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1.
Transl Neurodegener ; 13(1): 6, 2024 01 22.
Article in English | MEDLINE | ID: mdl-38247000

ABSTRACT

Neurodegenerative disorders present complex pathologies characterized by various interconnected factors, including the aggregation of misfolded proteins, oxidative stress, neuroinflammation and compromised blood-brain barrier (BBB) integrity. Addressing such multifaceted pathways necessitates the development of multi-target therapeutic strategies. Emerging research indicates that probucol, a historic lipid-lowering medication, offers substantial potential in the realm of neurodegenerative disease prevention and treatment. Preclinical investigations have unveiled multifaceted cellular effects of probucol, showcasing its remarkable antioxidative and anti-inflammatory properties, its ability to fortify the BBB and its direct influence on neural preservation and adaptability. These diverse effects collectively translate into enhancements in both motor and cognitive functions. This review provides a comprehensive overview of recent findings highlighting the efficacy of probucol and probucol-related compounds in the context of various neurodegenerative conditions, including Alzheimer's disease, Parkinson's disease, Huntington's disease, and cognitive impairment associated with diabetes.


Subject(s)
Alzheimer Disease , Neurodegenerative Diseases , Parkinson Disease , Humans , Neurodegenerative Diseases/drug therapy , Probucol/therapeutic use , Blood-Brain Barrier
2.
PeerJ Comput Sci ; 9: e1286, 2023.
Article in English | MEDLINE | ID: mdl-37346713

ABSTRACT

In this article we propose the first multi-task benchmark for evaluating the performances of machine learning models that work on low level assembly functions. While the use of multi-task benchmark is a standard in the natural language processing (NLP) field, such practice is unknown in the field of assembly language processing. However, in the latest years there has been a strong push in the use of deep neural networks architectures borrowed from NLP to solve problems on assembly code. A first advantage of having a standard benchmark is the one of making different works comparable without effort of reproducing third part solutions. The second advantage is the one of being able to test the generality of a machine learning model on several tasks. For these reasons, we propose BinBench, a benchmark for binary function models. The benchmark includes various binary analysis tasks, as well as a dataset of binary functions on which tasks should be solved. The dataset is publicly available and it has been evaluated using baseline models.

3.
Pharmaceutics ; 15(2)2023 Feb 04.
Article in English | MEDLINE | ID: mdl-36839852

ABSTRACT

A novel gliclazide-loaded elastomeric carbohydrate pharmaceutical vehicle was successfully developed. This new siliconized alginate platform showed pseudoplastic rheology with a zeta potential ranging from (-43.8 mV to -75.5 mV). A Buchi-B390 encapsulator was employed to formulate different types of silicone-grafted alginate microcapsules loaded with gliclazide relying on the vibrational ionic gelation technology. The use of tetraethyl orthosilicate (TEOS) to crosslink the silicone elastomer (hydroxy terminated polydimethylsiloxane) of this new platform had improved the gliclazide encapsulation (>92.13% ± 0.76) of the free-flowing composite microcapsules, which showed good mechanical durability (up to 12 h in PBS pH 6.8) and promising results to sustain the drug release.

4.
Pharmaceutics ; 15(2)2023 Feb 06.
Article in English | MEDLINE | ID: mdl-36839865

ABSTRACT

Pigment epithelium-derived factor (PEDF) is a secreted glycoprotein that belongs to the serine protease inhibitor (serpin) family. An increase in PEDF activity has been shown to be a potent inhibitor of tumour progression and proliferation, suggesting a possible therapeutic target. There is still a great deal to learn about how PEDF controls metabolic pathways in breast cancer and its metastatic form. Given this, the primary purpose of this study was to use a metabolomics approach to gain a better understanding of the mechanisms driving the reprogramming of metabolic events involved in breast cancer pertaining to PEDF under various glycaemic loads. We employed gas chromatography-quadrupole mass spectrometry (GC-Q-MS) to investigate metabolic changes in the triple-negative breast cancer (TNBC) cell line MDA-MB-231 treated with PEDF under glycaemic loading. Multivariate and univariate analyses were carried out as indicative tools via MetaboAnalyst (V.5.0) and R packages to identify the significantly altered metabolites in the MDA-MB-231 cell line after PEDF exposure under glycaemic loading. A total of 61 metabolites were found, of which nine were selected to be distinctively expressed in MDA-MB-231 cells under glycaemic conditions and exhibited differential responses to PEDF (p < 0.05, VIP > 1). Abnormalities in amino acid metabolism pathways were observed. In particular, glutamic acid, glutamine, and phenylalanine showed different levels of expression across different treatment groups. The lactate and glucose-6-phosphate production significantly increased in high-glucose vs. normal conditions while it decreased when the cells were exposed to PEDF, confirming the positive influence on the Warburg effect. The TCA cycle intermediates, including malate and citric acid, showed different patterns of expression. This is an important finding in understanding the link of PEDF with metabolic perturbation in TNBC cells in response to glycaemic conditions. Our findings suggest that PEDF significantly influenced the Warburg effect (as evidenced by the significantly lower levels of lactate), one of the well-known metabolic reprogramming pathways in cancer cells that may be responsive to metabolic-targeted therapeutic strategies. Moreover, our results demonstrated that GC-MS-based metabolomics is an effective tool for identifying metabolic changes in breast cancer cells after glycaemic stress or in response to PEDF treatment.

5.
Curr Diabetes Rev ; 18(1): e062620183199, 2022.
Article in English | MEDLINE | ID: mdl-32589561

ABSTRACT

AIM: Examine bile acids effects in Type 2 diabetes. BACKGROUND: In recent studies, the bile acid ursodeoxycholic acid (UDCA) has shown potent antiinflammatory effects in obese patients while in type 2 diabetics (T2D) levels of the pro-inflammatory bile acid lithocholic acid were increased, and levels of the anti-inflammatory bile acid chenodeoxycholic acid were decreased, in plasma. OBJECTIVE: Hence, this study aimed to examine applications of novel UDCA microparticles in diabetes. METHODS: Diabetic balb/c adult mice were divided into three equal groups and gavaged daily with either empty microcapsules, free UDCA, or microencapsulated UDCA over two weeks. Their blood, tissues, urine, and faeces were collected for blood glucose, inflammation, and bile acid analyses. UDCA resulted in modulatory effects on bile acids profile without antidiabetic effects suggesting that bile acid modulation was not directly linked to diabetes treatment. RESULTS: UDCA resulted in modulatory effects on bile acids profile without antidiabetic effects suggesting that bile acid modulation was not directly linked to diabetes treatment. CONCLUSION: Bile acids modulated the bile profile without affecting blood glucose levels.


Subject(s)
Bile Acids and Salts , Diabetes Mellitus, Type 2 , Animals , Diabetes Mellitus, Type 2/drug therapy , Disease Models, Animal , Humans , Mice , Mice, Inbred BALB C , Ursodeoxycholic Acid/pharmacology
6.
Pharmaceutics ; 13(5)2021 May 03.
Article in English | MEDLINE | ID: mdl-34063593

ABSTRACT

Astaxanthin (ASX) is a potent lipophilic antioxidant derived from the natural pigment that gives marine animals their distinctive red-orange colour and confers protection from ultraviolet radiation. Self nano-emulsifying drug delivery systems (SNEDDS) have been successfully developed and evaluated to increase the skin penetration of ASX and target its antioxidant and anti-inflammatory potential to the epidermis and dermis. SNEDDS were prepared using a low-temperature spontaneous emulsification method, and their physical characteristics, stability, antioxidant activity, and skin penetration were characterized. Terpenes (D-limonene, geraniol, and farnesol) were included in the SNEDDS formulations to evaluate their potential skin penetration enhancement. An HPLC assay was developed that allowed ASX recovery from skin tissues and quantification. All SNEDDS formulations had droplets in the 20 nm range, with low polydispersity. ASX stability over 28 days storage in light and dark conditions was improved and antioxidant activity was high. SNEDDS-L1 (no terpene) gave significantly increased ASX penetration to the stratum corneum (SC) and the epidermis-dermis-follicle region (E + D + F) compared to an ASX in oil solution and a commercial ASX facial serum product. The SNEDDS-containing D-limonene gave the highest ASX permeation enhancement, with 3.34- and 3.79-fold the amount in the SC and E + D + F, respectively, compared to a similar applied dose of ASX in oil. We concluded that SNEDDS provide an effective formulation strategy for enhanced skin penetration of a highly lipophilic molecule, and when applied to ASX, have the potential to provide topical formulations for UV protection, anti-aging, and inflammatory conditions of the skin.

7.
PeerJ Comput Sci ; 7: e466, 2021.
Article in English | MEDLINE | ID: mdl-33981837

ABSTRACT

In this paper we investigate dynamic networks populated by autonomous mobile agents. Dynamic networks are networks whose topology can change continuously, at unpredictable locations and at unpredictable times. These changes are not considered to be faults, but rather an integral part of the nature of the system. The agents can autonomously move on the network, with the goal of solving cooperatively an assigned common task. Here, we focus on a specific network: the unoriented ring. More specifically, we study 1-interval connected dynamic rings (i.e., at any time, at most one of the edges might be missing). The agents move according to the widely used Look-Compute-Move life cycle, and can be homogenous (thus identical) or heterogenous (agents are assigned colors from a set of c > 1 colors). For identical agents, their goal is to form a compact segment, where agents occupy a continuous part of the ring and no two agents occupy the same node: we call this the Compact Configuration Problem. In the case of agents with colors, called the Colored Compact Configuration Problem, the goal is to group agents such that each group is formed by all agents having the same color, it occupies a continuous segment of the network, and groups of agents having different colors occupy distinct areas of the network. In this paper we determine the necessary conditions to solve both proposed problems. For all solvable cases, we provide algorithms for both the monochromatic and the colored version of the compact configuration problem. All our algorithms work even for the simplest model where agents have no persistent memory, no communication capabilities and do not agree on a common orientation within the network. To the best of our knowledge this is the first work on the compaction problem in a dynamic network.

8.
Sci Rep ; 10(1): 21037, 2020 12 03.
Article in English | MEDLINE | ID: mdl-33273555

ABSTRACT

Hepatorenal syndrome (HRS) is a fatal complication of renal dysfunction associated with ascites, liver failure and advanced cirrhosis. Although the best option for long-term survival is liver transplantation, in the critical acute phase, vasoconstrictors are considered first-line supportive agents. Terlipressin is the most widely used vasoconstrictor globally but owing to its short elimination half-life, it is usually administered six hourly by slow intravenous bolus injection. This requires patients to remain in hospital, increasing hospital bed costs and affecting their quality of life. An alternative option for administration of terlipressin is as a continuous infusion using an elastomeric infusor device in the patient's home. However, stability data on terlipressin in elastomeric infusor devices is lacking. This research aimed to evaluate the stability of terlipressin reconstituted in infusor devices for up to 7 days at 2-8 °C and subsequently at 22.5 °C for 24 h, to mimic home storage and administration temperatures. We report that terlipressin was physically and chemically stable under these conditions; all reconstituted infusor concentrations retained above 90% of the original concentration over the test conditions. No colour change or precipitation in the solutions were evident.


Subject(s)
Hepatorenal Syndrome/drug therapy , Infusion Pumps/standards , Terlipressin/administration & dosage , Vasoconstrictor Agents/administration & dosage , Drug Stability , Humans , Infusions, Intravenous/instrumentation , Infusions, Intravenous/methods , Terlipressin/chemistry , Terlipressin/therapeutic use , Vasoconstrictor Agents/chemistry , Vasoconstrictor Agents/therapeutic use
9.
RSC Adv ; 10(13): 7523-7540, 2020 Feb 23.
Article in English | MEDLINE | ID: mdl-33014349

ABSTRACT

Our group has previously reported several indolecarboxamides exhibiting potent antitubercular activity. Herein, we rationally designed several arylcarboxamides based on our previously reported homology model and the recently published crystal structure of the mycobacterial membrane protein large 3 (MmpL3). Many analogues showed considerable anti-TB activity against drug-sensitive (DS) Mycobacterium tuberculosis (M. tb) strain. Naphthamide derivatives 13c and 13d were the most active compounds in our study (MIC: 6.55, 7.11 µM, respectively), showing comparable potency to the first line anti-tuberculosis (anti-TB) drug ethambutol (MIC: 4.89 µM). In addition to the naphthamide derivatives, we also identified the quinolone-2-carboxamides and 4-arylthiazole-2-carboxamides as potential MmpL3 inhibitors in which compounds 8i and 18b had MIC values of 9.97 and 9.82 µM, respectively. All four compounds retained their high activity against multidrug-resistant (MDR) and extensively drug-resistant (XDR) M. tb strains. It is worth noting that the two most active compounds 13c and 13d also exhibited the highest selective activity towards DS, MDR and XDR M. tb strains over mammalian cells [IC50 (Vero cells) ≥ 227 µM], indicating their potential lack of cytotoxicity. The four compounds were docked into the MmpL3 active site and were studied for their drug-likeness using Lipinski's rule of five.

10.
Pharmacol Res Perspect ; 8(6): e00668, 2020 12.
Article in English | MEDLINE | ID: mdl-33090729

ABSTRACT

Benzathine penicillin G (BPG) is used as first-line treatment for most forms of syphilis and as secondary prophylaxis against rheumatic heart disease (RHD). Perceptions that poor quality of BPG is linked to reported adverse effects and therapeutic failure may impact syphilis and RHD control programs. Clinical networks and web-based advertising were used to obtain vials of BPG from a wide range of countries. The quality of BPG was assessed using a high performance liquid chromatography assay capable of detecting relevant impurities and degradation products. Tests for water content, presence of heavy metals and physical characteristics of BPG, including particle size analysis and optical microscopy, also were conducted. Thirty-five batches of BPG were sourced from 16 countries across 4 WHO regions. All batches passed the US Pharmacopeia requirements for BPG injection (content), with no evidence of breakdown products or other detected contaminants. Water content and heavy metal analysis (n = 11) indicated adherence to regulatory standards and Good Manufacturing Practice. Particle size analysis (n = 20) found two batches with aggregated particles (>400 µm) that were dispersed following sonication. Current batches of BPG were of satisfactory pharmaceutical quality but aggregated particles were found in a modest proportion of samples. Future studies should focus on the physical characteristics of BPG which may contribute to variations in plasma penicillin concentrations an observed needle blockages in clinical practice. Pharmacopeial monographs could be revised to include standards on particle size and crystal morphology of BPG.


Subject(s)
Anti-Bacterial Agents/standards , Chemistry, Pharmaceutical/standards , Internationality , Penicillin G Benzathine/standards , Quality Control , Anti-Bacterial Agents/therapeutic use , Chemistry, Pharmaceutical/methods , Cross-Sectional Studies , Humans , Penicillin G Benzathine/therapeutic use , Rheumatic Heart Disease/drug therapy
11.
Pharmacol Rep ; 72(2): 368-378, 2020 Apr.
Article in English | MEDLINE | ID: mdl-32048259

ABSTRACT

BACKGROUND: Ursodeoxycholic acid (UDCA) is a secondary hydrophilic bile acid, metabolised in the gut, by microbiota. UDCA is currently prescribed for primary biliary cirrhosis, and of recently has shown ß-cell protective effects, which suggests potential antidiabetic effects. Thus, this study aimed to design targeted-delivery microcapsules for oral uptake of UDCA and test its effects in type 1 diabetes (T1D). METHODS: UDCA microcapsules were produced using alginate-NM30 matrix. Three equal groups of mice (6-7 mice per group) were gavaged daily UDCA powder, empty microcapsules and UDCA microcapsules for 7 days, then T1D was induced by alloxan injection and treatments continued until mice had to be euthanised due to weight loss > 10% or severe symptoms develop. Plasma, tissues, and faeces were collected and analysed for bile acids' concentrations. RESULTS: UDCA microcapsules brought about reduction in elevated blood glucose, reduced inflammation and altered concentrations of the primary bile acid chenodeoxycholic acid and the secondary bile acid lithocholic acid, without affecting survival rate of mice. CONCLUSION: The findings suggest that UDCA exerted direct protective effects on pancreatic ß-cells and this is likely to be associated with alterations of concentrations of primary and secondary bile acids in plasma and tissues. Three equal groups of mice were gavaged daily UDCA (ursodeoxycholic acid) powder, empty microcapsules and UDCA microcapsules for 7 days, then T1D was induced and treatments continued until mice had to be euthanised. UDCA microcapsules brought about reduction in elevated blood glucose, reduced inflammation and altered concentrations of the primary bile acid chenodeoxycholic acid and the secondary bile acid lithocholic acid, without affecting survival rate of mice. The findings suggest that UDCA exerted direct protective effects on pancreatic ß-cells and this is likely to be associated with alterations of concentrations of primary and secondary bile acids in plasma and tissues.


Subject(s)
Acrylates/pharmacology , Bile Acids and Salts/metabolism , Blood Glucose/metabolism , Diabetes Mellitus, Experimental/drug therapy , Diabetes Mellitus, Type 1/drug therapy , Nanoconjugates/chemistry , Ursodeoxycholic Acid/pharmacology , Acrylates/chemistry , Acrylates/metabolism , Animals , Bile Acids and Salts/blood , Bile Acids and Salts/urine , Chenodeoxycholic Acid/blood , Chenodeoxycholic Acid/metabolism , Chenodeoxycholic Acid/urine , Diabetes Mellitus, Experimental/blood , Diabetes Mellitus, Experimental/metabolism , Diabetes Mellitus, Type 1/blood , Diabetes Mellitus, Type 1/metabolism , Feces/chemistry , Insulin/blood , Lithocholic Acid/blood , Lithocholic Acid/metabolism , Lithocholic Acid/urine , Mice , Ursodeoxycholic Acid/chemistry , Ursodeoxycholic Acid/metabolism
12.
Curr Diabetes Rev ; 16(8): 900-909, 2020.
Article in English | MEDLINE | ID: mdl-32013849

ABSTRACT

BACKGROUND: Recent studies have suggested that hyperglycaemia influences the bile acid profile and concentrations of secondary bile acids in the gut. INTRODUCTION: This study aimed to measure changes in the bile acid profile in the gut, tissues, and faeces in type 1 Diabetes (T1D) and Type 2 Diabetes (T2D). METHODS: T1D and T2D were established in a mouse model. Twenty-one seven-weeks old balb/c mice were randomly divided into three equal groups, healthy, T1D and T2D. Blood, tissue, urine and faeces samples were collected for bile acid measurements. RESULTS: Compared with healthy mice, T1D and T2D mice showed lower levels of the primary bile acid, chenodeoxycholic acid, in the plasma, intestine, and brain, and higher levels of the secondary bile acid, lithocholic acid, in the plasma and pancreas. Levels of the bile acid ursodeoxycholic acid were undetected in healthy mice but were found to be elevated in T1D and T2D mice. CONCLUSION: Bile acid profiles in other organs were variably influenced by T1D and T2D development, which suggests similarity in effects of T1D and T2D on the bile acid profile, but these effects were not always consistent among all organs, possibly since feedback mechanisms controlling enterohepatic recirculation and bile acid profiles and biotransformation are different in T1D and T2D.


Subject(s)
Cholic Acids/analysis , Diabetes Mellitus, Type 1 , Diabetes Mellitus, Type 2 , Animals , Bile Acids and Salts/analysis , Bile Acids and Salts/blood , Bile Acids and Salts/urine , Blood Glucose/analysis , Brain Chemistry , Cholic Acids/blood , Cholic Acids/urine , Diabetes Mellitus, Experimental/blood , Diabetes Mellitus, Experimental/urine , Diabetes Mellitus, Type 1/blood , Diabetes Mellitus, Type 1/urine , Diabetes Mellitus, Type 2/blood , Diabetes Mellitus, Type 2/urine , Disease Models, Animal , Feces/chemistry , Gastrointestinal Tract/chemistry , Hyperglycemia/blood , Hyperglycemia/urine , Male , Mice , Mice, Inbred BALB C , Muscles/chemistry , Random Allocation
13.
Int J Pharm ; 572: 118720, 2019 Dec 15.
Article in English | MEDLINE | ID: mdl-31715357

ABSTRACT

Therapeutic proteins are labile macromolecules that are prone to degradation during production, freeze-drying and storage. Recent studies showed that nanoparticles can enhance the stability and oral bioavailability of encapsulated proteins. Several conventional approaches (enzyme inhibitors, mucoadhesive polymers) and novel strategies (surface modification, ligand conjugation, flash nano-complexation, stimuli-responsive drug delivery systems) have been employed to improve the physiochemical properties of nanoparticles such as size, zeta potential, morphology, polydispersity index, drug release kinetics and cell-targeting capacity. However, clinical translation of protein-based nanoparticle is limited due to poor experimental design, protocol non-compliance and instrumentation set-up that do not reflect the physiological conditions, resulting in difficulties in mass production of nanoparticles and waste in research funding. In order to address the above concerns, we conducted a comprehensive review to examine the experimental designs and conditions for physical characterization of protein-based nanoparticles. Reliable and robust characterization is essential to verify the cellular interactions and therapeutic potential of protein-based nanoparticles. Importantly, there are a number of crucial factors, which include sample treatment, analytical method, dispersants, sampling grid, staining, quantification parameters, temperature, drug concentration and research materials, should be taken into careful consideration. Variations in research protocol and unreasonable conditions that are used in optimization of pharmaceutical formulations can have great impact in result interpretation. Last but not least, we reviewed all novel instrumentations and assays that are available to examine mucus diffusion capacity, stability and bioactivity of protein-based nanoparticles. These include circular dichroism, fourier transform infrared spectroscopy, X-ray diffractogram, UV spectroscopy, differential scanning calorimetry, fluorescence spectrum, Förster resonance energy transfer, NMR spectroscopy, Raman spectroscopy, cellular assays and animal models.


Subject(s)
Nanoparticles/chemistry , Proteins/chemistry , Administration, Oral , Animals , Drug Liberation , Drug Stability , Humans , Mucins/chemistry , Nanoparticles/administration & dosage , Nanotechnology , Particle Size , Proteins/administration & dosage , Research Design
14.
Pharm Dev Technol ; 24(10): 1272-1277, 2019 Dec.
Article in English | MEDLINE | ID: mdl-31557068

ABSTRACT

Studies in our laboratory have shown potential applications of the anti-atherosclerotic drug probucol (PB) in diabetes due to anti-inflammatory and ß-cell protective effects. The anti-inflammatory effects were optimized by incorporation of the anti-inflammatory bile acid, ursodeoxycholic acid (UDCA). This study aimed to test PB absorption, tissue accumulation profiles, effects on inflammation and type 1 diabetes prevention when combined with UDCA. Balb/c mice were divided into three equal groups and gavaged daily PB powder, PB microcapsules or PB-UDCA microcapsules for one week, at a constant dose. Mice were injected with a single dose of intraperitoneal/subcutaneous alloxan to induce type-1 diabetes and once diabetes was confirmed, treatments were continued for 3 days. Mice were euthanized and blood and tissues collected for analysis of PB and cytokine levels. The PB-UDCA group showed the highest PB concentrations in blood, gut, liver, spleen, brain, and white adipose tissues, with no significant increase in pancreas, heart, skeletal muscles, kidneys, urine or feces. Interferon gamma in plasma was significantly reduced by PB-UDCA suggesting potent anti-inflammatory effects. Blood glucose levels remained similar after treatments, while survival was highest among the PB-UDCA group. Our findings suggest that PB-UDCA resulted in best PB blood and tissue absorption and reduced inflammation.


Subject(s)
Anti-Inflammatory Agents/therapeutic use , Diabetes Mellitus, Experimental/drug therapy , Diabetes Mellitus, Type 1/drug therapy , Insulin-Secreting Cells/drug effects , Probucol/therapeutic use , Ursodeoxycholic Acid/therapeutic use , Animals , Anti-Inflammatory Agents/administration & dosage , Anti-Inflammatory Agents/pharmacokinetics , Drug Combinations , Drug Compounding , Excipients/chemistry , Mice, Inbred BALB C , Particle Size , Probucol/administration & dosage , Probucol/pharmacokinetics , Tissue Distribution , Ursodeoxycholic Acid/administration & dosage , Ursodeoxycholic Acid/pharmacokinetics
15.
Drug Des Devel Ther ; 13: 2655-2665, 2019.
Article in English | MEDLINE | ID: mdl-31447546

ABSTRACT

PURPOSE: To evaluate the stability of meropenem trihydrate in elastomeric infusion devices at a range of selected concentrations (6, 12, 20 and 25 mg/mL) at ambient, refrigeration and freezing temperatures. METHODS: Meropenem Ranbaxy® (meropenem trihydrate equivalent to anhydrous meropenem 1 g) vials for injection were reconstituted with 0.9% sodium chloride and adjusted to pH 6.5 using 1 M hydrochloric acid. Following preparation, solutions were stored for 7 days at either 6.7°C in elastomeric infusion devices or at -19°C in glass vials; samples of each concentration were removed from the infusion devices at specific time-points and stored for 24 hrs at 22.5°C. All solutions were assayed at specific time-points using high-performance liquid chromatography. Forced degradation in hydrochloric acid, sodium hydroxide and hydrogen peroxide was carried out at 40°C. RESULTS: The lowest concentration of meropenem (6 mg/mL) displayed the highest stability. It maintained >90% of its initial concentration for up to 144 hrs when stored at 6.7°C and 72 hrs following 24 hrs storage at 22.5°C, having been initially refrigerated for 48 hrs. Meropenem 20 mg/mL required immediate administration following preparation under ambient temperatures, whilst meropenem 25 mg/mL did not remain stable following 24 hrs storage at ambient temperatures. Frozen meropenem solutions displayed good stability in all concentrations but were physically unstable due to the formation of a precipitate. CONCLUSION: At lower concentrations, meropenem showed suitable stability for storage and administration in elastomeric infusion devices, at refrigerated temperatures. To enhance the stability of lower concentration solutions when exposed to ambient temperatures by ambulatory patients, a more adept method of maintaining lower temperatures that reflect refrigerated conditions for elastomeric infusion devices should be devised.


Subject(s)
Elastomers/chemistry , Infusion Pumps , Meropenem/analysis , Drug Stability , Freezing , Refrigeration
16.
PLoS One ; 14(4): e0214984, 2019.
Article in English | MEDLINE | ID: mdl-30947243

ABSTRACT

Type 2 diabetes (T2D) is characterised by ß-cell damage and hyperglycaemia. The lipophilic drug, probucol, has shown significant ß-cell protective and potential antidiabetic effects, which were enhanced by hydrophilic bile acid incorporation using taurocholic acid and chenodeoxycholic acid. However, probucol has severe cardiotoxicity and a variable absorption profile, which limit its potential applications in T2D. Accordingly, this study aimed to design multiple formulations to optimise probucol oral delivery in T2D and test their effects on probucol absorption and accumulation in the heart. Adult male mice were given a high fat diet (HFD), and a week later, injected with a single dose of alloxan to accelerate T2D development, and once diabetes confirmed, divided into three groups (six to seven mice each). The groups were gavaged a daily dose of probucol powder, probucol microcapsules, or probucol-bile acid microcapsules for three months, and euthanized; and blood, tissues, and feces collected for blood glucose and probucol concentration analyses. Probucol concentrations in plasma were similar among all the groups. Groups given probucol microcapsules and probucol-bile acid microcapsules showed significant reduction in probucol accumulation in the heart compared with the group given probucol powder (p<0.05). Probucol microencapsulation with or without bile acids reduced its accumulation in heart tissues, without changing plasma concentrations, which may be beneficial in reducing its cardiotoxicity and optimise its potential applications in T2D.


Subject(s)
Diabetes Mellitus, Type 2 , Probucol , Administration, Oral , Animals , Capsules , Cardiotoxicity/blood , Cardiotoxicity/prevention & control , Diabetes Mellitus, Experimental/blood , Diabetes Mellitus, Experimental/drug therapy , Diabetes Mellitus, Type 2/blood , Diabetes Mellitus, Type 2/drug therapy , Dietary Fats/adverse effects , Dietary Fats/pharmacology , Male , Mice , Mice, Inbred BALB C , Myocardium/metabolism , Probucol/pharmacokinetics , Probucol/pharmacology
17.
ChemMedChem ; 14(7): 714-743, 2019 04 03.
Article in English | MEDLINE | ID: mdl-30740924

ABSTRACT

Xanthine oxidase (XO) is the enzyme responsible for the catabolism of purines and their conversion into uric acid. XO is thus the target for the treatment of hyperuricemia and gout. For more than 50 years the only XO inhibitor drug available on the market was the purine analogue allopurinol. In the last decade there has been a resurgence in the search for new inhibitors of XO, as the activity of XO and hyperuricemia have also been associated with a variety of conditions such as diabetes, hypertension, and other cardiovascular diseases. In recent years the non-purine inhibitor febuxostat was approved in Europe and the USA for the treatment of hyperuricemia. This drug was followed by another XO inhibitor called topiroxostat. This review discusses the molecular structures and activities of the multiple classes of inhibitors that have been developed since the discovery of allopurinol, with a brief review of the molecular interactions between inhibitors and XO active site residues for the most important molecules. The challenges ahead for the discovery of new inhibitors of XO with novel chemical structures are discussed.


Subject(s)
Enzyme Inhibitors/chemistry , Enzyme Inhibitors/pharmacology , Xanthine Oxidase/antagonists & inhibitors , Animals , Drug Design , Humans , Purines/chemistry , Structure-Activity Relationship , Xanthine Oxidase/chemistry
18.
Drug Des Devel Ther ; 11: 2087-2097, 2017.
Article in English | MEDLINE | ID: mdl-28744100

ABSTRACT

PURPOSE: The aim was to evaluate the stability of linezolid in commonly used intravenous fluids and in aqueous solution to determine the kinetics of degradation and shelf-life values at alkaline pH values. METHODS: Forced degradation studies were performed on linezolid in solution to develop a validated high-performance liquid chromatography analysis. Sodium chloride 0.9%, sodium lactate, and glucose 5% and glucose 10% solution containing 2.0 mg/mL linezolid were stored at 25.0°C (±0.1°C) for 34 days. The effect of temperature on the stability of linezolid in 0.1 M sodium hydroxide solution was investigated to determine the activation energy. The degradation rates of linezolid at selected pH values at 70.0°C and the influence of ionic strength were also examined. Activation energy data were applied to determine the shelf-life values at selected pH values, and a pH rate profile was constructed over the pH range of 8.7-11.4. The stability of intravenous linezolid (Zyvox®) solution was evaluated by storing at 70.0°C for 72 hours. RESULTS: Linezolid was found to maintain >95.0% of its initial concentration after storage at 25.0°C for 34 days in sodium lactate, 0.9% in sodium chloride, and 5% and 10% in glucose solutions. Linezolid was degraded at alkaline pH values by first-order kinetics. Activation energy data showed that temperature, but not ionic strength, influenced the degradation rate significantly. An activation energy of 58.22 kJ/mol was determined for linezolid in 0.1 M sodium hydroxide solution. Linezolid was least stable at high pH values and at elevated temperatures. It was determined that linezolid has adequate stability for the preparation of intravenous fluids for clinical administration. CONCLUSION: Linezolid was found to have a shelf life of 34 days at 25°C when added to sodium lactate, 0.9% sodium chloride, and 5% and 10% glucose solutions. It was least stable at high pH values and at elevated temperatures.


Subject(s)
Anti-Bacterial Agents/analysis , Linezolid/analysis , Chromatography, High Pressure Liquid , Drug Stability , Drug Storage , Glucose/chemistry , Hydrogen-Ion Concentration , Infusions, Intravenous , Lactic Acid/chemistry , Sodium Chloride/chemistry , Solutions , Spectrophotometry, Ultraviolet , Temperature , Water
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