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2.
Pharmacy (Basel) ; 9(4)2021 Sep 23.
Artículo en Inglés | MEDLINE | ID: mdl-34698217

RESUMEN

Whilst curriculum revision is commonplace, whole degree transformation is less so. In this paper we discuss the rationale, design and implementation of a unique pharmacy program by a research-intensive faculty. The new Monash pharmacy curriculum, which had its first intake in 2017, was built using a range of key innovations that aimed to produce graduates that demonstrate key conceptual understanding and all the skills required to deliver world-best patient outcomes. The key elements of the re-design are outlined and include the process and principles developed, as well as key features such as a student-centred individualised program of development arranged around specific, authentic tasks for each skill and earlier enhanced experiential placements where students become proficient in entrustable professional activities. It is hoped the dissemination of this process, as well as the lessons learnt in the process, will be useful to others looking to transform a health curriculum.

3.
Pharmaceutics ; 13(8)2021 Aug 13.
Artículo en Inglés | MEDLINE | ID: mdl-34452215

RESUMEN

Roflumilast is currently administered orally to control acute exacerbations in chronic obstructive pulmonary disease (COPD). However, side effects such as gastrointestinal disturbance and weight loss have limited its application. This work aimed to develop an inhalable roflumilast formulation to reduce the dose and potentially circumvent the associated toxicity. Roflumilast was cospray-dried with trehalose and L-leucine with varied feed concentrations and spray-gas flow rates to produce the desired dry powder. A Next-Generation Impactor (NGI) was used to assess the aerosolization efficiency. In addition, different devices (Aerolizer, Rotahaler, and Handihaler) and flow rates were used to investigate their effects on the aerosolization efficiency. A cytotoxicity assay was also performed. The powders produced under optimized conditions were partially amorphous and had low moisture content. The powders showed good dispersibility, as evident by the high emitted dose (>88%) and fine particle fraction (>52%). At all flow rates (≥30 L/min), the Aerolizer offered the best aerosolization. The formulation exhibited stable aerosolization after storage at 25 °C/15% Relative Humidity (RH) for one month. Moreover, the formulation was non-toxic to alveolar basal epithelial cells. A potential inhalable roflumilast formulation including L-leucine and trehalose has been developed for the treatment of COPD. This study also suggests that the choice of device is crucial to achieve the desired aerosol performance.

5.
J Alzheimers Dis ; 62(2): 867-876, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29480198

RESUMEN

BACKGROUND: Clinical practice guidelines for dementia highlight the importance of providing patient-centered care. This can be achieved by improving health professionals' attitudes and knowledge toward people with dementia. OBJECTIVE: Quantitatively evaluate the impact of a virtual dementia experience on medical and pharmacy students' knowledge and attitudes toward people with dementia. METHODS: A non-randomized controlled study from September-October 2016. The intervention group received a 1.5-hour multisensory, virtual simulation of light, sound, color, and visual content to experience the cognitive and perceptual difficulties faced by people with dementia. Controls participated in the standard curriculum only. All students were invited to complete the 20-item Dementia Attitudes Scale (DAS) pre- and post-intervention. RESULTS: A total of 278 students (n = 64 medical, n = 214 pharmacy) were analyzed (n = 80 intervention, n = 198 control). The majority of students were female (n = 184, 66.2%), with an average age of 22.5 years. The intervention improved the DAS total score and subdomains of comfort and knowledge (p < 0.001). CONCLUSION: The intervention had a positive impact on medical and pharmacy students' knowledge and attitudes toward people with dementia.


Asunto(s)
Demencia/psicología , Conocimientos, Actitudes y Práctica en Salud , Estudiantes de Medicina , Estudiantes de Farmacia , Realidad Virtual , Australia , Curriculum/normas , Femenino , Humanos , Masculino , Adulto Joven
6.
Innov Pharm ; 9(3): 1-9, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-34007707

RESUMEN

In November 2016, the International Pharmaceutical Federation (FIP) endeavored to create an environment to foster a shared vision to lead a transformative pharmaceutical workforce roadmap. Three milestone documents were developed and presented at the Global Conference on Pharmacy and Pharmaceutical Education. Workshops with the key themes and connecting Pharmaceutical Workforce Development Goals (PWDG) were conducted and analyzed. This Note serves to summarize the key aspects of these workshops, reporting on the innovative approaches used to generate guidance for stakeholders regarding implementation. INNOVATION: Seven workshops with a uniform structure were developed. These were designed to improve communication, harmonise outcome-generation, and allow for aggregate analysis. A team of seven conducted each workshop, each team consisted of: a Chair, a facilitator, one rapporteur, and four speakers purposively selected from FIP member organisations and other key stakeholders with expertise for sharing a variety of perspectives. Guidelines and templates were developed for all roles and each team was briefed in advance. KEY FINDINGS: Approximately 200 personnel participated in the seven workshops, with around 20 country representatives per workshop, covering all six World Health Organisation regions. Three key aspects of workforce transformation, using the PWDGs, were explored in each workshop: drivers for implementation; challenges to implementation; and ways of encouraging implementation. Drivers for implementation mentioned were enhancing collaboration and engagement. Challenges to implementation were identified as variance in terminology. Several ways of encouraging implementation were acknowledged, such as communication strategies, advocating for workforce development and sharing best practices to foster partnerships. NEXT STEPS: The unique format of the workshops, the innovative approach to include stakeholders across an array of settings and the parallel structure in all the seven workshops, aided in creating reliable findings. The achievability of the PWDGs depends on several factors. Engagement with stakeholders and engagement from and between professional associations are important factors to achieving workforce development goals.

7.
J Pharm Biomed Anal ; 145: 711-717, 2017 Oct 25.
Artículo en Inglés | MEDLINE | ID: mdl-28806567

RESUMEN

Liquid intrusion remains one of the most common methods to measure the contact angle of liquids to powders. However, as there are two unknown variables in the Washburn equation: the material constant (that is, the pore structure of the powder bed) and the contact angle of the liquid to the powder, this method requires the use of two liquids-a liquid of interest (the probe liquid) and a reference liquid. The reference liquid should, ideally, make a contact angle of 0° to the sample. However, in practice a low surface tension liquid is normally selected. This paper proposes a more standardised approach for the selection of the reference liquid based on experimental data. Additionally, a major assumption of the liquid intrusion method is that the pore structure, as measured by the material constant, C, is identical for all powder beds (provided that the same packing procedure is used for the same samples). In real systems, however, this is an approximation, and not likely to hold strictly true. Therefore, difficulties may arise with data analysis as there is a potential uncertainty in the most appropriate order to divide the gradient of the probe liquid by the gradient of the reference liquid. This paper proposes three specific methods of analysing such data, each with their own advantages and limitations. Hence, the selection of which method should be used is criteria-based, assessed on the basis of the obtained data.


Asunto(s)
Porosidad , Polvos , Tensión Superficial
8.
Am J Pharm Educ ; 81(9): 5931, 2017 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-29302082

RESUMEN

Objective: To investigate the relationship between student engagement with the key elements of a flipped classroom approach (preparation and attendance), their attitudes to learning, including strategy development, and their performance on two types of examination questions (knowledge recall and providing rational predictions when faced with novel scenarios). Methods. This study correlated student engagement with the flipped classroom and student disposition to learning with student ability to solve novel scenarios in examinations. Results. Students who both prepared for and attended classes performed significantly better on examination questions that required analysis of novel scenarios compared to students who did not prepare and missed classes. However, there was no difference for both groups of students on examination questions that required knowledge and comprehension. Student motivation and use of strategies correlated with higher examination scores on questions requiring novel scenario analysis. Conclusion. There is a synergistic relationship between class preparation and attendance. The combination of preparation and attendance was positively correlated to assessment type; the relationship was apparent for questions requiring students to solve novel problems but not for questions requiring knowledge or comprehension.


Asunto(s)
Educación en Farmacia/métodos , Evaluación Educacional/métodos , Aprendizaje Basado en Problemas/métodos , Estudiantes de Farmacia/psicología , Encuestas y Cuestionarios , Enseñanza , Rendimiento Académico , Curriculum , Escolaridad , Humanos , Recuerdo Mental , Habilidades para Tomar Exámenes
9.
J Pharm Sci ; 105(7): 2173-9, 2016 07.
Artículo en Inglés | MEDLINE | ID: mdl-27312508

RESUMEN

The peptide HsTX1[R14A] is a potent and selective blocker of the voltage-gated potassium channel Kv1.3, a well-recognized therapeutic target for autoimmune diseases. To overcome the poor oral absorption and consequent need for regular injections, the potential of the buccal mucosa for systemic delivery of HsTX1[R14A] was investigated. For in vitro studies, FITC-HsTX1[R14A] and HsTX1[R14A], in solution or formulated in a mucoadhesive chitosan-based gel (3%, w/v) with or without cetrimide (5%, w/w), were applied to porcine buccal epithelium mounted between Ussing chambers and buccal mucosal permeation assessed. HsTX1[R14A] was also administered to Swiss outbred mice at a dose of 10 mg/kg in the same formulations. In vitro, administration of FITC-HsTX1[R14A] and HsTX1[R14A] in the chitosan gel containing cetrimide resulted in detectable buccal permeation with 0.75% and 0.58%, respectively, of the applied dose appearing in the receptor chamber over 5 h. After buccal administration to mice, HsTX1[R14A] was detected in plasma, with the presence of cetrimide in the gel further enhancing plasma exposure, with area under the plasma concentration-time curve values of 77.9 ± 9.7 and 31.0 ± 2.3 nM·h, respectively. The buccal mucosa is a promising alternative administration route for the systemic delivery of HsTX1[R14A] for the treatment of autoimmune diseases.


Asunto(s)
Canal de Potasio Kv1.3/antagonistas & inhibidores , Mucosa Bucal/metabolismo , Bloqueadores de los Canales de Potasio/administración & dosificación , Venenos de Escorpión/administración & dosificación , Administración Bucal , Animales , Cetrimonio , Compuestos de Cetrimonio , Quitosano , Composición de Medicamentos , Sistemas de Liberación de Medicamentos , Excipientes , Ratones , Permeabilidad , Soluciones Farmacéuticas , Porcinos , Adhesivos Tisulares
10.
Eur J Pharm Biopharm ; 104: 110-6, 2016 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-27132984

RESUMEN

OBJECTIVE: In this study, we investigated the applicability of cohesive-adhesive balance (CAB) model to predict the interactive mixing behaviour of small excipient particles. Further, we also investigated the application of this CAB model to predict the flow and compactibility of resultant blends. METHODS: Excipients created by co-spraying polyvinylpyrrolidone (PVP, a model pharmaceutical binder) with various l-leucine concentrations were used for this study. Paracetamol was used as model active pharmaceutical ingredient (API). The surface energy was used to derive the work of cohesion (wco) and work of adhesion (wad) to predict the interactive mixing behaviour of the excipients with paracetamol. The blends were visualised under a scanning electron microscopy microscope to assess the interactive mixing behaviour. In addition, the flow performance and tabletting behaviour of various blends were characterised. RESULTS: The surface-energy derived work of adhesion (wad) between excipient and paracetamol particles increased, while the corresponding work of cohesion (wco) between excipient particles decreased, with increasing l-leucine concentrations. In blends for which the work of cohesion was higher than the work of adhesion (wco>wad), small excipient particles were apparent as agglomerates. For excipients with 5% and higher l-leucine concentrations, the work of adhesion between excipient and paracetamol particles was higher than or equivalent to the work of cohesion between excipient particles (wad⩾wco) and agglomerates were less apparent. This is an indicator of formation of homogeneous interactive mixtures. At 5% (w/w) excipient proportions, blends for which wad⩾wco demonstrated higher compactibility than other blends. Furthermore, at 10% (w/w) and higher excipient proportions, these blends also demonstrated better flow performance than other blends. CONCLUSION: In conclusion, this is the first study to demonstrate that surface-energy derived CAB data effectively predict the interactive mixing behaviour of small excipient particles. Furthermore, at certain proportions of small excipient particles the CAB model also predicts the flow and compaction behaviour of the API/excipient blends.


Asunto(s)
Modelos Teóricos , Química Farmacéutica , Microscopía Electrónica de Rastreo , Propiedades de Superficie
11.
Int J Pharm ; 514(2): 341-352, 2016 Dec 05.
Artículo en Inglés | MEDLINE | ID: mdl-27032565

RESUMEN

In this study, we investigated the influence of deformability of specifically-engineered guest particles on the tensile strength of tablets of interactive mixtures. The binder polyvinylpyrrolidone (PVP) of different molecular weights were spray dried with l-leucine to create guest particle formulations. The guest particle formulations were characterized by their particle size, surface l-leucine concentration and glass transition temperature (Tg). These spray-dried particles were then blended with paracetamol to form interactive mixtures, which were compacted into tablets and tablet tensile strength and elastic recovery were determined. The guest particles had particle diameters in the range of 1-10µm, and surfaces that were l-leucine enriched. The Tg of guest particle formulations increased with increasing molecular weight of the PVP. All the guest particle formulations formed an observed homogeneous interactive mixture with paracetamol. The tensile strength of the tablets of interactive mixtures increased with decreasing Tg of the guest particles. In these interactive mixtures, higher tensile strength was also associated with lower tablet elastic recovery. The elastic recovery of the tablets showed a correlation with the elastic recovery of the tablets of guest particles. Thus, our results indicated that the deformability of guest particles dictates the tensile strength of the tablets of these interactive mixtures.


Asunto(s)
Química Farmacéutica/métodos , Composición de Medicamentos/métodos , Elasticidad , Resistencia a la Tracción , Acetaminofén/química , Leucina/química , Tamaño de la Partícula , Povidona/química , Comprimidos/química , Temperatura de Transición
12.
Eur J Pharm Biopharm ; 102: 168-77, 2016 May.
Artículo en Inglés | MEDLINE | ID: mdl-26972416

RESUMEN

In this study, we aimed to investigate the effects cohesion of small surface-engineered guest binder particles on the flow behaviour of interactive mixtures. Polyvinylpyrrolidone (PVP) - a model pharmaceutical binder - was spray-dried with varying l-leucine feed concentrations to create small surface-engineered binder particles with varying cohesion. These spray-dried formulations were characterised by their particle size distribution, morphology and cohesion. Interactive mixtures were produced by blending these spray-dried formulations with paracetamol. The resultant blends were visualised under scanning electron microscope to confirm formation of interactive mixtures. Surface coverage of paracetamol by guest particles as well as the flow behaviour of these mixtures were examined. The flow performance of interactive mixtures was evaluated using measurements of conditioned bulk density, basic flowability energy, aeration energy and compressibility. With higher feed l-leucine concentrations, the surface roughness of small binder particles increased, while their cohesion decreased. Visual inspection of the SEM images of the blends indicated that the guest particles adhered to the surface of paracetamol resulting in effective formation of interactive mixtures. These images also showed that the low-cohesion guest particles were better de-agglomerated that consequently formed a more homogeneous interactive mixture with paracetamol compared with high-cohesion formulations. The flow performance of interactive mixtures changed as a function of the cohesion of the guest particles. Interactive mixtures with low-cohesion guest binder particles showed notably improved bulk flow performance compared with those containing high-cohesion guest binder particles. Thus, our study suggests that the cohesion of guest particles dictates the flow performance of interactive mixtures.


Asunto(s)
Química Farmacéutica/métodos , Tecnología Farmacéutica/métodos , Acetaminofén/química , Excipientes/química , Leucina/química , Tamaño de la Partícula , Povidona/química , Propiedades de Superficie
13.
J Pharm Sci ; 105(2): 650-656, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26869426

RESUMEN

HsTX1[R14A] is a potent and selective Kv1.3 channel blocker peptide with the potential to treat autoimmune diseases. Given the typically poor oral bioavailability of peptides, we evaluated pulmonary administration of HsTX1[R14A] in rats as an alternative route for systemic delivery. Plasma concentrations of HsTX1[R14A] were measured by liquid chromatography coupled with tandem mass spectrometry in rats receiving intratracheal administration of HsTX1[R14A] in solution (1-4 mg/kg) or a mannitol-based powder (1 mg/kg) and compared with plasma concentrations after intravenous administration (2 mg/kg). HsTX1[R14A] stability in rat plasma and lung tissue was also determined. HsTX1[R14A] was more stable in plasma than in lung homogenate, with more than 90% of the HsTX1[R14A] remaining intact after 5 h, compared with 40.5% remaining in lung homogenate. The terminal elimination half-life, total clearance, and volume of distribution of HsTX1[R14A] after intravenous administration were 79.6 ± 6.5 min, 8.3 ± 0.6 mL/min/kg, and 949.8 ± 71.0 mL/kg, respectively (mean ± SD). After intratracheal administration, HsTX1[R14A] in solution and dry powder was absorbed to a similar degree, with absolute bioavailability values of 39.2 ± 5.2% and 44.5 ± 12.5%, respectively. This study demonstrated that pulmonary administration is a promising alternative for systemically delivering HsTX1[R14A] for treating autoimmune diseases.


Asunto(s)
Enfermedades Autoinmunes/metabolismo , Sistemas de Liberación de Medicamentos/métodos , Canal de Potasio Kv1.3/antagonistas & inhibidores , Pulmón/metabolismo , Bloqueadores de los Canales de Potasio/metabolismo , Venenos de Escorpión/metabolismo , Animales , Enfermedades Autoinmunes/tratamiento farmacológico , Línea Celular , Supervivencia Celular/efectos de los fármacos , Supervivencia Celular/fisiología , Células Cultivadas , Relación Dosis-Respuesta a Droga , Pulmón/efectos de los fármacos , Masculino , Bloqueadores de los Canales de Potasio/administración & dosificación , Ratas , Ratas Sprague-Dawley , Venenos de Escorpión/administración & dosificación , Resultado del Tratamiento
14.
J Pharm Sci ; 105(3): 1156-63, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26886330

RESUMEN

This study aimed to investigate the surface energy factors behind improved aerosolization performance of spray-dried colistin powder formulations compared with those produced by jet milling. Inhalable colistin powder formulations were produced by jet milling or spray drying (with or without l-leucine). Scanning electron micrographs showed the jet-milled particles had irregularly angular shapes, whereas the spray-dried particles were more spherical. Significantly higher fine particle fractions were measured for the spray-dried (43.8%-49.6%) versus the jet-milled formulation (28.4%) from a Rotahaler at 60 L/min; albeit the size distribution of the jet-milled powder was smaller. Surprisingly, addition of l-leucine in the spray drying feed solution gave no significant improvement in fine particle fraction. As measured by inverse gas chromatography, spray-dried formulations had significantly (p < 0.001) lower dispersive, specific, and total surface energy values and more uniform surface energy distributions than the jet-milled powder. Interestingly, no significant difference was measured in the specific and total surface energy values between the spray-dried formulation with or without l-leucine. Based on our previous findings in the self-assembling behavior of colistin in aqueous solution and the surface energy data obtained here, we propose the self-assembly of colistin molecules during spray drying contributed significantly to the reduction of surface free energy and the superior aerosolization performance.


Asunto(s)
Aerosoles/química , Colistina/química , Polvos/química , Administración por Inhalación , Química Farmacéutica/métodos , Inhaladores de Polvo Seco/métodos , Leucina/química , Microscopía Electrónica de Rastreo/métodos , Tamaño de la Partícula , Soluciones/química
15.
Am J Pharm Educ ; 80(9): 158, 2016 Nov 25.
Artículo en Inglés | MEDLINE | ID: mdl-28090107

RESUMEN

Objective. To use the nominal group technique to develop a framework to improve existing and develop new objective structured clinical examinations (OSCEs) within a four-year bachelor of pharmacy course. Design. Using the nominal group technique, a unique method of group interview that combines qualitative and quantitative data collection, focus groups were conducted with faculty members, practicing pharmacists, and undergraduate pharmacy students. Five draft OSCEs frameworks were suggested and participants were asked to generate new framework ideas. Assessment. Two focus groups (n=9 and n=7) generated nine extra frameworks. Two of these frameworks, one from each focus group, ranked highest (mean scores of 4.4 and 4.1 on a 5-point scale) and were similar in nature. The project team used these two frameworks to produce the final framework, which includes an OSCE in every year of the course, earlier implementation of teaching OSCEs, and the use of independent simulated patients who are not examiners. Conclusions. The new OSCE framework provides a consistent structure from course entry to exit and ensures graduates meet internship requirements.


Asunto(s)
Educación en Farmacia/métodos , Evaluación Educacional/métodos , Acreditación , Australia , Educación en Farmacia/normas , Docentes de Farmacia , Objetivos , Farmacéuticos , Competencia Profesional , Estudiantes de Farmacia
16.
Curr Pharm Des ; 21(40): 5751-65, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26446467

RESUMEN

The flow of powders can often play a critical role in the manufacturing of pharmaceutical products. Many of these processes require good, consistent and predictable flow of powders to ensure continuous production of pharmaceutical dosages and to ensure their quality. Therefore, the flow of powders is of paramount importance to the pharmaceutical industry and thus the measuring and evaluating of powder flow is of utmost importance. At present, there are numerous methods in which the flow of powders can be measured. However, due to the complex and environment-dependent nature of powders, no one method exists that is capable of providing a complete picture of the behaviour of powders under dynamic conditions. Some of the most commonly applied methods to measure the flow of powders include: density indices, such as the Carr index and Hausner ratio, powder avalanching, the angle of repose (AOR), flow through an orifice, powder rheometry and shear cell testing.


Asunto(s)
Composición de Medicamentos/normas , Excipientes/química , Polvos/química , Tecnología Farmacéutica/métodos , Algoritmos , Química Farmacéutica , Composición de Medicamentos/estadística & datos numéricos , Humanos , Tamaño de la Partícula , Propiedades de Superficie
17.
Curr Pharm Des ; 21(40): 5877-89, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26446468

RESUMEN

Tablets represent the preferred and most commonly dispensed pharmaceutical dosage form for administering active pharmaceutical ingredients (APIs). Minimizing the cost of goods and improving manufacturing output efficiency has motivated companies to use direct compression as a preferred method of tablet manufacturing. Excipients dictate the success of direct compression, notably by optimizing powder formulation compactability and flow, thus there has been a surge in creating excipients specifically designed to meet these needs for direct compression. Greater scientific understanding of tablet manufacturing coupled with effective application of the principles of material science and particle engineering has resulted in a number of improved direct compression excipients. Despite this, significant practical disadvantages of direct compression remain relative to granulation, and this is partly due to the limitations of direct compression excipients. For instance, in formulating high-dose APIs, a much higher level of excipient is required relative to wet or dry granulation and so tablets are much bigger. Creating excipients to enable direct compression of high-dose APIs requires the knowledge of the relationship between fundamental material properties and excipient functionalities. In this paper, we review the current understanding of the relationship between fundamental material properties and excipient functionality for direct compression.


Asunto(s)
Química Farmacéutica , Excipientes/química , Preparaciones Farmacéuticas/química , Polvos/química , Comprimidos/química , Tecnología Farmacéutica/métodos , Humanos , Tamaño de la Partícula
18.
Eur J Pharm Biopharm ; 94: 160-9, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-26007290

RESUMEN

The amino acid L-leucine has been demonstrated to act as a lubricant and improve the dispersibility of otherwise cohesive fine particles. It was hypothesized that optimum surface L-leucine concentration is necessary to achieve optimal surface and bulk powder properties. Polyvinylpyrrolidone was spray dried with different concentration of L-leucine and the change in surface composition of the formulations was determined using X-ray photoelectron spectroscopy (XPS) and time of flight-secondary ion mass spectrometry (ToF-SIMS). The formulations were also subjected to powder X-ray diffraction analysis in order to understand the relationship between surface concentration and solid-state properties of L-leucine. In addition, the morphology, surface energy and bulk cohesion of spray dried formulations were also assessed to understand the relation between surface L-leucine concentration and surface and bulk properties. The surface concentration of L-leucine increased with higher feed concentrations and plateaued at about 10% L-leucine. Higher surface L-leucine concentration also resulted in the formation of larger L-leucine crystals and not much change in crystal size was noted above 10% L-leucine. A change in surface morphology of particles from spherical to increasingly corrugated was also observed with increasing surface l-leucine concentration. Specific collapsed/folded over particles were only seen in formulations with 10% or higher l-leucine feed concentration suggesting a change in particle surface formation process. In addition, bulk cohesion also reduced and approached a minimum with 10% L-leucine concentration. Thus, the surface concentration of L-leucine governs particle formation and optimum surface L-leucine concentration results in optimum surface and bulk powder properties.


Asunto(s)
Desecación , Leucina/química , Lubricantes/química , Tecnología Farmacéutica/métodos , Aerosoles , Química Farmacéutica , Cromatografía de Gases , Cristalización , Cristalografía por Rayos X , Espectrometría de Masas , Microscopía Electrónica de Rastreo , Espectroscopía de Fotoelectrones , Povidona/química , Difracción de Polvo , Polvos , Propiedades de Superficie
19.
Int J Pharm ; 479(2): 338-48, 2015 Feb 20.
Artículo en Inglés | MEDLINE | ID: mdl-25572691

RESUMEN

In this study, polyvinylpyrrolidone (PVP) was spray dried with l-leucine (PVP-Leu) to create a prototype multifunctional interactive excipient. The physico-chemical and bulk properties such as particle size, surface composition, surface energy and bulk cohesion of PVP-Leu was measured and compared against pure spray dried PVP (PVP-SD). The mixing behaviour of these excipients and their effect on flow and binder activity of paracetamol was assessed. The mean particle sizes of PVP-Leu PVP-SD and PVP were 2.5, 2.1 and 21.9µm, respectively. Surface composition characterization indicated that l-leucine achieved higher concentrations on the surface compared to the bulk of the PVP-Leu particles. The surface energy of PVP-Leu was significantly lower compared to PVP-SD. In addition, PVP-Leu exhibited a significantly lower bulk cohesion compared PVP-SD. The excipients were blended with paracetamol and qualitative characterization indicated that PVP-Leu blended more homogeneously with paracetamol compared to PVP-SD. Both PVP-Leu and PVP-SD then exhibited a significantly improved binder activity compared to PVP. The flow of the paracetamol was markedly improved with PVP-Leu while PVP-SD and PVP had negligible effect on its flow. This study reveals how physico-chemical and bulk properties of such prototype interactive excipients can play a key role in determining multi-factorial excipient performance.


Asunto(s)
Acetaminofén/administración & dosificación , Excipientes/química , Leucina/química , Povidona/química , Acetaminofén/química , Química Farmacéutica , Composición de Medicamentos , Tamaño de la Partícula
20.
Int J Pharm ; 477(1-2): 351-60, 2014 Dec 30.
Artículo en Inglés | MEDLINE | ID: mdl-25196720

RESUMEN

This study aims to improve understanding of the powder fluidisation and aerosolisation processes unique to a split capsule dry powder inhaler. It uses a combination of dynamic real-time methods and a suite of powder material physicochemical characterisation methods. The study focused on examining the effect of different characteristics of lactose carrier employed, and considered specifically the powder fluidisation, entrainment and de-agglomeration mechanisms. A GSK Rotahaler(®) was selected as the inhaler device. Powder fluidisation and entrainment were investigated using the ensemble technique of laser diffraction and high-speed imaging. This ensemble technique afforded both the powder entrainment profile and simultaneous visual confirmation of the capsule movement and powder fluidisation within the Rotahaler. The results showed that powder fluidisation from a dynamic split capsule was substantially different to that from a static powder bed. Furthermore, the presence of the split capsule dominated powder emission mechanisms from the Rotahaler, regulated by its impaction on the grid/Rotahaler wall and the rotational movement in the entrained air. Of all the material characterisation metrics, the most significant linear correlation was revealed between powder permeability and the aerosolisation efficiency as measured by fine particle fraction (R(2)=0.98). This indicates that drug delivery from the Rotahaler was mainly governed by the influence of the cohesive fine particle size component. Powder permeability as a practical test may afford an effective and practical predictive link between the raw excipients and drug delivery performance from the capsule device.


Asunto(s)
Albuterol/administración & dosificación , Broncodilatadores/administración & dosificación , Sistemas de Liberación de Medicamentos/instrumentación , Sistemas de Liberación de Medicamentos/métodos , Inhaladores de Polvo Seco/normas , Aerosoles , Portadores de Fármacos/química , Lactosa/química , Microscopía Electrónica de Rastreo , Modelos Teóricos , Tamaño de la Partícula , Polvos , Propiedades de Superficie
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