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1.
Gerodontology ; 2024 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-38544301

RESUMO

OBJECTIVES: SENIOR (uSing rolE-substitutioN In care homes to improve oRal health) is a randomised controlled trial designed to determine whether role substitution could improve oral health for this population. A parallel process evaluation was undertaken to understand context. This paper reports on the first phase of the process evaluation. BACKGROUND: The oral health and quality-of-life of older adults residing in care homes is poorer than those in the community. Oral health care provision is often unavailable and a concern and challenge for managers. The use of Dental Therapists and Dental Nurses rather than dentists could potentially meet these needs. MATERIALS AND METHODS: Semi-structured interviews were conducted with 21 key stakeholders who either worked or had experience of dependent care settings. Questions were theoretically informed by the: Promoting Action on Research Implementation in Health Services (PAHRIS) framework. The focus was on contextual factors that could influence adoption in practice and the pathway-to-impact. Interviews were fully transcribed and analysed thematically. RESULTS: Three themes (receptive context, culture, and leadership) and 11 codes were generated. Data show the complexity of the setting and contextual factors that may work as barriers and facilitators to intervention delivery. Managers are aware of the issues regarding oral health and seek to provide best care, but face many challenges including staff turnover, time pressures, competing needs, access to services, and financial constraints. Dental professionals recognise the need for improvement and view role substitution as a viable alternative to current practice. CONCLUSION: Although role substitution could potentially meet the needs of this population, an in-depth understanding of contextual factors appeared important in understanding intervention delivery and implementation.

2.
BMC Health Serv Res ; 17(1): 175, 2017 03 06.
Artigo em Inglês | MEDLINE | ID: mdl-28264677

RESUMO

BACKGROUND: In May 2009, the Northern Ireland government introduced General Dental Services (GDS) contracts based on capitation in dental practices newly set up by a corporate dental provider to promote access to dental care in populations that had previously struggled to secure service provision. Dental service provision forms an important component of general health services for the population, but the implications of health system financing on care delivered and the financial cost of services has received relatively little attention in the research literature. The aim of this study is to evaluate the policy effect capitation payment in recently started corporate practices had on the delivery of primary oral healthcare in Northern Ireland and access to services. METHODS: We analysed the policy initiative in Northern Ireland as a natural experiment to find the impact on healthcare delivery of the newly set up corporate practices that use a prospective capitation system to remunerate primary care dentists. Data was collected from GDS claim forms submitted to the Business Services Organisation (BSO) between April 2011 and October 2014. Health and Social Care Board (HSCB) practices operating within a capitation system were matched to a control group, who were remunerated using a retrospective fee-for-service system. RESULTS: No evidence of patient selection was found in the HSCB practices set up by a corporate provider and operated under capitation. However, patients were less likely to visit the dentist and received less treatment when they did attend, compared to those belonging to the control group (P < 0.05). The extent of preventive activity offered and the patient payment charge revenue did not differ between the two practice groups. CONCLUSION: Although remunerating NHS primary care dentists in newly set up corporate practices using a prospective capitation system managed costs within healthcare, there is evidence that this policy may have reduced access to care of registered patients.


Assuntos
Capitação , Atenção à Saúde/estatística & dados numéricos , Assistência Odontológica/economia , Atenção à Saúde/economia , Assistência Odontológica/estatística & dados numéricos , Odontólogos/economia , Planos de Pagamento por Serviço Prestado , Honorários e Preços , Feminino , Gastos em Saúde , Acessibilidade aos Serviços de Saúde/economia , Acessibilidade aos Serviços de Saúde/estatística & dados numéricos , Humanos , Masculino , Irlanda do Norte , Projetos Piloto , Atenção Primária à Saúde , Estudos Prospectivos , Remuneração , Estudos Retrospectivos
3.
BDJ Open ; 9(1): 14, 2023 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-37037830

RESUMO

INTRODUCTION: A small number of literature has posited a link between prenatal exposure to gestational diabetes mellitus and an increased risk of developmental defects in the enamel of offspring. However, the evidence remains inconclusive. AIMS: This study examined the relationship between the diabetes status of mothers and the use of dental services by offspring to that pregnancy. MATERIAL AND METHODS: Anonymised data from a cohort of mothers who carried a child to term in Northern Ireland between 2012 and 2017 and service use by the child were taken from administrative databases from March 2015 to September 2021. Descriptive statistics, differences in means and regression analyses were used to examine the relationship between service use and maternal diabetes status, controlling for covariates. RESULTS: In multivariate analyses that controlled inter alia for age and deprivation, diabetes status was negatively related to restoration, extraction, prevention, and total service use. In the analysis of the COVID period, pre-COVID prevention was negatively related to extractions, restorations, prevention and services in general. CONCLUSION: The relationship between maternal diabetic status and aspects of offspring use of dental services was contrary to that suggested in previous studies and warrants more detailed investigation using this valuable data resource.

4.
Trials ; 23(1): 679, 2022 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-35982457

RESUMO

BACKGROUND: Dental service provision in the care home sector is poor, with little emphasis on prevention. Emerging evidence suggests that the use of Dental Care Professionals (dental therapists and dental nurses) as an alternative to dentists has the potential to improve preventive advice, the provision of care and access to services within care homes. However, robust empirical evidence from definitive trials on how to successfully implement and sustain these interventions within care homes is currently lacking. The aim of the study is to determine whether Dental Care Professionals could reduce plaque levels of dentate older adults (65 + years) residing in care homes. METHODS: This protocol describes a two-arm cluster-randomised controlled trial that will be undertaken in care homes across Wales, Northern Ireland and England. In the intervention arm, the dental therapists will visit the care homes every 6 months to assess and then treat eligible residents, where necessary. All treatment will be conducted within their Scope of Practice. Dental nurses will visit the care homes every month for the first 3 months and then three-monthly afterwards to promulgate advice to improve the day-to-day prevention offered to residents by carers. The control arm will be 'treatment as usual'. Eligible care homes (n = 40) will be randomised based on a 1:1 ratio (20 intervention and 20 control), with an average of seven residents recruited in each home resulting in an estimated sample of 280. Assessments will be undertaken at baseline, 6 months and 12 months and will include a dental examination and quality of life questionnaires. Care home staff will collect weekly information on the residents' oral health (e.g. episodes of pain and unscheduled care). The primary outcome will be a binary classification of the mean reduction in Silness-Löe Plaque Index at 6 months. A parallel process evaluation will be undertaken to explore the intervention's acceptability and how it could be embedded in standard practice (described in a separate paper), whilst a cost-effectiveness analysis will examine the potential long-term costs and benefits of the intervention. DISCUSSION: This trial will provide evidence on how to successfully implement and sustain a Dental Care Professional-led intervention within care homes to promote access and prevention. TRIAL REGISTRATION: ISRCTN16332897 . Registered on 3 December 2021.


Assuntos
Saúde Bucal , Qualidade de Vida , Idoso , Cuidadores , Análise Custo-Benefício , Humanos , Ensaios Clínicos Controlados Aleatórios como Assunto , Inquéritos e Questionários
5.
Pharm Res ; 28(10): 2589-98, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21614633

RESUMO

PURPOSE: The pH discrepancy between healthy and atopic dermatitis skin was identified as a site-specific trigger for delivering hydrocortisone from microcapsules. METHODS: Using Eudragit L100, a pH-responsive polymer which dissolves at pH 6, hydrocortisone-loaded microparticles were produced by oil-in-oil microencapsulation or spray drying. Release and permeation of hydrocortisone from microparticles alone or in gels was assessed, and preliminary stability data was determined. RESULTS: Drug release from microparticles was pH-dependent, though the particles produced by spray drying also gave significant non-pH-dependent burst release, resulting from their porous nature or from drug enrichment on the surface of these particles. This pH-responsive release was maintained upon incorporation of the oil-in-oil microparticles into Carbopol- and HPMC-based gel formulations. In vitro studies showed 4- to 5-fold higher drug permeation through porcine skin from the gels at pH 7 compared to pH 5. CONCLUSIONS: Permeation studies showed that the oil-in-oil-generated particles deliver essentially no drug at normal (intact) skin pH (5.0-5.5) but that delivery can be triggered and targeted to atopic dermatitis skin where the pH is elevated. The incorporation of these microparticles into Carbopol- and HPMC-based aqueous gel formulations demonstrated good stability and pH-responsive permeation into porcine skin.


Assuntos
Hidrocortisona/administração & dosagem , Hidrocortisona/química , Dermatopatias/tratamento farmacológico , Dermatopatias/metabolismo , Pele/efeitos dos fármacos , Pele/metabolismo , Resinas Acrílicas , Administração Tópica , Animais , Cápsulas/administração & dosagem , Cápsulas/química , Química Farmacêutica/métodos , Composição de Medicamentos/métodos , Sistemas de Liberação de Medicamentos/métodos , Géis/administração & dosagem , Géis/química , Concentração de Íons de Hidrogênio , Tamanho da Partícula , Permeabilidade/efeitos dos fármacos , Polímeros/química , Polivinil/administração & dosagem , Polivinil/química , Absorção Cutânea/efeitos dos fármacos , Solubilidade , Suínos
6.
BMC Oral Health ; 11: 27, 2011 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-21985746

RESUMO

BACKGROUND: Dental caries is a persistent public health problem with little change in the prevalence in young children over the last 20 years. Once a child contracts the disease it has a significant impact on their quality of life. There is good evidence from Cochrane reviews including trials that fluoride varnish and regular use of fluoride toothpaste can prevent caries. The Northern Ireland Caries Prevention in Practice Trial (NIC-PIP) trial will compare the costs and effects of a caries preventive package (fluoride varnish, toothpaste, toothbrush and standardised dental health education) with dental health education alone in young children. METHODS/DESIGN: A randomised controlled trial on children initially aged 2 and 3 years old who are regular attenders at the primary dental care services in Northern Ireland. Children will be recruited and randomised in dental practices. Children will be randomised to the prevention package of both fluoride varnish (twice per year for three years), fluoride toothpaste (1,450 ppm F) (supplied twice per year), a toothbrush (supplied twice a year) or not; both test and control groups receive standardised dental health education delivered by the dentist twice per year. Randomisation will be conducted by the Belfast Trust Clinical Research Support Centre ([CRSC] a Clinical Trials Unit). 1200 participants will be recruited from approximately 40 dental practices. Children will be examined for caries by independent dental examiners at baseline and will be excluded if they have caries. The independent dental examiners will examine the children again at 3 years blinded to study group.The primary end-point is whether the child develops caries (cavitation into dentine) or not over the three years. One secondary outcome is the number of carious surfaces in the primary dentition in children who experience caries. Other secondary outcomes are episodes of pain, extraction of primary teeth, other adverse events and costs which will be obtained from parental questionnaires. DISCUSSION: This is a pragmatic trial conducted in general dental practice. It tests a composite caries prevention intervention, which represents an evidence based approach advocated by current guidance from the English Department of Health which is feasible to deliver to all low risk (caries free) children in general dental practice. The trial will provide valuable information to policy makers and clinicians on the costs and effects of caries prevention delivered to young children in general dental practice. TRIAL REGISTRATION: EudraCT No: 2009 - 010725 - 39 ISRCTN: ISRCTN36180119 Ethics Reference No: 09/H1008/93:


Assuntos
Assistência Odontológica para Crianças/economia , Cárie Dentária/prevenção & controle , Atenção Primária à Saúde/economia , Cariostáticos/economia , Cariostáticos/uso terapêutico , Pré-Escolar , Cárie Dentária/economia , Fluoretos Tópicos/economia , Fluoretos Tópicos/uso terapêutico , Seguimentos , Educação em Saúde Bucal/economia , Humanos , Irlanda do Norte , Odontologia Preventiva/economia , Escovação Dentária/economia , Escovação Dentária/instrumentação , Cremes Dentais/economia , Cremes Dentais/uso terapêutico , Resultado do Tratamento
7.
Trials ; 21(1): 599, 2020 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-32611443

RESUMO

BACKGROUND: Oral healthcare service provision for dependent older adults is often poor. For dental services to provide more responsive and equitable care, evidence-based approaches are needed. To facilitate future research, the development and application of a core outcome set would be beneficial. The aim of this study is to develop a core outcome set for oral health services research involving dependent older adults. METHODS: A multi-step process involving consensus methods and including key stakeholders will be undertaken. This will involve identifying potentially relevant outcomes through a systematic review of previous studies examining the effectiveness of strategies to prevent oral disease in dependent older adults, combined with semi-structured interviews with key stakeholders. Stakeholders will include dependent older adults, family members, carers, care-home managers, health professionals, researchers, dental commissioners and policymakers. To condense and prioritise the long list of outcomes generated by the systematic review and semi-structured interviews, a Delphi survey consisting of several rounds with key stakeholders, as mentioned above, will be undertaken. The 9-point Likert scale proposed by the GRADE Working Group will facilitate this consensus process. Following the Delphi survey, a face-to-face consensus meeting with key stakeholders will be conducted where the stakeholders will anonymously vote and decide on what outcomes should be included in the finalised core outcome set. DISCUSSION: Developing a core set of outcomes that are clinically and patient-centred will help improve the design, conduct and reporting of oral health services research involving dependent older adults, and ultimately strengthen the evidence base for high-quality oral health care for dependent older adults. TRIAL REGISTRATION: The study was registered with the COMET initiative on 9 January 2018 http://www.cometinitiative.org/studies/details/1081?result=true .


Assuntos
Ensaios Clínicos como Assunto , Técnica Delphi , Serviços de Saúde Bucal , Determinação de Ponto Final , Pesquisa sobre Serviços de Saúde , Fatores Etários , Idoso , Consenso , Humanos , Projetos de Pesquisa , Participação dos Interessados , Revisões Sistemáticas como Assunto , Resultado do Tratamento
8.
Community Dent Oral Epidemiol ; 46(3): 251-257, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29271079

RESUMO

OBJECTIVES: The NICPIP trial evaluated the costs and effects of a caries prevention intervention delivered to 2- to 3-year-old children attending dental practices in Northern Ireland. This supplementary study explored the oral health behaviours of children and their parents to help understand the reasons for the trial's findings. METHODS: A mixed methods study that included a questionnaire completed by all parents (n = 1058) at the time they brought their child for the NICPIP final clinical assessment. The questionnaire collected data on frequency of toothbrushing and sugar consumption. Questionnaire data were analysed by trial group and caries status. Parents of trial participants (n = 42) were invited to take part in telephone interviews. Parents were purposively sampled according to trial group and whether or not their child developed caries. The interviews explored how and why oral health behaviours happened. Interview data were audio-recorded, transcribed verbatim and analysed thematically. RESULTS: The questionnaire data indicated that toothbrushing and between-meal sugar snacking were common in the majority of children. The children of parents who automatically reminded their child to brush their teeth were more likely to remain caries-free (Odds Ratio 1.24; 95% CI 1.08, 1.41; P = .002). Frequency of sweet drink consumption was associated with the child developing caries (Odds Ratio 0.88; 95% CI 0.79, 0.98; P = .021). The interview data showed that parents had positive attitudes towards brushing both in terms of perceived importance and expected outcomes. Attitudes towards sugar snacking were more complex, with parents reporting difficulties in controlling this behaviour. Sugar was described as being something that was "ever present" in children's lives. CONCLUSIONS: Toothbrushing was widely adopted from a young age, but between-meal sugar consumption was highly prevalent. The results suggest that effective family-level and population-level interventions are needed to reduce sugar consumption if substantial improvements in caries prevention are to be achieved.


Assuntos
Assistência Odontológica para Crianças/organização & administração , Cárie Dentária/prevenção & controle , Comportamentos Relacionados com a Saúde , Pais/psicologia , Adulto , Pré-Escolar , Índice CPO , Açúcares da Dieta , Feminino , Humanos , Lactente , Entrevistas como Assunto , Masculino , Irlanda do Norte , Inquéritos e Questionários , Escovação Dentária/estatística & dados numéricos
9.
Health Technol Assess ; 20(71): 1-96, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27685609

RESUMO

BACKGROUND: Dental caries is the most common disease of childhood. The NHS guidelines promote preventative care in dental practices, particularly for young children. However, the cost-effectiveness of this policy has not been established. OBJECTIVE: To measure the effects and costs of a composite fluoride intervention designed to prevent caries in young children attending dental services. DESIGN: The study was a two-arm, parallel-group, randomised controlled trial, with an allocation ratio of 1 : 1. Randomisation was by clinical trials unit, using randomised permuted blocks. Children/families were not blinded; however, outcome assessment was blinded to group assessment. SETTING: The study took place in 22 NHS dental practices in Northern Ireland, UK. PARTICIPANTS: The study participants were children aged 2-3 years, who were caries free at baseline. INTERVENTIONS: The intervention was composite in nature, comprising a varnish containing 22,600 parts per million (p.p.m.) fluoride, a toothbrush and a 50-ml tube of toothpaste containing 1450 p.p.m. fluoride; plus standardised, evidence-based prevention advice provided at 6-monthly intervals over 3 years. The control group received the prevention advice alone. MAIN OUTCOME MEASURES: The primary outcome measure was conversion from caries-free to caries-active states. Secondary outcome measures were the number of decayed, missing or filled tooth surfaces in primary dentition (dmfs) in caries-active children, the number of episodes of pain, the number of extracted teeth and the costs of care. Adverse reactions (ARs) were recorded. RESULTS: A total of 1248 children (624 randomised to each group) were recruited and 1096 (549 in the intervention group and 547 in the control group) were included in the final analyses. A total of 87% of the intervention children and 85% of control children attended every 6-month visit (p = 0.77). In total, 187 (34%) children in the intervention group converted to caries active, compared with 213 (39%) in the control group [odds ratio (OR) 0.81, 95% confidence interval (CI) 0.64 to 1.04; p = 0.11]. The mean number of tooth surfaces affected by caries was 7.2 in the intervention group, compared with 9.6 in the control group (p = 0.007). There was no significant difference in the number of episodes of pain between groups (p = 0.81). However, 164 out of the total of 400 (41%) children who converted to caries active reported toothache, compared with 62 out of 696 (9%) caries-free children (OR 7.1 95% CI 5.1 to 9.9; p < 0.001). There was no statistically significant difference in the number of teeth extracted in caries-active children (p = 0.95). Ten children in the intervention group had ARs of a minor nature. The average direct dental care cost was £155.74 for the intervention group and £48.21 for the control group over 3 years (p < 0.05). The mean cost per carious surface avoided over the 3 years was estimated at £251.00. LIMITATIONS: The usual limitations of a trial such as generalisability and understanding the underlying reasons for the outcomes apply. There is no mean willingness-to-pay threshold available to enable assessment of value for money. CONCLUSIONS: A statistically significant effect could not be demonstrated for the primary outcome. Once caries develop, pain is likely. There was a statistically significant difference in dmfs in caries-active children in favour of the intervention. Although adequately powered, the effect size of the intervention was small and of questionable clinical and economic benefit. FUTURE WORK: Future work should assess the caries prevention effects of interventions to reduce sugar consumption at the population and individual levels. Interventions designed to arrest the disease once it is established need to be developed and tested in practice. TRIAL REGISTRATION: Current Controlled Trials ISRCTN36180119 and EudraCT 2009-010725-39. FUNDING: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 20, No. 71. See the NIHR Journals Library website for further project information.


Assuntos
Assistência Odontológica/organização & administração , Cárie Dentária/prevenção & controle , Fluoretos Tópicos/administração & dosagem , Fluoretos Tópicos/economia , Pré-Escolar , Análise Custo-Benefício , Assistência Odontológica/economia , Feminino , Humanos , Masculino , Irlanda do Norte , Método Simples-Cego , Medicina Estatal , Escovação Dentária/economia , Escovação Dentária/métodos , Cremes Dentais/administração & dosagem , Cremes Dentais/economia
10.
Conserv Physiol ; 1(1): cot015, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-27293599

RESUMO

The live release of wild adult Pacific salmon (Oncorhynchus spp.) following capture is a management tactic often used in commercial, aboriginal, and recreational fisheries. Fisheries capture and handling can be both exhausting and stressful to fish, which can limit their ability to swim and survive after release. As a result, researchers have assessed methods intended to improve post-release survival by assisting the flow of water over the gills of fish prior to release. Such approaches use recovery bags or boxes that direct water over the gills of restrained fish. This study evaluated a method of assisting ventilation that mimics one often employed by recreational anglers (i.e. holding fish facing into a current). Under laboratory conditions, wild Fraser River sockeye salmon (Oncorhynchus nerka) either received manual ventilation assistance for 1 min using a jet of water focused at the mouth or were left to recover unassisted following a capture-and-release simulation. A control group consisted of fish that were not exposed to the simulation or ventilation assistance. The experiment was conducted at 16 and 21°C, average and peak summer water temperatures for the Fraser River, and fish survival was monitored for 33 days. At 21°C, all fish perished within 3 days after treatment in all experimental groups, highlighting the consequences of handling adult sockeye salmon during elevated migration temperatures. Survival was higher at 16°C, with fish surviving on average 15-20 days after treatment. At 16°C, the capture-and-release simulation and ventilation assistance did not affect the survival of males; however, female survival was poor after the ventilation assistance compared with the unassisted and control groups. Our results suggest that the method of ventilation assistance tested in this study may not enhance the post-release survival of adult Fraser River sockeye salmon migrating in fresh water.

11.
Community Dent Oral Epidemiol ; 40(1): 70-9, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22077143

RESUMO

OBJECTIVES: To examine socio-economic variations in the use of publicly funded general dental practitioner care by adolescents under a fee for service arrangement. METHOD: Publicly funded general practitioner reimbursement data were linked to census and vital statistics data within the Northern Ireland Longitudinal Study. Data relate to 12,846 adolescents aged 11 or 12 in April 2003 included within the Northern Ireland Longitudinal Study (28% of the population). The main outcome measure was consumption of dental care between 2003/2004 and 2007/2008 by socio-economic status (as measured by National Statistics Socio-economic Classification of occupation and highest educational attainment of household reference person). RESULTS: In multivariate analysis, socio-economic status was a significant determinant of dental care consumed. Those of the lowest socio-economic status, according to both occupation and highest educational attainment of household reference person, were less likely to have consumed orthodontics OR 0.76 (0.62, 0.95) and OR 0.79 (0.69, 0.91), respectively. Those of lower socio-economic status were, however, more likely to have undergone an extraction and restorative treatment and also consumed on average more treatment than those of higher socio-economic status. CONCLUSION: A demand-led service, in which practitioners are reimbursed in part on a fee for service basis, may create incentives that contribute to different patterns of utilization between social groups. Such a system may not be providing equal access for equal need and may widen existing socio-economic disparities in oral health among adolescents.


Assuntos
Assistência Odontológica/economia , Planos de Pagamento por Serviço Prestado/economia , Medicina Estatal/economia , Adolescente , Criança , Feminino , Disparidades em Assistência à Saúde/economia , Disparidades em Assistência à Saúde/estatística & dados numéricos , Humanos , Modelos Logísticos , Estudos Longitudinais , Masculino , Análise Multivariada , Irlanda do Norte , Fatores Socioeconômicos , Medicina Estatal/estatística & dados numéricos
12.
J Pharm Sci ; 100(2): 566-79, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20799364

RESUMO

During spray drying, emphasis is placed on process optimisation to generate favourable particle morphological and flow properties. The effect of the initial feed solution composition on the drug release from the prepared microparticles (MPs) is rarely considered. We investigated the effects of solvent composition, feed solution concentration and drug-loading on sodium salicylate, hydrocortisone and triamcinolone release from spray-dried Eudragit L100 MPs. Eudragit L100 is a pH-responsive polymer whose dissolution threshold is pH 6 so dissolution testing of the prepared MPs at pH 5 and 1.2 illustrated non-polymer controlled burst release. Increasing the water content of the initial ethanolic feed solution significantly reduced hydrocortisone burst release at pH 5, as did reducing the feed solution concentration. These findings caution that changes in feed solution concentration or solvent composition not only affect particles' morphological characteristics but can also negatively alter their drug release properties. This work also illustrate that drug-free MPs can have different morphological properties to drug-loaded MPs. Therefore, process optimisation needs to be carried out using drug-loaded systems. Depending on the physicochemical properties of the encapsulated active pharmaceutical ingredient (API), drug-loading can affect the polymer solubility in the initial feed solution with consequent impact on MPs morphological and release properties.


Assuntos
Anti-Inflamatórios/administração & dosagem , Preparações de Ação Retardada/química , Hidrocortisona/administração & dosagem , Ácidos Polimetacrílicos/química , Salicilato de Sódio/administração & dosagem , Triancinolona/administração & dosagem , Dessecação , Concentração de Íons de Hidrogênio , Microesferas , Solubilidade , Solventes/química
13.
J Pharm Pharmacol ; 63(9): 1141-55, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21827486

RESUMO

OBJECTIVES: Microencapsulation of drugs into preformed polymers is commonly achieved through solvent evaporation techniques or spray drying. We compared these encapsulation methods in terms of controlled drug release properties of prepared microparticles and investigated the underlying mechanisms responsible for the 'burst release' effect. METHODS: Using two different pH-responsive polymers with a dissolution threshold of pH 6 (Eudragit L100 and AQOAT AS-MG), hydrocortisone, a model hydrophobic drug, was incorporated into microparticles below and above its solubility within the polymer matrix. KEY FINDINGS: Although, spray drying was an attractive approach due to rapid particle production and relatively low solvent waste, the oil-in-oil microencapsulation method was superior in terms of controlled drug release properties from the microparticles. Slow solvent evaporation during the oil-in-oil emulsification process allowed adequate time for drug and polymer redistribution in the microparticles and reduced uncontrolled drug burst release. Electron microscopy showed that this slower manufacturing procedure generated nonporous particles whereas thermal analysis and X-ray diffractometry showed that drug loading above the solubility limit of the drug in the polymer generated excess crystalline drug on the surface of the particles. Raman spectral mapping illustrated that drug was homogeneously distributed as a solid solution in the particles when loaded below saturation in the polymer with consequently minimal burst release. CONCLUSIONS: Both the manufacturing method (which influenced particle porosity and density) and drug:polymer compatibility and loading (which affected drug form and distribution) were responsible for burst release seen from our particles.


Assuntos
Preparações de Ação Retardada/química , Portadores de Fármacos/química , Composição de Medicamentos/métodos , Hidrocortisona/administração & dosagem , Polímeros/química , Cristalização , Dessecação/métodos , Esquema de Medicação , Emulsões , Concentração de Íons de Hidrogênio , Interações Hidrofóbicas e Hidrofílicas , Microesferas , Óleos , Ácidos Polimetacrílicos/química , Porosidade , Soluções , Solventes/química
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