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1.
Malar J ; 22(1): 76, 2023 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-36870966

RESUMO

BACKGROUND: The World Health Organization recommends parasitological confirmation of all suspected malaria cases by microscopy or rapid diagnostic tests (RDTs) before treatment. These conventional tools are widely used for point-of-care diagnosis in spite of their poor sensitivity at low parasite density. Previous studies in Ghana have compared microscopy and RDT using standard 18S rRNA PCR as reference with varying outcomes. However, how these conventional tools compare with ultrasensitive varATS qPCR has not been studied. This study, therefore, sought to investigate the clinical performance of microscopy and RDT assuming highly sensitive varATS qPCR as gold standard. METHODS: 1040 suspected malaria patients were recruited from two primary health care centers in the Ashanti Region of Ghana and tested for malaria by microscopy, RDT, and varATS qPCR. The sensitivity, specificity, and predictive values were assessed using varATS qPCR as gold standard. RESULTS: Parasite prevalence was 17.5%, 24.5%, and 42.1% by microscopy, RDT, and varATS qPCR respectively. Using varATS qPCR as the standard, RDT was more sensitive (55.7% vs 39.3%), equally specific (98.2% vs 98.3%), and reported higher positive (95.7% vs 94.5%) and negative predictive values (75.3% vs 69.0%) than microscopy. Consequently, RDT recorded better diagnostic agreement (kappa = 0.571) with varATS qPCR than microscopy (kappa = 0.409) for clinical detection of malaria. CONCLUSIONS: RDT outperformed microscopy for the diagnosis of Plasmodium falciparum malaria in the study. However, both tests missed over 40% of infections that were detected by varATS qPCR. Novel tools are needed to ensure prompt diagnosis of all clinical malaria cases.


Assuntos
Malária Falciparum , Malária , Humanos , Microscopia , Reação em Cadeia da Polimerase , Gana
2.
J Drug Deliv Sci Technol ; 84: 104486, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37123173

RESUMO

Inhalation phage therapy is proposed as a replacement approach for antibiotics in the treatment of pulmonary bacterial infections. This study investigates phage therapy on bacterial pneumonia in patients with moderate to severe COVID-19 via the inhalation route. In this double-blind clinical trial, 60 patients with positive COVID-19 hospitalized in three central Mazandaran hospitals were chosen and randomly divided into two intervention and control groups. Standard country protocol drugs plus 10 mL of phage suspension every 12 h with a mesh nebulizer was prescribed for 7 days in the intervention group. The two groups were compared in terms of O2Sat, survival rate, severe secondary pulmonary bacterial infection and duration of hospitalization. Comparing the results between the intervention and control group, in terms of the trend of O2Sat change, negative sputum culture, no fever, no dyspnea, duration of hospitalization, duration of intubation and under ventilation, showed that the difference between these two groups was statistically different (P value < 0.05). In conclusion, inhalation phage therapy may have a potential effect on secondary infection and in the outcome of COVID-19 patients. However, more clinical trials with control confounding factors are needed to further support this concept.

3.
AAPS PharmSciTech ; 24(8): 222, 2023 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-37935931

RESUMO

This study reports on the synthesis of Mn1 - xZnxFe2O4 (Mn, Zn ferrite) magnetic nanoparticles (MNPs) as drug delivery carriers for effective therapeutic outcomes. The MNPs were prepared using the coprecipitation method, and their magnetic properties were investigated based on their composition. Among the compositions tested, Mn0.8Zn0.2Fe2O4 MNPs exhibited superparamagnetic properties with a saturation magnetization moment of 34.6 emu/g at room temperature (25°C). To enhance the water solubility of curcumin (Cur), known for its hydrophobic nature, it was successfully loaded onto alginate (Alg)/chitosan (Chit)@Mn0.8Zn0.2Fe2O4 nanoparticles (NPs). The nanocomposite was characterized by field emission scanning electron microscopy (FE-SEM) which revealed a particle size of approximately 20 nm. The crystalline structure of the NPs was analyzed using X-ray diffraction, while Fourier-transform infrared (FTIR), energy-dispersive X-ray, and map analysis techniques were employed for further characterization. In terms of drug release, there was an initial burst release of Cur (around 18%) within the first hour, followed by a slower release (approximately 61%) over the next 36 h. The anti-tumor properties of the Cur-loaded NPs were evaluated using the Methyl Thiazol Tetrazolium (MTT) assay and quantitative real-time polymerase chain reaction. The MTT assay confirmed a higher cytotoxic effect of Cur-loaded Alg/Chit@Mn0.8Zn0.2Fe2O4 NPs on the MCF-7 breast cancer cell line compared to free Cur, highlighting the significance of incorporating Cur into nano-sized carrier systems.


Assuntos
Neoplasias da Mama , Quitosana , Curcumina , Nanopartículas , Humanos , Feminino , Curcumina/farmacologia , Curcumina/química , Quitosana/química , Alginatos/química , Neoplasias da Mama/tratamento farmacológico , Portadores de Fármacos/química , Nanopartículas/química , Zinco , Tamanho da Partícula
4.
Pharm Dev Technol ; 27(1): 63-71, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34939892

RESUMO

Pistacia atlantica has an anti-cancer effect due to its essential oil which is the major constituent of P. atlantica. Unfortunately, this essential oil evaporates easily and makes it less effective. The current research, therefore, aimed to improve the anti-cancer effect of P. atlantica essential oil (PAEO) in solid lipid nanoparticles (SLN). The chemical components of PAEO were assessed by gas chromatography. PAEO-SLNs were prepared by the probe-ultrasonication method, and their particle size, polydispersity index and zeta potential were determined. Encapsulation Efficiency (EE%) and Loading Capacity (LC%) of formulations was also calculated. Transmission electron microscopy was employed to determine the morphology of optimal formulation (PAEO-SLN4). Furthermore, the anticancer effects of PAEO-SLN4 against MDA-MB-231 cells were evaluated by cellular assays. The results showed that the type of surfactant and loading of the essential oil had a significant effect on size distribution, zeta potential and the polydispersity index. The encapsulation efficiency (EE%) and loading capacity for PAEO-SLN4 were 97.3% and 9.6%, respectively. The cellular assay demonstrates that PAEO-SLN4 could lead MDA-MB-231 cells to apoptosis. The findings also revealed that PAEO-SLN4 can stimulate apoptosis in MDA-MB-231 cells more than the placebo and free PAEO thereby indicating PAEO-SLN4 to be beneficial in breast cancer treatment.


Assuntos
Neoplasias da Mama , Nanopartículas , Óleos Voláteis , Pistacia , Apoptose , Neoplasias da Mama/tratamento farmacológico , Linhagem Celular , Feminino , Humanos , Lipossomos , Nanopartículas/química , Óleos Voláteis/farmacologia , Tamanho da Partícula
5.
Pharm Dev Technol ; 27(5): 525-544, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35635506

RESUMO

The bioavailability of drugs is dependent on several factors such as solubility and the administration route. A drug with poor aqueous solubility, therefore, poses challenges with regards to its pharmaceutical advance and ultimately its biological usage. Lipid nanoparticles have been used in pharmaceutical science due to their importance in green chemistry. Their biochemical properties as 'green' materials and biochemical processes as 'green' processes mean they can be environmentally sustainable. Generally, lipid nanoparticles can be employed as carriers for both lipophilic and hydrophilic drugs. The proposed administration route for nanoparticles can present advantages and disadvantages which should be considered by a formulator. Solid lipid nanoparticles (SLNs) and nanostructured lipid carriers (NLCs) are attractive delivery systems because of their ease of manufacture, biocompatibility, biodegradability, and scale-up capacity of formulation constituents. The easy and simple scalability of novel SLNs and nano lipid carriers, along with their various processing procedures, recent developments, limitation and toxicity, formulation optimization and approaches for the manufacture of lipid nanoparticles, lyophilization and drug release are comprehensively discussed in this review. This review also summarizes the research data related to the various preparation methods and excipients used for SLNs and NLCs in recent years.


Assuntos
Nanoestruturas , Portadores de Fármacos/química , Sistemas de Liberação de Medicamentos/métodos , Lipídeos/química , Lipossomos , Nanopartículas/química , Nanoestruturas/química , Tamanho da Partícula
6.
AAPS PharmSciTech ; 23(3): 81, 2022 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-35266075

RESUMO

The present study aimed to formulate atorvastatin niosome (Atrosome) through an ultrasonic technique and to determine its contribution to the extent of wound healing in an animal model. The optimized Atrosome formulation (Atrosome-2) was stable at 4 °C for 3 months. Differential scanning calorimetry (DSC), ATR-Fourier transform infrared spectroscopy (ATR-FTIR), and powder X-ray diffraction (PXRD) analysis revealed that atorvastatin (ATR) was well encapsulated within the niosomes either in a stabilized amorphous form or a molecularly dispersed state. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), and atomic force microscope (AFM) confirmed the spherical nature of the Atrosomes. The optimized formulation showed polydispersity index, particle size, drug encapsulation efficiency (EE%), and zeta potential of 0.457 ± 0.05, 196.33 ± 6.45 nm, 86.15 ± 0.58 %, and - 20.73 ± 0.98 mV, respectively. ATR release from the Atrosome gel followed the first-order kinetic model and showed no cytotoxicity in the in vitro cytotoxicity test. Cell viability (human foreskin fibroblast cell line) was nearly 99%. An excision wound model was also applied in male Wistar rats to examine the in vivo efficacy of the optimized formulation, followed by investigating malondialdehyde (MDA, an end-product of lipid peroxidation), superoxide dismutase (SOD, an endogenous antioxidant), hydroxyproline levels, and glutathione peroxidase (GPx) in skin tissue samples. MDA significantly decreased in the Atrosome gel group after 21 days, while GPx, SOD, and hydroxyproline levels demonstrated an increase. According to histological results, rats receiving Atrosomes were treated effectively faster when compared to the other formulation used.


Assuntos
Lipossomos , Nanopartículas , Animais , Atorvastatina/farmacologia , Varredura Diferencial de Calorimetria , Masculino , Nanopartículas/química , Tamanho da Partícula , Ratos , Ratos Wistar , Cicatrização
7.
AAPS PharmSciTech ; 23(5): 149, 2022 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-35595933

RESUMO

The goal of this experimentation was to increase the cutaneous absorption of venlafaxine HCl (VFX) encapsulated in a niosome (venlasosme) produced by an ultrasonic approach. The impact of the cholesterol:surfactant (Chol:Surf) proportion was examined to modify the venlasosme properties. Photon correlation spectroscopy, powder X-ray diffraction (PXRD), SEM, DSC, and ATR-FTIR spectroscopy were utilized to investigate the solid-state and morphology of VFX in the venlasosme. The studies revealed that increasing the level of Chol in the venlasosme increased the size of the particles. Alterations in the Chol to surfactant ratios (when Chol decreased from 2.5 to 0%) caused the zeta potential enhancement from 7.37 ± 0.67 to 15.53 ± 1.47 mV. The venlasosme with the highest cholesterol concentration (2.5%) had the highest encapsulation efficiency (approximately 63%). PXRD results revealed that VFX in venlasosme was in the amorphous form. The levels of VFX in the cutaneous layers and the receiver compartment were higher for the venlasosme gel than for VFX simple gel in the cutaneous permeability study and showed no cutaneous irritancy in rats. Furthermore, the venlasosme gel demonstrated significant antinociceptive and anti-inflammatory responses when compared to the control groups (VFX simple gel and diclofenac gel). The topical administration of the venlasosme gel also considerably increased the tail-flick and hot-plate response time when compared to the VFX simple gel, control groups, and diclofenac gel (p < 0.05). These findings suggest that niosomes can improve VFX efficacy as an antinociceptive and anti-inflammatory substance by improving the medicaments delivery to the specified site.


Assuntos
Diclofenaco , Lipossomos , Analgésicos , Animais , Anti-Inflamatórios , Colesterol , Dor/tratamento farmacológico , Ratos , Tensoativos , Cloridrato de Venlafaxina
8.
AAPS PharmSciTech ; 22(3): 85, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33650023

RESUMO

In this study, an attempt was made to produce Liqui-Tablets for the first time. This was carried out through the compaction of naproxen Liqui-Pellets. The incentive to convert the novel Liqui-Pellet into Liqui-Tablet was due to the array of inherent advantages of the popular and preferred tablet dosage form. The study showed that naproxen Liqui-Tablet could be successfully produced and the rapid drug release rate (100% drug release ~ 20 min) could be achieved under pH 1.2, where naproxen is insoluble. It was observed that the different pH of the dissolution medium affected the trend of drug release from formulations with varying amounts of liquid vehicle. The order of the fastest drug-releasing formulations was different depending on the pH used. The presence of Neusilin US2 showed considerable enhancement in the drug release rate as well as improving Liqui-Tablet robustness and hardness. Furthermore, images from X-ray micro-tomography displayed a uniform distribution of components in the Liqui-Tablet. The accelerated stability studies showed acceptable stability in terms of dissolution profile.


Assuntos
Composição de Medicamentos/métodos , Naproxeno/administração & dosagem , Naproxeno/síntese química , Tecnologia Farmacêutica/métodos , Administração Oral , Anti-Inflamatórios não Esteroides/administração & dosagem , Anti-Inflamatórios não Esteroides/síntese química , Anti-Inflamatórios não Esteroides/farmacocinética , Formas de Dosagem , Liberação Controlada de Fármacos , Excipientes/administração & dosagem , Excipientes/síntese química , Excipientes/farmacocinética , Naproxeno/farmacocinética , Comprimidos
9.
AAPS PharmSciTech ; 22(5): 170, 2021 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-34085150

RESUMO

A novel nanofiber insert was prepared with a modified electrospinning method to enhance the ocular residence time of ofloxacin (OFX) and to provide a sustained release pattern by covering hydrophilic polymers, chitosan/polyvinyl alcohol (CS/PVA) nanofibers, with a hydrophobic polymer, Eudragit RL100 in layers, and by glutaraldehyde (GA) cross-linking of CS-PVA nanofibers for the treatment of infectious conjunctivitis. The morphology of the prepared nanofibers was studied using scanning electron microscopy (SEM). The average fiber diameter was found to be 123 ± 23 nm for the single electrospun nanofiber with no cross-linking (OFX-O). The single nanofibers, cross-linked for 10 h with GA (OFX-OG), had an average fiber diameter of 159 ± 30 nm. The amount of OFX released from the nanofibers was measured in vitro and in vivo using UV spectroscopy and microbial assay methods against Staphylococcus aureus, respectively. The antimicrobial efficiency of OFX formulated in cross-linked and non-cross-linked nanofibers was affirmed by observing the inhibition zones of Staphylococcus aureus and Escherichia coli. In vivo studies using the OFX nanofibrous inserts on a rabbit eye confirmed a sustained release pattern for up to 96 h. It was found that the cross-linking of the nanofibers by GA vapor could reduce the burst release of OFX from OFX-loaded CS/PVA in one layer and multi-layered nanofibers. In vivo results showed that the AUC0-96 for the nanofibers was 9-20-folds higher compared to the OFX solution. This study thus demonstrates the potential of the nanofiber technology is being utilized to sustained drug release in ocular drug delivery systems.


Assuntos
Resinas Acrílicas/química , Administração Oftálmica , Quitosana/química , Nanofibras/química , Ofloxacino/química , Álcool de Polivinil/química , Resinas Acrílicas/administração & dosagem , Resinas Acrílicas/farmacocinética , Animais , Antibacterianos/química , Química Farmacêutica/métodos , Quitosana/administração & dosagem , Quitosana/farmacocinética , Preparações de Ação Retardada/administração & dosagem , Preparações de Ação Retardada/química , Preparações de Ação Retardada/farmacocinética , Sistemas de Liberação de Medicamentos/métodos , Avaliação Pré-Clínica de Medicamentos/métodos , Escherichia coli/efeitos dos fármacos , Escherichia coli/fisiologia , Nanofibras/administração & dosagem , Ofloxacino/administração & dosagem , Ofloxacino/farmacocinética , Álcool de Polivinil/administração & dosagem , Álcool de Polivinil/farmacocinética , Coelhos , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/fisiologia
10.
AAPS PharmSciTech ; 23(1): 42, 2021 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-34964076

RESUMO

Solubility determination of poorly water-soluble drugs is pivotal for formulation scientists when they want to develop a liquid formulation. Performing such a test with different ratios of cosolvents with water is time-consuming and costly. The scarcity of solubility data for poorly water-soluble drugs increases the importance of developing correlation and prediction equations for these mixtures. Therefore, the aim of the current research is to determine the solubility of acetylsalicylic acid in binary mixtures of ethanol+water at 25 and 37°C. Acetylsalicylic acid is non-stable in aqueous solutions and readily hydrolyze to salicylic acid. So, the solubility of acetylsalicylic acid is measured in ethanolic mixtures by HPLC to follow the concentration of produced salicylic acid as well. Moreover, the solubility of acetylsalicylic acid is modeled using different cosolvency equations. The measured solubility data were also predicted using PC-SAFT EOS model. DSC results ruled out any changes in the polymorphic form of acetylsalicylic acid after the solubility test, whereas XRPD results showed some changes in crystallinity of the precipitated acetylsalicylic acid after the solubility test. Fitting the solubility data to the different cosolvency models showed that the mean relative deviation percentage for the Jouyban-Acree model was less than 10.0% showing that this equation is able to obtain accurate solubility data for acetylsalicylic acid in mixtures of ethanol and water. Also, the predicted data with an average mean relative deviation percentage (MRD%) of less than 29.65% show the capability of the PC-SAFT model for predicting solubility data. A brief comparison of the solubilities of structurally related solutes to acetylsalicylic acid was also provided.


Assuntos
Etanol , Água , Aspirina , Solubilidade , Solventes
11.
Pharm Dev Technol ; 23(2): 183-197, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28985687

RESUMO

Swelling, erosion, deformation, and consolidation properties can affect the performance of cellulose ethers, the most commonly used matrix former in hydrophilic sustained tablet formulations. The present study was designed to comparatively evaluate the swelling, erosion, compression, compaction, and relaxation properties of the cellulose ethers in a comprehensive study using standardised conditions. The interrelationship between various compressional models and the inherent deformation and consolidation properties of the polymers on the derived swelling and erosion parameters are consolidated. The impact of swelling (Kw) on erosion rates (KE) and the inter-relationship between Heckel and Kawakita plasticity constants was also investigated. It is evident from the findings that the increases in both substitution and polymer chain length led to higher Kw, but a lower KE; this was also true for all particle size fractions regardless of polymer grade. Smaller particle size and high substitution levels tend to increase the relative density of the matrix but reduce porosity, yield pressure (Py), Kawakita plasticity parameter (b-1) and elastic relaxation. Both KW versus KE (R2 = 0.949-0.980) and Py versus. b-1 correlations (R2 = 0.820-0.934) were reasonably linear with regards to increasing hydroxypropyl substitution and molecular size. Hence, it can be concluded that the combined knowledge of swelling and erosion kinetics in tandem with the in- and out-of-die compression findings can be used to select a specific polymer grade and further to develop and optimize formulations for oral controlled drug delivery applications.


Assuntos
Celulose/química , Éteres/química , Química Farmacêutica/métodos , Cinética , Tamanho da Partícula , Polímeros/química , Porosidade , Pressão
12.
Drug Dev Ind Pharm ; 41(10): 1682-92, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25496174

RESUMO

The cogrinding technique is one of most effective methods for improving the dissolution of poorly water-soluble drugs and it is superior to other approaches from an economical as well as an environmental standpoint, as the technique does not require any toxic organic solvents. Present work explores the role of d-glucosamine HCl (GL) as a potential excipient to improve dissolution of a low melting point drug, ibuprofen (Ibu), using physical mixtures and coground formulations. The dissolution of the poorly soluble drug has been improved by changing the ratio of Ibu:GL and also grinding time. The results also showed that although GL can enhance the solubility of Ibu, it also reduces pH around the Ibu particles which led to poor dissolution performance when the concentration of GL is high. The effect of GL on the solubility of Ibu could be misleading if the pH of the final solution was not measured. Grinding reduced the particle size of GL significantly but in case of Ibu it was less effective. Solid state analysis (XRPD, DSC, and FT-IR) showed that ibuprofen is stable under grinding conditions, but the presence of high concentration of GL in samples subjected to high grinding times caused changes in FT-IR spectrum of Ibu which could be due to intermolecular hydrogen bond or esterification between the carboxylic acid group in the ibuprofen and hydroxyl group in the GL.


Assuntos
Liberação Controlada de Fármacos , Glucosamina/química , Ibuprofeno/química , Tecnologia Farmacêutica/métodos , Varredura Diferencial de Calorimetria , Relação Dose-Resposta a Droga , Concentração de Íons de Hidrogênio , Tamanho da Partícula , Solubilidade , Espectroscopia de Infravermelho com Transformada de Fourier , Fatores de Tempo , Difração de Raios X
13.
Pharm Dev Technol ; 19(3): 269-77, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-23506265

RESUMO

Psyllium has a mucilaginous property that makes it a good candidate to be utilized as an excipient in the preparation of controlled release systems. Various formulations were prepared using theophylline as a model drug and investigated with a view to achieve an ideal slow drug release profile. The addition of hydroxypropyl methylcellulose (HPMC) to psyllium significantly reduced the burst release; however, the percentage of drug release within a 12 h period was too slow and thereby inadequate. This was overcome by the addition of lactose as a hydrophilic filler that enabled a slow release with roughly 80% drug release in 12 h. The inclusion of HPMC within psyllium formulations changed the drug release kinetics from Fickian diffusion to anomalous transport. Granulated formulations demonstrated slower drug release than ungranulated or physical mixture and caused a change in the dissolution kinetics from Fickian diffusion to anomalous transport. Milled granules showed more efficient controlled drug release with no burst release. Milling of the granules also changed the drug release kinetics to anomalous transport. Although psyllium was proved to be a promising polymer to control the drug release, a combination of psyllium-HPMC and formulation processes should be considered in an attempt to achieve a zero-order release.


Assuntos
Broncodilatadores/administração & dosagem , Preparações de Ação Retardada/química , Metilcelulose/análogos & derivados , Psyllium/química , Teofilina/administração & dosagem , Derivados da Hipromelose , Metilcelulose/química , Solubilidade
14.
Am J Trop Med Hyg ; 110(6): 1127-1136, 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38697074

RESUMO

Animal African trypanosomiasis, also known as nagana, is caused by Trypanosoma species, which cause significant clinical diseases and lead to losses in animal production. We carried out a cross-sectional survey to investigate the composition of vectors and parasite diversity in two districts in the eastern region of Ghana where pigs and cattle were exposed to tsetse bites. We performed cytochrome c oxidase subunit 1 polymerase chain reaction (PCR) to identify tsetse species and internal transcribed spacer 1 PCR to identify Trypanosoma species. Also, we investigated the source of tsetse blood meal based on mitochondrial cytochrome b gene sequence analysis. A total of 229 tsetse, 65 pigs, and 20 cattle were investigated for trypanosomes. An overall vector density of 4.3 tsetse/trap/day was observed. A trypanosome prevalence of 58.9% (95% CI = 52.5-65.1%), 46.2% (95% CI = 34.6-58.1%), and 0.0% (95% CI = 0.0-16.1%) in tsetse, pigs, and cattle, respectively, was detected. Trypanosoma congolense was predominant, with a prevalence of 33.3% (95% CI = 73.3-86.5%) in tsetse. There was evidence of multiple infections in tsetse and pigs. Approximately 39% of the tsetse were positive for multiple infections of T. congolense and Trypanosoma simiae. Parasite prevalence in pigs across the communities was high, with significant differences associated between locations (χ2 = 28.06, 95% CI = 0.05-0.81, P = 0.0009). Tsetse blood meal analysis revealed feeding on domestic Sus scrofa domesticus (pigs) and Phacochoerus africanus (warthogs). Infective tsetse may transmit trypanosomes to livestock and humans in the communities studied.


Assuntos
Trypanosoma , Tripanossomíase Africana , Moscas Tsé-Tsé , Animais , Gana/epidemiologia , Moscas Tsé-Tsé/parasitologia , Bovinos , Tripanossomíase Africana/transmissão , Tripanossomíase Africana/epidemiologia , Tripanossomíase Africana/veterinária , Suínos , Trypanosoma/isolamento & purificação , Trypanosoma/genética , Trypanosoma/classificação , Estudos Transversais , Doenças dos Suínos/transmissão , Doenças dos Suínos/epidemiologia , Doenças dos Suínos/parasitologia , Insetos Vetores/parasitologia , Florestas , Doenças dos Bovinos/epidemiologia , Doenças dos Bovinos/transmissão , Doenças dos Bovinos/parasitologia , Prevalência , Feminino
15.
AAPS PharmSciTech ; 14(3): 1190-8, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23900884

RESUMO

Matrices containing PEO fail to provide stable drug release profiles when stored at elevated temperatures for a period of time. The present study aims to stabilize diltiazem HCl release from matrices made from various molecular weights of polyox powders. To this end, various molecular weights of polyox with and without vitamin E (0.25, 0.5 and 1% w/w) were stored at 40°C for 0, 2, 4 and 8 weeks. The aged polyox powders were then mixed with the model drug at a ratio of 1:1 and compressed into tablets. At different time intervals, the aged polyox with vitamin E were taken out of oven and mixed with the drug (1:1 ratio) and compressed into tablets. Dissolution studies showed a significant increase in diltiazem HCl release rate to occur with increased storage time at 40°C ± 1 from tablets made from the aged polyox (no vitamin E). This was as a result of depolymerization of the aged polyox powders as compared to the fresh polyox samples. This was confirmed by differential scanning calorimetry (DSC) which showed a reduction in the melting point of the aged samples. Concentrations of vitamin E as low as 0.25% w/w was able to overcome the quick release of drug from the matrices made from aged polyox powders. DSC traces showed that the melting point of aged polyox samples containing vitamin E remained the same as that of the fresh samples. The presence of vitamin E is essential to stabilize the drug release from polyox matrices containing diltiazem HCl.


Assuntos
Bloqueadores dos Canais de Cálcio/química , Diltiazem/química , Estabilidade de Medicamentos , Polietilenoglicóis/química , Pós , Varredura Diferencial de Calorimetria , Cinética , Solubilidade , Comprimidos , Vitamina E/química , Vitamina E/farmacocinética
16.
Biomedicines ; 11(6)2023 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-37371841

RESUMO

Upregulation of cyclooxygenase (COX-2) plays an important role in lung cancer pathogenesis. Celecoxib (CLX), a selective COX-2 inhibitor, may have beneficial effects in COVID-19-induced inflammatory storms. The current study aimed to develop carrier-free inhalable CLX microparticles by electrospraying as a dry powder formulation for inhalation (DPI). CLX microparticles were prepared through an electrospraying method using a suitable solvent mixture at two different drug concentrations. The obtained powders were characterized in terms of their morphology, solid state, dissolution behavior, and aerosolization performance. Electrosprayed particles obtained from the ethanol-acetone solvent mixture with a drug concentration of 3 % w/v exhibited the best in vitro aerosolization properties. The value of the fine particle fraction obtained for the engineered drug particles was 12-fold higher than that of the untreated CLX. When the concentration of CLX was increased, a remarkable reduction in FPF was obtained. The smallest median mass aerodynamic diameter was obtained from the electrosprayed CLX at a 3% concentration (2.82 µm) compared to 5% (3.25 µm) and untreated CLX (4.18 µm). DSC and FTIR experiments showed no change in drug crystallinity or structure of the prepared powders during the electrospraying process. The findings of this study suggest that electrospraying has potential applications in the preparation of DPI formulations.

17.
Pharmaceutics ; 15(8)2023 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-37631368

RESUMO

Hypromellose, a widely used polymer in the pharmaceutical industry, is available in several grades, depending on the percentage of substitution of the methoxyl and hydroxypropyl groups and molecular weight, and in various functional forms (e.g., suitable for direct compression tableting). These differences can affect their physicomechanical properties, and so this study aims to characterise the particle size and mechanical properties of HPMC K100M polymer grades from four different vendors. Eight polymers (CR and DC grades) were analysed using scanning electron microscopy (SEM) and light microscopy automated image analysis particle characterisation to examine the powder's particle morphology and particle size distribution. Bulk density, tapped density, and true density of the materials were also analysed. Flow was determined using a shear cell tester. Flat-faced polymer compacts were made at five different compression forces and the mechanical properties of the compacts were evaluated to give an indication of the powder's capacity to form a tablet with desirable strength under specific pressures. The results indicated that the CR grades of the polymers displayed a smaller particle size and better mechanical properties compared to the DC grade HPMC K100M polymers. The DC grades, however, had better flow properties than their CR counterparts. The results also suggested some similarities and differences between some of the polymers from the different vendors despite the similarity in substitution level, reminding the user that care and consideration should be given when substitution is required.

18.
Int J Pharm ; 631: 122507, 2023 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-36535457

RESUMO

In this study, the Supercritical Carbon Dioxide (scCO2) gas foaming procedure was used in the preparation of scaffolds containing the model drug dexamethasone (DXMT). The method used did not include an organic solvent thus making it a safe method. The ring-opening polymerization of PCL-PEG-PCL (PCEC) triblock was conducted using an organocatalyst [1,8 diazabicyclo [5.4.0] undec-7-ene (DBU)]. After mixing 5.0 g of DXMT with 50.0 g of PCEC, hydraulic pressure was applied to compress the mixed powder into disc-like tablets. The tablet-like scaffold of the triblock containing DXMT was inserted into a scCO2 gas-foaming device. The peak porosity percentage of the synthesized triblock was found to be 55.58 %. Pressure, temperature, soaking time and the time required to depressurize were recorded as 198 bar, 50 °C, 2.0 h, and 28 min respectively. After treatment with scCO2, the scaffolds experienced an almost full release of DXMT in vitro after 30 days (83.74 ± 1.54 % vs 52.24 ± 2.03 % before scCO2 treatment). In conclusion, the results proved that the scCO2 gas foaming procedure could be employed for constructing modifiable PCEC scaffolds with plausible porosity and structural and morphological features which can manipulate drug release.


Assuntos
Dióxido de Carbono , Alicerces Teciduais , Alicerces Teciduais/química , Dióxido de Carbono/química , Porosidade , Polietilenoglicóis/química , Poliésteres/química , Engenharia Tecidual/métodos
19.
Drug Discov Today ; 27(2): 471-489, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34781032

RESUMO

The uncontrolled release of drugs in conventional drug delivery systems has led to the introduction of new nanotechnology-based drug delivery systems and the use of targeted nanocarriers for cancer treatment. These targeted nanocarriers, which consist of intelligent nanoparticles modified with targeting ligands, can deliver drugs to specified locations at the right time and reduce drug doses to prevent side effects. Folate is a suitable targeting ligand for folate receptors overexpressed on cancer cells and has shown promising results in the diagnosis and treatment of cancer. In this review, we highlight the latest developments on the use of folate-conjugated nanoparticles in cancer diagnosis and treatment. Moreover, the toxicity, biocompatibility and efficacy of these nanocarriers are discussed.


Assuntos
Nanopartículas , Neoplasias , Portadores de Fármacos/uso terapêutico , Sistemas de Liberação de Medicamentos/métodos , Ácido Fólico/uso terapêutico , Humanos , Ligantes , Neoplasias/tratamento farmacológico
20.
Pharmaceutics ; 14(5)2022 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-35631481

RESUMO

It has been hypothesized that simvastatin could be used to treat pulmonary arterial hypertension (PAH). This study is intended to formulate a simvastatin nanoparticle dry powder inhalation (DPI) formulation. Simvastatin nanoparticles were prepared via an emulsification and homogenization-extrusion method, followed by spray drying of the colloidal suspension of simvastatin nanoparticles containing mannitol to get it into a respirable size. Particle size distribution, morphology, and crystallinity of the fabricated nanoparticles of the obtained microparticles for DPI formulation were assessed by dynamic light scattering (DLS), scanning electron microscopy (SEM), and X-ray diffraction pattern (XRPD), respectively. Aerosolization performance of the DPI formulation was assessed by the Next Generation Impactor (NGI) equipped with an Aerolizer®. Simvastatin nanoparticles were around 100 nm with a very narrow size distribution (PDI = 0.105). The X-ray diffraction pattern revealed that the crystallinity of simvastatin was decreased by the spray drying procedure. Microscopic images displayed that gathered nanoparticles were in the suitable inhalable range and had the appropriate shape and surface properties for pulmonary delivery. Aerosolization assessment by the NGI indicated a suitable inhalation performance (fine particle fraction of 20%). In conclusion, the results confirmed that the spray drying technique for simvastatin can be optimized to obtain simvastatin aggregated nanoparticles without any coarse carrier to be used in DPI formulation for better deposition of the drug in the lungs for local treatment of PAH.

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