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1.
Heliyon ; 10(4): e26025, 2024 Feb 29.
Article de Anglais | MEDLINE | ID: mdl-38384517

RÉSUMÉ

The mechanism governing pharmaceutical tablet disintegration is far from fully understood. Despite the importance of controlling a formulation's disintegration process to maximize the active pharmaceutical ingredient's bioavailability and ensure predictable and consistent release profiles, the current understanding of the process is based on indirect or superficial measurements. Formulation science could, therefore, additionally deepen the understanding of the fundamental physical principles governing disintegration based on direct observations of the process. We aim to help bridge the gap by generating a series of time-resolved X-ray micro-computed tomography (µCT) images capturing volumetric images of a broad range of mini-tablet formulations undergoing disintegration. Automated image segmentation was a prerequisite to overcoming the challenges of analyzing multiple time series of heterogeneous tomographic images at high magnification. We devised and trained a convolutional neural network (CNN) based on the U-Net architecture for autonomous, rapid, and consistent image segmentation. We created our own µCT data reconstruction pipeline and parameterized it to deliver image quality optimal for our CNN-based segmentation. Our approach enabled us to visualize the internal microstructures of the tablets during disintegration and to extract parameters of disintegration kinetics from the time-resolved data. We determine by factor analysis the influence of the different formulation components on the disintegration process in terms of both qualitative and quantitative experimental responses. We relate our findings to known formulation component properties and established experimental results. Our direct imaging approach, enabled by deep learning-based image processing, delivers new insights into the disintegration mechanism of pharmaceutical tablets.

2.
Front Pharmacol ; 14: 1246892, 2023.
Article de Anglais | MEDLINE | ID: mdl-38089057

RÉSUMÉ

Recently, the Amazonian plant medicine "ayahuasca"-containing the psychedelic compound N,N-dimethyltryptamine (DMT) and numerous ß-carboline alkaloids, such as harmine-has been suggested to exhibit beneficial effects in patients with affective and other mental health disorders. Although ayahuasca ingestion is considered safe, its pharmacokinetics/pharmacodynamics and tolerability profile pose some challenges and may limit the clinical applicability in vulnerable patient populations. While overdosing and the admixture of intolerable plant constituents may explain some of the common adverse reactions, the peroral route of administration may represent another relevant source of gastro-intestinal intolerabilities and unpredictable pharmacokinetics across users. To overcome these challenges, the present work aimed at creating ayahuasca-analogue formulations with improved pharmacokinetics and tolerability profiles. To this end, we developed peroral formulas and compared them with parenteral formulas specifically designed to circumvent the gastro-intestinal tract. In more detail, peroral administration of a capsule (containing purified DMT and harmine) was tested against a combined administration of an oromucosal harmine tablet and an intranasal DMT spray at two dose levels in an open-label within-subject study in 10 healthy male subjects. Pharmacokinetic and pharmacodynamic profiles were assessed by means of continuous blood sampling, vital sign monitoring, and psychometric assessments. Common side effects induced by traditional herbal ayahuasca such as nausea, vomiting, and diarrhea were significantly attenuated by our DMT/harmine formulations. While all preparations were well tolerated, the combined buccal/intranasal administration of harmine and DMT yielded substantially improved pharmacokinetic profiles, indicated by significantly reduced variations in systemic exposure. In conclusion, the combined buccal/intranasal administration of harmine and DMT is an innovative approach that may pave the way towards a safe, rapid-acting, and patient-oriented administration of DMT/harmine for the treatment of affective disorders. Clinical Trial Registration: clinicaltrials.gov, identifier NCT04716335.

3.
Eur J Pharm Biopharm ; 189: 133-151, 2023 Aug.
Article de Anglais | MEDLINE | ID: mdl-37230292

RÉSUMÉ

Porous materials are ubiquitous and exhibit properties suitable for depositing therapeutic compounds. Drug loading in porous materials can protect the drug, control its release rate, and improve its solubility. However, to achieve such outcomes from porous delivery systems, effective incorporation of the drug in the internal porosity of the carrier must be guaranteed. Mechanistic knowledge of the factors influencing drug loading and release from porous carriers allows rational design of formulations by selecting a suitable carrier for each application. Much of this knowledge exists in research areas other than drug delivery. Thus, a comprehensive overview of this topic from the drug delivery aspect is warranted. This review aims to identify the loading processes and carrier characteristics influencing the drug delivery outcome with porous materials. Additionally, the kinetics of drug release from porous materials are elucidated, and the common approaches to mathematical modeling of these processes are outlined.


Sujet(s)
Vecteurs de médicaments , Systèmes de délivrance de médicaments , Préparations pharmaceutiques , Porosité , Systèmes de délivrance de médicaments/méthodes , Solubilité , Libération de médicament
4.
Eur J Pharm Biopharm ; 165: 22-30, 2021 Aug.
Article de Anglais | MEDLINE | ID: mdl-33971274

RÉSUMÉ

Drug delivery to the colon offers great promise for local treatment of colonic diseases as it allows bypassing systemic absorption in the small intestine, thereby increasing luminal drug concentrations in the colon. The primary objective of this in vivo pharmaco-scintigraphy study was to assess the colon drug targeting accuracy of a metronidazole benzoate colonic drug delivery system intended for local treatment of Clostridioides difficile infections. Additionally, it was assessed if the concept of mucoadhesion would increase colonic residence time and promote higher drug bioavailability. Two different capsule formulations were designed and tested in healthy human subjects. Capsules contained either non-mucoadhesive (NM) or mucoadhesive (M) microgranules, both loaded with 100 mg metronidazole benzoate (antibiotic prodrug) and 5 mg samarium oxide (scintigraphy tracer). Filled capsules were coated with a colonic-targeting technology consisting of two functional layers, which allow for accelerated drug release mediated by the intestinal pH in combination with colonic bacteria. Coated capsules were neutron-activated to yield the radioisotope 153Sm prior to administration to 18 healthy subjects. Gamma-scintigraphy imaging was combined with the measurement of drug plasma levels. Formulation NM showed high colon-targeting accuracy. Initial capsule disintegration within the targeted ileocolonic region was observed in 8 out of 9 subjects (89%) with colonic arrival times in the range of 3.5-12 h and reduced systemic exposure. In contrast, the mucoadhesive formulation M showed some inconsistency regarding the site of initial capsule disintegration (targeting accuracy 56%). Variability of drug release was attributed to self-adhesion and agglomeration of the mucoadhesive microparticles within the capsule. Accurate ileocolonic delivery of metronidazole-loaded microgranules was achieved following oral administration of colonic-targeted capsules. Delayed drug release from NM microparticles in the colon leads to a reduced systemic exposure compared to immediate-release data from literature and presumably elevated drug concentrations in the colonic lumen. This approach offers promising options for the local treatment of colonic diseases.


Sujet(s)
Côlon/imagerie diagnostique , Vecteurs de médicaments/composition chimique , Muqueuse intestinale/imagerie diagnostique , Métronidazole/administration et posologie , Administration par voie orale , Adulte , Biodisponibilité , Capsules , Microparticules membranaires , Côlon/métabolisme , Côlon/microbiologie , Libération de médicament , Entérocolite pseudomembraneuse/traitement médicamenteux , Femelle , Volontaires sains , Humains , Muqueuse intestinale/métabolisme , Muqueuse intestinale/microbiologie , Mâle , Métronidazole/pharmacocinétique , Adulte d'âge moyen , Oxydes/administration et posologie , Traceurs radioactifs , Scintigraphie , Samarium/administration et posologie , Jeune adulte
5.
Children (Basel) ; 8(3)2021 Mar 05.
Article de Anglais | MEDLINE | ID: mdl-33807822

RÉSUMÉ

There is a high unmet medical need for child-appropriate oral dosage forms. The acceptability of a novel placebo orally dispersible tablet formulation (pODT) was therefore evaluated. Monolithic tablets contain an inorganic calcium carbonate/calcium phosphate carrier material as the main excipient. They were assessed in a cross-sectional acceptability study. The 40 child participants were between 2 to 5 years and 6 to 10 years old. One pODT with 5 mm diameter was administered to each participating child by placement on the tongue or into the buccal cavity. Parents were asked to complete a questionnaire together with the study personnel. The spontaneous reactions of the children were recorded. The ease of administration and children's acceptance of the tablet was rated by research staff on a 4-point acceptability scale and by parents on a 5-point Likert scale. The older subjects answered how they had liked the pODT by pointing to the appropriate face of a Facial Hedonic Scale. pODT had very high acceptability as 93% of parents, and all questioned children reported the formulation to be acceptable or very acceptable. Staff reported administering pODT in these children without problems. None of the children showed distress on receipt of pODT. We conclude that the proposed child-friendly dosage form provides a convenient option for oral drug administration and is expected to enhance drug-adherence in pediatric patients.

6.
Pharmaceutics ; 13(3)2021 Mar 17.
Article de Anglais | MEDLINE | ID: mdl-33803049

RÉSUMÉ

Amorphous solid dispersions (ASDs) are a promising drug-delivery strategy to overcome poor solubility through formulation. Currently, the understanding of drug absorption mechanisms from ASDs in humans is incomplete. Aiming to gain insights in this matter, we conducted a randomized cross-over design open-label clinical study (NCT03886766) with 16 healthy male volunteers in an ambulatory setting, using micro-dosed efavirenz as a model drug. In three phases, subjects were administered (1) solid ASD of efavirenz 50 mg or (2) dissolved ASD of efavirenz 50 mg or (3) a molecular solution of efavirenz 3 mg (non-ASD) as a control in block-randomized order. Endpoints were the pharmacokinetic profiles (efavirenz plasma concentration vs. time curves) and derived pharmacokinetic parameters thereof (AUC0-t, Cmax, tmax, and ka). Results showed that the dissolved ASD (intervention 2) exhibited properties of a supersaturated solution (compared to aqueous solubility) with rapid and complete absorption of the drug from the drug-rich particles. All interventions showed similar AUC0-t and were well tolerated by subjects. The findings highlight the potential of particle forming ASDs as an advanced drug-delivery system for poorly soluble drugs and provide essential insights into underlying mechanisms of ASD functioning in humans, partially validating current conceptual models.

7.
Clin Pharmacol Ther ; 109(6): 1505-1516, 2021 06.
Article de Anglais | MEDLINE | ID: mdl-33336382

RÉSUMÉ

Metamizole is an analgesic and antipyretic drug used intensively in certain countries. Previous studies have shown that metamizole induces cytochrome (CYP) 2B6 and possibly CYP3A4. So far, it is unknown whether metamizole induces additional CYPs and by which mechanism. Therefore, we assessed the activity of 6 different CYPs in 12 healthy male subjects before and after treatment with 3 g of metamizole per day for 1 week using a phenotyping cocktail approach. In addition, we investigated whether metamizole induces CYPs by an interaction with the constitutive androstane receptor (CAR) or the pregnane X receptor (PXR) in HepaRG cells. In the clinical study, we confirmed a moderate induction of CYP2B6 (decrease in the efavirenz area under the plasma concentration time curve (AUC) by 79%) and 3A4 (decrease in the midazolam AUC by 68%) by metamizole. In addition, metamizole weakly induced CYP2C9 (decrease in the flurbiprofen AUC by 22%) and moderately CYP2C19 (decrease in the omeprazole AUC by 66%) but did not alter CYP2D6 activity. In addition, metamizole weakly inhibited CYP1A2 activity (1.79-fold increase in the caffeine AUC). We confirmed these results in HepaRG cells, where 4-MAA, the principal metabolite of metamizole, induced the mRNA expression of CYP2B6, 2C9, 2C19, and 3A4. In HepaRG cells with a stable knockout of PXR or CAR, we could demonstrate that CYP induction by 4-MAA depends on CAR and not on PXR. In conclusion, metamizole is a broad CYP inducer by an interaction with CAR and an inhibitor of CYP1A2. Regarding the widespread use of metamizole, these findings are of substantial clinical relevance.


Sujet(s)
Anti-inflammatoires non stéroïdiens/pharmacologie , Inhibiteurs du cytochrome P-450 CYP1A2/pharmacologie , Cytochrome P-450 CYP1A2/génétique , Inducteurs des enzymes du cytochrome P-450/pharmacologie , Cytochrome P-450 enzyme system/biosynthèse , Métamizole sodique/pharmacologie , Induction enzymatique/effets des médicaments et des substances chimiques , Adulte , Aire sous la courbe , Lignée cellulaire , Récepteur constitutif des androstanes , Cytochrome P-450 CYP2B6/biosynthèse , Cytochrome P-450 CYP2B6/génétique , Cytochrome P-450 CYP2C9/biosynthèse , Cytochrome P-450 CYP2C9/génétique , Cytochrome P-450 enzyme system/génétique , Interactions médicamenteuses , Femelle , Génotype , Volontaires sains , Humains , Mâle , Récepteur du prégnane X/antagonistes et inhibiteurs , Récepteur du prégnane X/génétique , Récepteurs cytoplasmiques et nucléaires/antagonistes et inhibiteurs , Récepteurs cytoplasmiques et nucléaires/génétique , Jeune adulte
8.
Pharmaceutics ; 12(8)2020 Aug 15.
Article de Anglais | MEDLINE | ID: mdl-32824155

RÉSUMÉ

Despite the wide-spread use of liposomal drug delivery systems, application of these systems for oral purposes is limited due to their large-scale formulation and storage issues. Proliposomes are one of the formulation approaches for achieving solid powders that readily form liposomes upon hydration. In this work, we investigated a dry powder formulation of a model low-soluble drug with phospholipids loaded in porous functionalized calcium carbonate microparticles. We characterized the liposome formation under conditions that mimic the different gastrointestinal stages and studied the factors that influence the dissolution rate of the model drug. The liposomes that formed upon direct contact with the simulated gastric environment had a capacity to directly encapsulate 25% of the drug in situ. The emerged liposomes allowed complete dissolution of the drug within 15 min. We identified a negative correlation between the phospholipid content and the rate of water uptake. This correlation corroborated the results obtained for the rate of dissolution and liposome encapsulation efficiency. This approach allows for the development of solid proliposomal dosage formulations, which can be scaled up with regular processes.

9.
Small ; 16(31): e2000746, 2020 08.
Article de Anglais | MEDLINE | ID: mdl-32567135

RÉSUMÉ

Metal-based nanoparticles are clinically used for diagnostic and therapeutic applications. After parenteral administration, they will distribute throughout different organs. Quantification of their distribution within tissues in the 3D space, however, remains a challenge owing to the small particle diameter. In this study, synchrotron radiation-based hard X-ray tomography (SRµCT) in absorption and phase contrast modes is evaluated for the localization of superparamagnetic iron oxide nanoparticles (SPIONs) in soft tissues based on their electron density and X-ray attenuation. Biodistribution of SPIONs is studied using zebrafish embryos as a vertebrate screening model. This label-free approach gives rise to an isotropic, 3D, direct space visualization of the entire 2.5 mm-long animal with a spatial resolution of around 2 µm. High resolution image stacks are available on a dedicated internet page (http://zebrafish.pharma-te.ch). X-ray tomography is combined with physico-chemical characterization and cellular uptake studies to confirm the safety and effectiveness of protective SPION coatings. It is demonstrated that SRµCT provides unprecedented insights into the zebrafish embryo anatomy and tissue distribution of label-free metal oxide nanoparticles.


Sujet(s)
Nanoparticules de magnétite , Nanoparticules métalliques , Animaux , Oxydes , Distribution tissulaire , Tomodensitométrie , Danio zébré
10.
Ther Umsch ; 77(1): 24-28, 2020.
Article de Allemand | MEDLINE | ID: mdl-32486991

RÉSUMÉ

Abuse deterrent drug formulations for opioids Abstract. Misuse of opioids is an increasing problem. Significant medical and social consequences including overdose-related deaths have led to the declaration of an "opioid crisis". The present review article discusses the extent of the problem with a special focus on the situation in Switzerland. Measures are proposed including training of health care providers, regulatory intervention and technical solutions such as the design of abuse-deterrent formulations.


Sujet(s)
Analgésiques morphiniques/usage thérapeutique , Troubles liés aux opiacés/prévention et contrôle , Préparation de médicament , Humains , Suisse
11.
Pharmaceutics ; 12(6)2020 May 29.
Article de Anglais | MEDLINE | ID: mdl-32485803

RÉSUMÉ

Dissolution and disintegration of solid dosage forms such as multiple-layer tablet with different active ingredients depend on formulation and properties used in the formulations, and it may sometimes result in counterintuitive release kinetics. In this manuscript, we investigate the behavior of combined acetylsalicylic acid and mefenamic acid bi- and triple-layer formulations. We show that the simulation model with a cellular automata predicted the impact of the inert layer between the different active ingredients on each drug release and provide a good agreement with the experimental results. Also, it is shown that the analysis based on the Noyes-Whitney equation in combination with a cellular automata-supported dissolution and disintegration numerical solutions explain the nature of the unexpected effects. We conclude that the proposed simulation approach is valuable to predict the influence of material attributes and process parameters on drug release from multicomponent and multiple-layer pharmaceutical tablets and to help us develop the drug product formulation.

12.
Drug Deliv ; 27(1): 110-127, 2020 Dec.
Article de Anglais | MEDLINE | ID: mdl-31885288

RÉSUMÉ

Amorphous solid dispersions (ASDs) can increase the oral bioavailability of poorly soluble drugs. However, their use in drug development is comparably rare due to a lack of basic understanding of mechanisms governing drug liberation and absorption in vivo. Furthermore, the lack of a unified nomenclature hampers the interpretation and classification of research data. In this review, we therefore summarize and conceptualize mechanisms covering the dissolution of ASDs, formation of supersaturated ASD solutions, factors responsible for solution stabilization, drug uptake from ASD solutions, and drug distribution within these complex systems as well as effects of excipients. Furthermore, we discuss the importance of these findings on the development of ASDs. This improved overall understanding of these mechanisms will facilitate a rational ASD formulation development and will serve as a basis for further mechanistic research on drug delivery by ASDs.


Sujet(s)
Excipients/composition chimique , Pharmacocinétique , Technologie pharmaceutique/méthodes , Biodisponibilité , Cristallisation , Préparations à action retardée , Libération de médicament , Stabilité de médicament , Solubilité , Tensioactifs/composition chimique
13.
Int J Pharm ; 573: 118827, 2020 Jan 05.
Article de Anglais | MEDLINE | ID: mdl-31756443

RÉSUMÉ

Uniform drug distribution within fast disintegrating tablets is a key quality measure to ensure a reliable, steady, and targeted release of the contained active pharmaceutical ingredients. In this work, the drug particle distribution in mini-tablets was studied with synchrotron phase contrast X-ray microtomography. Mini-tablets had a weight of 9.5 mg and a drug load from 2.5% to 20%. Moxidectin, a drug used for treatment of parasitic infections, was used as a model compound. Drug content covered a range from 91% to 121% of the target dose. A linear iterative clustering (SLIC) superpixel method was used for segmentation, analysis, and visualization of the spatial distribution of individual tablet components (i.e., pores, excipients, and drug). Results show that the drug was not uniformly distributed within the tablet, revealing an increasing drug load towards the tablets' outer boundaries and thus indicative of a radial displacement of drug particles during compaction. The presented method can be used for the quantitative analysis of drug content and drug distribution within pharmaceutical tablets, allowing for the optimization of fast disintegrating formulations. The results also affirm that that drug loads up to 20% will not lead to segregation for moxidectin.


Sujet(s)
Chimie pharmaceutique/méthodes , Préparation de médicament , Systèmes de délivrance de médicaments , Traitement d'image par ordinateur , Microtomographie aux rayons X/méthodes , Anthelminthiques/composition chimique , Chimie pharmaceutique/instrumentation , Analyse de regroupements , Excipients/composition chimique , Macrolides/administration et posologie , Macrolides/composition chimique , Solubilité , Synchrotrons , Comprimés , Microtomographie aux rayons X/instrumentation
14.
Clin Infect Dis ; 70(6): 1193-1201, 2020 03 03.
Article de Anglais | MEDLINE | ID: mdl-31044235

RÉSUMÉ

BACKGROUND: Preventive chemotherapy is the main strategy to control soil-transmitted helminth (STH) infections. Albendazole and mebendazole are ubiquitously used, but they are not sufficiently effective against Trichuris trichiura. Moxidectin might be a useful addition to the small drug armamentarium. However, the optimal dosage of moxidectin alone and in combination with albendazole against T. trichiura and other STHs has not yet been determined. METHODS: A Phase II, randomized, placebo-controlled, dose-finding trial was conducted in 2 secondary schools on Pemba Island, Tanzania. Using a computer-generated list, T. trichiura-infected adolescents were randomly assigned to 7 treatment arms: 8, 16, or 24 mg of moxidectin monotherapy; 8, 16, or 24 mg of moxidectin plus 400 mg of albendazole combination therapy; or placebo. The primary outcome was cure rate (CR) against T. trichiura, analyzed 13 to 20 days after treatment by quadruple Kato-Katz thick smears. RESULTS: A total of 290 adolescents were enrolled (41 or 42 per arm). CRs against T. trichiura were 43, 46, and 44% for 8, 16, and 24 mg of moxidectin alone, respectively; 60, 62, and 66% for the same moxidectin dosages plus 400 mg of albendazole, respectively; and 12% for placebo. The moxidectin-albendazole arms also revealed higher CRs and egg reduction rates against hookworm than the monotherapy arms. Moxidectin and its combination with albendazole were well tolerated. CONCLUSIONS: Moxidectin-albendazole is superior to moxidectin. There is no benefit of using doses above 8 mg, which is the recommended dose for onchocerciasis. The moxidectin-albendazole combination of 8 mg plus 400 mg should be investigated further to develop recommendations for appropriate control of STH infections. CLINICAL TRIALS REGISTRATION: NCT03501251.


Sujet(s)
Anthelminthiques , Trichocéphalose , Adolescent , Albendazole/effets indésirables , Animaux , Anthelminthiques/effets indésirables , Fèces , Humains , Macrolides , Tanzanie , Trichocéphalose/traitement médicamenteux , Trichuris
15.
Br J Clin Pharmacol ; 86(2): 352-361, 2020 02.
Article de Anglais | MEDLINE | ID: mdl-31657866

RÉSUMÉ

AIMS: We compared the phenotyping metrics of a combination capsule formulation to its individual components of the newly composed Basel phenotyping cocktail. Moreover, we investigated a reduced sampling regimen for clinical applications. METHODS: We performed in vitro experiments and a crossover pharmacokinetic study in twelve healthy male subjects to compare the Basel phenotyping cocktail capsule containing 6 cytochrome P450 (CYP) probe drugs with individual administration of the same drugs. Parent compounds and selected metabolites were determined by liquid chromatography-tandem mass spectrometry. Metabolic ratios (MR) for are under the curve (AUC) and single time point measurements and their correlation were determined. RESULTS: Experiments with human liver microsomes and primary human hepatocytes in 3D co-culture confirmed that flurbiprofen is a suitable CYP2C9 substrate. Both cocktail formulations (capsule and individual probe drug administration) were well-tolerated and yielded reproducible MRs, which were almost identical. Correlations between single time point ratios and the corresponding AUC ratios depended on the sampling time point and the concentration time curve of the probe drugs. The MR of the capsule (Spearman rank correlation coefficient, Rs : 0.77-0.97) as well as the individual components (Rs : 0.69-0.99) correlated best at 6 h post-treatment considering all 6 CYPs. Moreover, the 2-h time points of the capsule agreed suitably with the AUC; however, the MR of omeprazole could not be determined for 10 out of 12 subjects. CONCLUSION: The capsule is easy to swallow, well tolerated and provides reliable estimates for CYP activity. The optimal sampling point for the capsule formulation is 6 h after intake.


Sujet(s)
Cytochrome P-450 enzyme system , Préparations pharmaceutiques , Adulte , Chromatographie en phase liquide , Cytochrome P-450 enzyme system/génétique , Humains , Mâle , Microsomes du foie , Phénotype
16.
Pharmaceutics ; 11(1)2019 Jan 15.
Article de Anglais | MEDLINE | ID: mdl-30650593

RÉSUMÉ

Accurate analysis of intraparticle distribution of substances within porous drug carriers is important to optimize loading and subsequent processing. Mercury intrusion porosimetry, a common technique used for characterization of porous materials, assumes cylindrical pore geometry, which may lead to misinterpretation. Therefore, imaging techniques such as focused ion beam scanning electron microscopy (FIB-SEM) help to better interpret these results. The purpose of this study was to investigate the differences between mercury intrusion and scanning electron microscopy and to identify the limitations of each method. Porous microparticles, functionalized calcium carbonate, were loaded with bovine serum albumin and dipalmitoylphosphatidylcholine (DPPC) by solvent evaporation and results of the pore size distribution obtained by both methods were compared. The internal structure of the novel pharmaceutical excipient, functionalized calcium carbonate, was revealed for the first time. Our results demonstrated that image analysis provides a closer representation of the material distribution since it was possible to discriminate between blocked and filled pores. The physical nature of the loaded substances is critical for the deposition within the pores of functionalized calcium carbonate. We conclude, that a combination of mercury intrusion porosimetry and focused ion beam scanning electron microscopy allows for a reliable analysis of sub-micron porous structures of particulate drug carriers.

17.
Drug Dev Ind Pharm ; 45(2): 222-230, 2019 Feb.
Article de Anglais | MEDLINE | ID: mdl-30260721

RÉSUMÉ

Tablets for oral suspension (TOS) present a convenient alternative dosage form to conventional tablets. Dispersed in a glass of water or on a spoon, such tablets can be easily administered, which can become beneficial for pediatric or geriatric patients. The novel excipient functionalized calcium carbonate (FCC), consisting of calcium carbonate and calcium phosphate, has already shown to be suitable to produce orally disintegrating placebo tablets. In this study, the influence of formulation composition on disintegration time in water and artificial saliva was investigated using caffeine and oxantel pamoate as model drugs, reflecting BCS class 1 and BCS class 4, respectively. The optimized formulation for each model drug underwent a stress test. The results show that the drug content in DTs was not influenced by FCC under stressed conditions, however the disintegration and dissolution performance was affected by temperature and humidity. It can be concluded that it was possible to produce TOS characterized by rapid disintegration complemented by high physical stability of the tablets and chemical stability of the drug.


Sujet(s)
Caféine/composition chimique , Carbonate de calcium/composition chimique , Pamoate de pyrantel/analogues et dérivés , Administration par voie orale , Caféine/administration et posologie , Préparation de médicament , Stabilité de médicament , Microscopie électronique à balayage , Pamoate de pyrantel/administration et posologie , Pamoate de pyrantel/composition chimique , Salive/composition chimique , Solubilité , Suspensions , Comprimés
18.
Pharmaceutics ; 10(4)2018 Dec 03.
Article de Anglais | MEDLINE | ID: mdl-30513888

RÉSUMÉ

Manufacturing parameters may have a strong impact on the dissolution and disintegration of solid dosage forms. In line with process analytical technology (PAT) and quality by design approaches, computer-based technologies can be used to design, control, and improve the quality of pharmaceutical compacts and their performance. In view of shortcomings of computationally intensive finite-element or discrete-element methods, we propose a modeling and simulation approach based on numerical solutions of the Noyes-Whitney equation in combination with a cellular automata-supported disintegration model. The results from in vitro release studies of mefenamic acid formulations were compared to calculated release patterns. In silico simulations with our disintegration model showed a high similarity of release profile as compared to the experimental evaluation. Furthermore, algorithmically created virtual tablet structures were in good agreement with microtomography experiments. We conclude that the proposed computational model is a valuable tool to predict the influence of material attributes and process parameters on drug release from tablets.

19.
Lancet Infect Dis ; 18(8): 864-873, 2018 08.
Article de Anglais | MEDLINE | ID: mdl-29858149

RÉSUMÉ

BACKGROUND: The recommended anthelmintics show low efficacy in a single-dose regimen against Trichuris trichiura. Moxidectin, a new treatment for river blindness, might complement the drug armamentarium for the treatment and control of soil-transmitted helminthiasis. However, its efficacy against T trichiura has not yet been studied. The aim of the study was to assess the efficacy of moxidectin alone and in co-administrations against T trichiura infection. METHODS: A randomised, single-blind, non-inferiority trial was done in two primary schools and one secondary school in Pemba, Tanzania. Adolescents aged 12-18 years who tested positive for T trichiura were randomly assigned (5:5:3:3) with a computer-generated sequence to receive moxidectin (8 mg) plus albendazole (400 mg), albendazole (400 mg) plus oxantel pamoate (25 mg/kg; reference treatment), moxidectin (8 mg) plus tribendimidine (200 mg or 400 mg), or moxidectin (8 mg) alone. Study group assignments were masked from participants and laboratory technicians. The primary outcome was non-inferiority with a 2 percentage point margin for egg reduction rate (ERR) against T trichiura assessed as the relative change in the geometric mean egg counts from baseline to 14-21 days after treatment with the Kato-Katz method, based on the available case population. Cure rates (CR) and tolerability (assessed 3, 24, and 48 h post treatment) were secondary outcomes. The study is registered at ISRCTN (number 20398469) and is closed to accrual. FINDINGS: 701 students were enrolled between April 1, and Aug 7, 2017. Primary outcome data were available for 634 students. We observed ERRs of 98·5% for moxidectin plus albendazole and 99·8% for albendazole plus oxantel pamoate, resulting in an absolute difference of -1·2 percentage points (95% CI -1·8 to -0·8), meeting the non-inferiority margin. 100 (51%) of 197 students receiving moxidectin plus albendazole and 166 (83%) of 200 receiving albendazole plus oxantel pamoate were cured, indicating a difference of 32 percentage points (odds ratio 5·3, 95% CI 3·3 to 8·7). ERRs were 91·6% for moxidectin-tribendimidine and 83·2% for moxidectin. Only mild adverse events (mainly headache and stomach pain) were reported. The largest number of adverse events (126 [20%] of 632 students) was observed 24 h post treatment, with no difference among the individual treatment arms (ranging from 23 [19%] of 118 students treated with moxidectin to 38 [19%] of 199 with moxidectin plus albendazole). INTERPRETATION: Moxidectin plus albendazole showed non-inferiority to albendazole plus oxantel pamoate in terms of ERR; however, albendazole plus oxantel pamoate showed a considerably higher cure rate. Dose-optimisation studies with moxidectin and moxidectin plus albendazole should be considered since the efficacy of the dose used for the treatment of onchocerciasis (8 mg) in this study might not be optimal for the treatment of T trichiura infections. FUNDING: Thrasher Foundation.


Sujet(s)
Albendazole/administration et posologie , Anthelminthiques/administration et posologie , Association de médicaments , Macrolides/administration et posologie , Phénylènediamines/administration et posologie , Pamoate de pyrantel/analogues et dérivés , Trichocéphalose/traitement médicamenteux , Administration par voie orale , Adolescent , Animaux , Enfant , Femelle , Humains , Mâle , Mébendazole , Pamoate de pyrantel/administration et posologie , Méthode en simple aveugle , Trichuris/isolement et purification
20.
Lancet Infect Dis ; 18(7): 729-737, 2018 07.
Article de Anglais | MEDLINE | ID: mdl-29673735

RÉSUMÉ

BACKGROUND: Albendazole and mebendazole are commonly used to control hookworm, but have shortcomings in their efficacy profiles. We assessed whether triple drug therapy (TDT) with albendazole, pyrantel pamoate, and oxantel pamoate was more effective than the co-administration of two drugs for the treatment of hookworm infections. METHODS: A randomised, single-blind trial was done from Sept 27 until Nov 17, 2017, in Laos. Children (6-15 years) from six schools were invited to participate. Hookworm-positive children were randomly assigned (2:2:1:1) by a computer stratified list (block sizes of six and 12) to TDT with albendazole (400 mg), pyrantel pamoate (20 mg/kg), and oxantel pamoate (20 mg/kg); albendazole plus oxantel pamoate; pyrantel pamoate plus oxantel pamoate; or mebendazole (500 mg) combined with both pyrantel pamoate and oxantel pamoate (used as proof of concept to compare the two TDTs). Two stool samples were collected at baseline and follow-up (17-30 days after treatment) and analysed with the Kato-Katz method. The primary outcome was the proportion of hookworm egg-negative children at follow-up in all Kato-Katz slides (cure rate [CR]) in the TDT with albendazole, pyrantel pamoate, and oxantel pamoate group compared with the albendazole plus oxantel pamoate and pyrantel pamoate plus oxantel pamoate groups. Secondary outcomes were tolerability 3 h and 24 h after treatment, egg reduction rates (ERRs) against hookworm, and efficacy against concomitant soil-transmitted helminth infections. Participating children and field and laboratory technicians were masked to treatment allocation. All children with follow-up data were included in the primary analysis. This trial is registered with ClinicalTrials.gov, number NCT03278431. FINDINGS: 1529 children were assessed for eligibility, of whom 533 provided complete baseline data and 414 provided complete outcome data. The CR was higher for the TDT albendazole, pyrantel pamoate, and oxantel pamoate (116 [84%] of 138) than with albendazole plus oxantel pamoate (73 [53%] of 138; odds ratio 4·7, 95% CI 2·7-8·3; p<0·0001) and pyrantel pamoate plus oxantel pamoate (36 [52%] of 69; 4·8, 2·5-9·3; p<0·0001). The geometric ERR of the TDT albendazole, pyrantel pamoate, and oxantel pamoate (99·9%) was higher than that for albendazole plus oxantel pamoate (99·0%; difference in ERR 0·9 percentage points, 95% CI 0·5-1·4), and pyrantel pamoate plus oxantel pamoate (99·2%; 0·7 percentage points, 0·3-1·3). Adverse events were reported by six (1%) children 3 h and none 24 h after treatment, without any difference across treatment groups. INTERPRETATION: TDT with albendazole, pyrantel pamoate, and oxantel pamoate could make a difference, in particular in the context of soil-transmitted helminth elimination. Pyrantel pamoate might be a useful alternative to prevent benzimidazole resistance; however, larger trials are needed to confirm this finding. FUNDING: Swiss National Science Foundation.


Sujet(s)
Albendazole/usage thérapeutique , Anthelminthiques/usage thérapeutique , Association médicamenteuse , Infections à ankylostomes/traitement médicamenteux , Mébendazole/usage thérapeutique , Pamoate de pyrantel/analogues et dérivés , Pamoate de pyrantel/usage thérapeutique , Adolescent , Ancylostomatoidea/effets des médicaments et des substances chimiques , Animaux , Enfant , Femelle , Humains , Laos , Mâle , Méthode en simple aveugle , Résultat thérapeutique
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