- 2.1 mm Hg (mean +/- SD) to 21.0 +/- 2.0 mm Hg, which is a 14% pressure decrease (P: = 0.006). In the dorzolamide group, the peak IOP decreased from 23.3 +/- 2.1 mm Hg to 17.2 +/- 3.1 mm Hg, which is a 26% pressure decrease (P: < 0.001). On average, the IOP declined 3.4 +/- 1.8 mm Hg after methazolamide administration and 6.1 +/- 3.6 mm Hg after dorzolamide.

CONCLUSIONS

Through cyclodextrin complexation, it is possible to produce topically active methazolamide eye drops that lower IOP. This is the first double-blind clinical trial that demonstrates the efficacy of the classic CAIs in eye drop formulation.

Apolipoprotein A-I, cyclodextrins and liposomes as potential drugs for the reversal of atherosclerosis. A review

Several studies have revealed that high-density lipoprotein (HDL) is the most reliable predictor for susceptibility to cardiovascular disease. Since apolipoprotein A-I (apoA-I) is the major protein of HDL, it is worthwhile evaluating the potential of this protein to reduce the lipid burden of lesions observed in the clinic. Indeed, apoA-I is used extensively in cell culture to induce cholesterol efflux. However, while there is a large body of data emanating from in-vitro and cell-culture studies with apoA-I, little animal data and scant clinical trials examining the potential of this apolipoprotein to induce cholesterol (and other lipid) efflux exists. Importantly, the effects of oxysterols, such as 7-ketocholesterol (7KC), on cholesterol and other lipid efflux by apoA-I needs to be investigated in any attempt to utilise apoA-I as an agent to stimulate efflux of lipids. Lessons may be learnt from studies with other lipid acceptors such as cyclodextrins and phospholipid vesicles (PLVs, liposomes), by combination with other effluxing agents, by remodelling the protein structure of the apolipoprotein, or by altering the composition of the lipoprotein intended for administration in-vivo. Akin to any other drug, the usage of this apolipoprotein in a therapeutic context has to follow the traditional sequence of events, namely an evaluation of the biodistribution, safety and dose-response of the protein in animal trials in advance of clinical trials. Mass production of the apolipoprotein is now a simple process due to the advent of recombinant DNA technology. This review also considers the potential of cyclodextrins and PLVs for use in inducing reverse cholesterol transport in-vivo. Finally, the potential of cyclodextrins as delivery agents for nucleic acid-based constructs such as oligonucleotides and plasmids is discussed.

[Chronic diarrhea due to lymphocytic colitis treated with piroxicam beta cyclodextrin]

BACKGROUND

Lymphocytic colitis is a chronic diarrhea syndrome with no endoscopically detectable anomaly and histological colonic lesions.

CASE REPORT

A 52-year-old woman was hospitalized for chronic diarrhea. She experienced 10 to 30 liquid bowel movements per day. Symptoms had begun 8 days after taking piroxicam fl-cyclodextrin. Intraepithelial cell counts on rectum and colon endoscopic biopsies showed more than 20% lymphocytes, giving the diagnosis of lymphocytic colitis. The patient was given 5ASA 3 g/24 h. Symptoms regressed in less than one week.

DISCUSSION

Lymphocytic colitis is uncommon. The cause remains unknown but a secondary autoimmune mechanism triggered by drugs has been suggested. This case would implicate nonsteroidal antiinflammatory drugs. Certain authors have demonstrated that they can be involved in the development of collagen colitis.

Antilithiasic effect of beta-cyclodextrin in LPN hamster: comparison with cholestyramine

Beta-Cyclodextrin (BCD), a cyclic oligosaccharide that binds cholesterol and bile acids in vitro, has been previously shown to be an effective plasma cholesterol lowering agent in hamsters and domestic pigs. This study examined the effects of BCD as compared with cholestyramine on cholesterol and bile acid metabolism in the LPN hamster model model for cholesterol gallstones. The incidence of cholesterol gallstones was 65% in LPN hamsters fed the lithogenic diet, but decreased linearly with increasing amounts of BCD in the diet to be nil at a dose of 10% BCD. In gallbladder bile, cholesterol, phospholipid and chenodeoxycholate concentrations, hydrophobic and lithogenic indices were all significantly decreased by 10% BCD. Increases in bile acid synthesis (+110%), sterol 27-hydroxylase activity (+106%), and biliary cholate secretion (+140%) were also observed, whereas the biliary secretion of chenodeoxycholate decreased (-43%). The fecal output of chenodeoxycholate and cholate (plus derivatives) was increased by +147 and +64%, respectively, suggesting that BCD reduced the chenodeoxycholate intestinal absorption preferentially. Dietary cholestyramine decreased biliary bile acid concentration and secretion, but dramatically increased the fecal excretion of chenodeoxycholate and cholate plus their derivatives (+328 and +1940%, respectively). In contrast to BCD, the resin increased the lithogenic index in bile, induced black gallstones in 34% of hamsters, and stimulated markedly the activities of HMG-CoA reductase (+670%), sterol 27-hydroxylase (+310%), and cholesterol 7alpha-hydroxylase (+390%). Thus, beta-cyclodextrin (BCD) prevented cholesterol gallstone formation by decreasing specifically the reabsorption of chenodeoxycholate, stimulating its biosynthesis and favoring its fecal elimination. BCD had a milder effect on lipid metabolism than cholestyramine and does not predispose animals to black gallstones as cholestyramine does in this animal model.

Sulfolipo-cyclodextrin in squalane-in-water as a novel and safe vaccine adjuvant

Previously, we described synergistic adjuvanticity of combinations of synthetic sulfolipo(SL)-derivatives of polysaccharide (SL-polysaccharides) and squalane-in-water emulsions (squalane/W). In this paper, effects of type of polysaccharide and nature of oil on adjuvanticity, reactogenicity and stability are described. SL-derivatives of the following polysaccharides were synthesised: synthetic polysucroses with weight-average molecular weight (MW) of 400,000 (Ficoll400), 70,000 (Ficoll70) and 39,000 Da (Ficoll39), polyfructose of 5,000 Da (inulin), linear polyglucose of 1,200 Da (maltodextrin) and cyclic polyglucose of 1,135 Da (beta-cyclodextrin). The number of sulphate groups per monosaccharide of the different SL-polysaccharides varied between 0.15 and 0.23 and the number of lipid groups per monosaccharide between 1.15 and 1.29. Adjuvant formulations were prepared by incorporating these SL-polysaccharides into oil-in-water emulsions of either squalane, hexadecane, soya oil or mineral oil. Adjuvanticity of the formulations obtained for humoral responses to inactivated pseudorabies virus (PRV) and inactivated influenza virus strains A/Swine (A/Swine) and MRC-11 (MRC-11) in pigs and MRC-11 and ovalbumin (OVA) in mice depended on the type of oil (squalane = mineral oil > hexadecane = soya oil) but not on the type of polysaccharide backbone of the SL-derivative. Reactogenicity assessed by local swelling in mice decreased with decreasing MW (SL-Ficoll400 = Ficoll70 = Ficoll39 > SL-inulin = SL-maltodextrin > SL-cyclodextrin) when combined with squalane and decreased with the type of oil in the following order: squalane > mineral oil > hexadecane > soya oil when combined with SL-Ficoll400. Stability of the SL-polysaccharide/squalane/W emulsions at elevated temperature increased with decreasing MW of the SL-polysaccharide (SL-Ficoll400 < SL-Ficoll70 = SL-Ficoll39 < SL-inulin = SL-maltodextrin = SL-cyclodextrin). SL-cyclodextrin/squalane/W remained stable for > 2.5 years at 4 degrees C, > 18 weeks at 37 degrees C and > 10 days at 60 degrees C. We concluded that reactogenicity and stability but not adjuvanticity of SL-polysaccharide/squalane/W formulations depended on the MW of SL-polysaccharide and that SL-cyclodextrin/squalane/W is a promising non-mineral oil adjuvant as it combines strong adjuvanticity (i.e. better than the mineral oil-based adjuvant presently applied) with low reactogenicity and good stability.

Development of a toxin-binding agent as a treatment for tunicaminyluracil toxicity: protection against tunicamycin poisoning of sheep

OBJECTIVE

To assess the ability of certain derivatives of beta-cyclodextrin to treat sheep affected by tunicaminyluracil toxicity, using tunicamycin poisoning as a model system.

DESIGN

Controlled treatment trial.

ANIMALS

One hundred and sixty Merino wethers were used in the studies.

PROCEDURE

Groups of sheep were experimentally poisoned with tunicamycin. Derivatives of beta-cyclodextrin, with or without magnesium sulphate and magnesium gluconate, were administered to treatment groups daily for 2 to 3 days. Treatment groups were compared with untreated groups in terms of survival.

RESULTS

A significant increase in survival was observed following treatment of tunicamycin-affected sheep with hydroxypropyl-beta-cyclodextrin (HP beta-CD) and magnesium sulphate in solution (P < 0.05). In subsequent trials, formulation of the cyclodextrin in the form of a magnesium gluconate gel suspension demonstrated significant protection (P < 0.01) and was equally as effective as the cyclodextrin in solution, but required half the frequency of administration, even when the treatment was not commenced until 24 h after the final toxin dose. Beta-cyclodextrin-epichlorohydrin copolymer also improved the survival rate. After toxin administration, the sheep lost significantly less weight if treatment with HP beta-CD was commenced early (P < 0.001).

CONCLUSION

Protection studies using these two beta-cyclodextrin derivatives suggest that they may be effective in increasing the survival of sheep poisoned by tunicamycin and warrant further testing in field outbreaks of annual ryegrass toxicity.

[Analysis of costs and results of prostaglandin (PGE1 alpha-cyclodestrin) therapy of peripheral arterial diseases]

BACKGROUND

In this study patients with peripheral vascular disease were treated with PGE1 alpha-ciclodestrina. In the intermittent claudication group (walking distance at inclusion between 200-600 m) we included 55 patients treated with PGE1 alpha-ciclodestrina (15 diabetics) and 22 controls (not treated with PGE1 alpha-ciclodestrina). In the critical ischemia group 46 patients were treated and 47 patients followed up as controls (rest pain or necrotic lesions had been present for more than 2 weeks).

METHODS

Patients with intermittent claudication were evaluated by a treadmill test (walking distance was the endpoint) and in those with critical ischemia the number of minor and major amputations in 12 months were considered as endpoints. A dose of PGE1 alpha-ciclodestrina (60-80 micrograms/day for 2 days) was repeated either every 6 or, in alternative, every 10 weeks. In the control group only antiplatelet agents, support treatment (control of risk factors) and exercise were used.

RESULTS

All subgroups of patients treated with PGE1 alpha-ciclodestrina with intermittent claudication increased their walking distance (including the subgroup of diabetics). In critical ischemia there were no major amputations (only 2 minor amputations) in the PGE1 alpha-ciclodestrina group vs 10.6% (of major amputations) in the control group. Also an evaluation of laser Doppler flow, volume flow and transcutaneous PO2 indicated in subgroups of patients an improvement of microcirculation and limb perfusion with PGE1 alpha-ciclodestrina.

CONCLUSIONS

The cost analysis and the quality of life evaluation indicated a benefit of preserving limbs from amputation.

[Cardiovascular morbidity/mortality modified by the use of FGE1 alpha-cyclodextran and calcium heparin in patients with severe vascular diseases]

BACKGROUND

Morbidity and mortality were evaluated in three groups of vascular patients: one group was treated with PGE1 alpha-ciclodestrina according to the short term protocol; the second group was treated with PGE1 alpha-ciclodestrina and subcutaneous calcium heparin (SCH; 0.5 ml once daily, in the evening) while a third group was a historical reference group.

METHODS

All included patients had a follow up of at least 12 months. The historical reference group had been managed without PGE1 alpha-ciclodestrina or SCH while in the two PGE1 alpha-ciclodestrina groups included patients who had been treated with at least four PGE1 alpha-ciclodestrina short-term treatment cycles per year. The 3 groups were comparable for sex and age distribution. In the PGE1 alpha-ciclodestrina group 142 patients (64 +/- 17; M:F = 84:58) had been treated (47 for intermittent claudication and 95 for critical ischemia). The historical reference group included 157 patients (65 +/- 18: M:F = 91:66); 53 with intermittent claudication and 104 with critical ischemia). The group treated with PGE1 alpha-ciclodestrina and SCH included 74 patients (27 with claudication and 47 with critical ischemia).

RESULTS

In claudicants yearly cardiovascular morbidity was reduced from 15.5% in the reference group to 10.2% in patients treated with PGE1 alpha-ciclodestrina and to 7.9% in those treated with PGE1 alpha-ciclodestrina and SCH. Mortality decreased from 11.3% in the reference group to 6% in the PGE1 alpha-ciclodestrina group and to 5.1% in the PGE1 alpha-ciclodestrina + SCH group. In patients with critical limb ischemia morbidity decreased from 28.6% in the reference group to 23.2% in PGE1 alpha-ciclodestrina-group and to 19.4% in the PGE1 alpha-ciclodestrina + SCH group. Mortality also decreased from 16% (reference group) to 13% in the PGE1 alpha-ciclodestrinagroup, to 10.3% in the PGE1 alpha-ciclodestrina + SCH group.

CONCLUSION

Cyclic treatment with PGE1 alpha-ciclodestrina produces an important decrease in cardiovascular morbidity and mortality which could be further reduced by the chronic use of subcutaneous calcium heparin.

[European trial of PGE1 alpha cyclodextrin. Short-term vs. long-term therapy in intermittent claudication]

BACKGROUND

The efficacy, safety and cost of prostaglandin E1 (PGE1 alpha-ciclodestrina) in the treatment of severe intermittent claudication was studied comparing a long term treatment protocol (LTP) with a short term treatment protocol (STP) in a randomised, 20-week study.

METHODS

The study has selected 120 patients (109 were included and 99 completed the study). The average total walking distance at inclusion was 65.5 +/- 8 m (range 20-109). Phase 1 was a 2-week run-in phase (no treatment) for both protocols. In LTP phase 2 was the main treatment phase. The treatment was performed with 2-hour infusions (60 micrograms PGE1 alpha-ciclodestrina, 5 days each week for 4 weeks. In phase 3 (4-week interval period) PGE1 alpha-ciclodestrina was administered twice a week (same dosage). In phase 4 (monitoring lasting 3 months, from week 9 to 20) no drugs were used. In STP phase 2 treatment was performed in two days with a 2-hour infusion (1st day: morning 20 micrograms, afternoon 40 micrograms; 2nd day 60 micrograms, morning and afternoon). The reduced dosage was used only at the first cycle to evaluate reduced tolerability or side effects. Full dosage (60 micrograms b.i.d.) was used for all other cycles. The same cycle was repeated at the beginning of weeks 4, 8, 12 (phase 3). The observation period was between weeks 12 and 20 (phase 4). For both protocols a treadmill test was performed at inclusion, at the beginning of each phase and at the end of 20th week. A similar progressive physical training plan (based on walking) and a reduction in risk factors plan was used in both groups.

RESULTS

Intention-to-treat analysis indicated an increase in walking distance which improved at 4 weeks (101.5% in STP vs 78.3% in LTP), at 8 weeks (260.9% in STP vs 107.3% in LTP) and at 20 weeks (351% in STP vs 242% in LTP). Comparable increases in pain-free walking distance were observed in the two groups. No serious drug-related side effects were observed. Local, mild, adverse reactions were seen in 7% of the treated subjects in the LTP and 5% in the STP. The average cost of LTP was approximately 6.588 ECU; for STP the average costs was approximately 1881 ECU. The cost to achieve an improvement in walking distance of 1 m was 35.6 ECU with the LTP and 9.45 ECU with the STP (26% of the LTP cost; P < 0.02). For an average 100% increase in walking distance LTP cost was 1937 ECU vs 550 ECU with STP (P < 0.02). The cost of PGE1 alpha-ciclodestrina (including infusion and operative costs) was 25% of the total cost for LTP (24.9% for STP).

CONCLUSION

In summary between-group-analysis favours STP considering walking distance and costs. Results indicate good efficacy and tolerability of PGE1 alpha-ciclodestrina treatment. With STP less time is spent in infusion and more can be spent in the exercise program. STP reduces costs, speeds up rehabilitation and may be used in a larger number of non-specialised units available to follow the protocol.

[Increasing transcutaneous PO2 in arteriopathies during treatment with PGE1 alpha-cyclodextrin]

BACKGROUND

Transcutaneous PO2 values (at the dorsum of the foot) were evaluated in a group of 8 patients (mean age 66 +/- 11) with critical ischemia including 4 patients (mean age 65 +/- 10) with gangrene[. A group of 5 comparable normal controls was also studied.

METHODS

Patients were treated with PGE1 alpha-ciclodestrina (60 mu/die, in two infusions lasting 3 hours; one in the morning and one in the afternoon) for 6 days.

RESULTS

Results indicated a maximum increase in PO2 between the second and third day which remains higher than values observed before treatment up to 4 weeks. In another group of patients (6 claudicants with walking distance between 200 and 400 m, 4 with rest pain and 4 with localised gangrene) PO2 foot/chest ratio was studied. The ratio was significantly increased after 6 days of PGE1 alpha-ciclodestrina treatment. The evaluation of PO2 with an exercise test on treadmill (including 6 claudicants, 4 patients with rest pain and 5 normal controls) indicated a large decrease in PO2 with exercise in limbs with critical ischemia; the PO2 decrease on effort was less visible in claudicants. Recovery time to pre-exercise values was also very long in subjects with critical ischemia. The exercise test may be useful to monitor the efficacy of PGE1 alpha-ciclodestrina treatment. However the test is not standardised and commonly used.

CONCLUSIONS

In conclusion this study indicated that PO2 increases after PGE1 alpha-ciclodestrina treatment may last for at least 4 weeks and also that transcutaneous PO2 could be an effective method to follow up changes in perfusion. However tests based on PO2 measurements should be standardised to constitute a common evaluation method.

[Reduction of cardiovascular morbidity/mortality in arteriopathies treated ith PGE1 alpha-cyclodextrin]

BACKGROUND

Cardiovascular morbidity and mortality were evaluated in two groups of vascular patients (one treated with PGE1 alpha-ciclodestrina according to the short term protocol and one reference group) with a follow up of at least 24 month.

METHODS

The former group included patients who had been treated with at least four PGE1 alpha-ciclodestrina, short-term treatment cycles per year while the latter was a historical reference group managed without prostaglandins. The two groups were comparable for sex and age distribution.

RESULTS

In the PGE1 alpha-ciclodestrina group 142 patients (mean age 64 +/- 17; M:F = 84:58) had been treated (47 for intermittent claudication and 95 for critical ischemia: 43 for rest pain, and 52 for localised gangrene). The historical reference group included 157 patients (mean age 65 +/- 18: M:F = 91:66); 53 with intermittent claudication and 104 with critical ischemia (49 rest pain, 55 gangrene). In claudicants yearly cardiovascular morbidity was reduced from the 15% observed in the reference group to 10% in patients treated with PGE1 alpha-ciclodestrina. Yearly mortality decreased from 11% in the reference group to 6% in the treated group. In rest pain patients morbidity decreased from 24% in the reference group to 19% in the treated group. Mortality also decreased (from 16% to 11%). In patients with gangrene the difference in morbidity between the reference group (35%) and the PGE1 alpha-ciclodestrina group (27%) was even more evident (P < 0.025). In this group the mortality per year was reduced from 26% in the reference group to 17% in the PGE1 alpha-ciclodestrina treated group.

CONCLUSION

It appears that cyclic treatment with PGE1 alpha-ciclodestrina produces not only an improvement in signs and symptoms related to vascular disease but also an important decrease in cardiovascular morbidity and mortality which has not been previously reported.