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1.
PLOS Glob Public Health ; 3(7): e0001654, 2023.
Article in English | MEDLINE | ID: mdl-37486898

ABSTRACT

We sought to evaluate the impact of transitioning a multi-country HIV training program from in-person to online by comparing digital training approaches implemented during the pandemic with in-person approaches employed before COVID-19. We evaluated mean changes in pre-and post-course knowledge scores and self-reported confidence scores for learners who participated in (1) in-person workshops (between October 2019 and March 2020), (2) entirely asynchronous, Virtual Workshops [VW] (between May 2021 and January 2022), and (3) a blended Online Course [OC] (between May 2021 and January 2022) across 16 SSA countries. Learning objectives and evaluation tools were the same for all three groups. Across 16 SSA countries, 3023 participants enrolled in the in-person course, 2193 learners participated in the virtual workshop, and 527 in the online course. The proportions of women who participated in the VW and OC were greater than the proportion who participated in the in-person course (60.1% and 63.6%, p<0.001). Nursing and midwives constituted the largest learner group overall (1145 [37.9%] vs. 949 [43.3%] vs. 107 [20.5%]). Across all domains of HIV knowledge and self-perceived confidence, there was a mean increase between pre- and post-course assessments, regardless of how training was delivered. The greatest percent increase in knowledge scores was among those participating in the in-person course compared to VW or OC formats (13.6% increase vs. 6.0% and 7.6%, p<0.001). Gains in self-reported confidence were greater among learners who participated in the in-person course compared to VW or OC formats, regardless of training level (p<0.001) or professional cadre (p<0.001). In this multi-country capacity HIV training program, in-person, online synchronous, and blended synchronous/asynchronous strategies were effective means of training learners from diverse clinical settings. Online learning approaches facilitated participation from more women and more diverse cadres. However, gains in knowledge and clinical confidence were greater among those participating in in-person learning programs.

2.
BMC Med Educ ; 20(1): 499, 2020 Dec 09.
Article in English | MEDLINE | ID: mdl-33298029

ABSTRACT

BACKGROUND: With funding from the United States Health Resources Service Administration (HRSA), a consortium of health professional training institutions from Africa developed HIV-specific, interprofessional, team-based educational resources to better support trainees during the transition period between pre-service training and professional practice. METHODS: Ten faculty members representing nine medical and nursing schools in sub-Saharan Africa (SSA) developed a training package of modules focused on core clinical, public health, interprofessional education (IPE), and quality improvement (QI) domains related to HIV service delivery. Curriculum development was informed by a rapid needs assessment of existing tools and future needs for HIV education across 27 SSA health professions training institutions. A total of 17 modules were developed, targeted at newly qualified health care professionals to be taught in a series of two-day workshops meant to complement existing institution specific HIV-curricula. RESULTS: Between April and July 2019, a comprehensive case-based HIV training package was developed to support trainees in transition from pre-service training to independent professional practice. Each module, addressing different elements of interprofessional practice, was intended to be delivered in an interprofessional format. Thus far, 70 health professions training institutions in 14 countries have implemented the program; 547 educators facilitated STRIPE workshops, with a total of 5027 learners trained between September 2019 and September 2020. CONCLUSIONS: To our knowledge this is the first IPE HIV-specific curriculum explicitly focused on enhancing the quality of training provided to graduating health care professionals working in SSA. The collaborative, cross-institutional, interprofessional approach to curriculum development provides a benchmark for how best-practice approaches to education can be disseminated in SSA.


Subject(s)
Curriculum , Health Occupations , Africa South of the Sahara , Faculty , Health Personnel/education , Humans , Interprofessional Relations
3.
S Afr Med J ; 110(10): 973-981, 2020 08 26.
Article in English | MEDLINE | ID: mdl-33205723

ABSTRACT

The SARS-CoV-2 pandemic has presented clinicians with an enormous challenge in managing a respiratory virus that is not only capable of causing severe pneumonia and acute respiratory distress syndrome, but also multisystem disease. The extraordinary pace of clinical research, and particularly the surge in adaptive trials of new and repurposed treatments, have provided rapid answers to questions of whether such treatments work, and has resulted in corticosteroids taking centre stage in the management of hospitalised patients requiring oxygen support. Some treatment modalities, such as the role of anticoagulation to prevent and treat potential thromboembolic complications, remain controversial, as does the use of high-level oxygen support, outside of an intensive care unit setting. In this paper, we describe the clinical management of COVID-19 patients admitted to Groote Schuur Hospital, a major tertiary level hospital at the epicentre of South Africa's SARS-CoV-2 epidemic during its first 4 months.


Subject(s)
Coronavirus Infections/therapy , Hospitals, University/organization & administration , Pneumonia, Viral/therapy , Tertiary Care Centers/organization & administration , Adrenal Cortex Hormones/therapeutic use , Anticoagulants/therapeutic use , Antimicrobial Stewardship , Betacoronavirus , COVID-19 , Coronavirus Infections/complications , Coronavirus Infections/diagnosis , Coronavirus Infections/psychology , Critical Care/organization & administration , Diabetes Complications , Humans , Intubation, Intratracheal , Medical Staff, Hospital/psychology , Oxygen Inhalation Therapy , Palliative Care , Pandemics , Patient Care Team , Pneumonia, Viral/complications , Pneumonia, Viral/diagnosis , Pneumonia, Viral/psychology , Respiration, Artificial , Risk Factors , SARS-CoV-2 , Social Support , South Africa/epidemiology
5.
S Afr Med J ; 109(8): 592-596, 2019 Jul 26.
Article in English | MEDLINE | ID: mdl-31456555

ABSTRACT

BACKGROUND: Little is known about the current clinical profile and outcomes of patients with infective endocarditis (IE) in South Africa (SA). OBJECTIVES: To provide a contemporary and descriptive overview of IE in a representative SA tertiary centre. METHODS: We conducted a retrospective review of the records of patients admitted to Groote Schuur Hospital, Cape Town, between 2009 and 2016 fulfilling universal criteria for definite or possible IE, in search of demographic, clinical, microbiological, echocardiographic, treatment and outcome information. RESULTS: A total of 105 patients fulfilled the modified Duke criteria for IE. The median age of the cohort was 39 years (interquartile range (IQR) 29 - 51), with a male preponderance (61.9%). The majority of the patients (72.4%) had left-sided native valve endocarditis, 14.3% had right-sided disease, and 13.3% had prosthetic valve endocarditis. A third of the cohort had rheumatic heart disease. Although 41.1% of patients with left-sided disease had negative blood cultures, the three most common organisms cultured in this subgroup were Staphylococcus aureus (18.9%), Streptococcus spp. (16.7%) and Enterococcus spp. (6.7%). Participants with right-sided endocarditis were younger (29 years, IQR 27 - 37) and were mainly intravenous drug users (73.3%), and the majority cultured positive for S. aureus (73.3%) with frequent septic pulmonary complications (40.0%). The overall in-hospital mortality was 16.2%, with no deaths in the group with right-sided endocarditis. Predictors of death in our patients were heart failure (odds ratio (OR) 8.16, 95% confidence interval (CI) 1.77 - 37.70; p=0.007) and age >45 years (OR 4.73, 95% CI 1.11 - 20.14; p=0.036). Valve surgery was associated with a reduction in mortality (OR 0.09, 95% CI 0.02 - 0.43; p=0.001). CONCLUSIONS: IE remains an important clinical problem in a typical teaching tertiary care centre in SA. In this setting, it continues to affect mainly young people with post-inflammatory valve disease and congenital heart disease. The in-hospital mortality associated with IE remains high. Intravenous drug-associated endocarditis caused by S. aureus is an important IE subset, comprising ~10% of all cases, which was not reported 15 years ago, and culture-negative endocarditis remains highly prevalent. Heart failure in IE carries a significant risk of death and needs a more intensive level of care in hospital. Finally, cardiac surgery was associated with reduced mortality, with the largest impact in patients with heart failure.


Subject(s)
Endocarditis, Bacterial/epidemiology , Endocarditis, Bacterial/microbiology , Adult , Age Factors , Drug Users , Endocarditis, Bacterial/therapy , Female , Heart Failure/mortality , Heart Valve Diseases/epidemiology , Heart Valve Prosthesis/adverse effects , Hospital Mortality , Humans , Male , Middle Aged , Prosthesis-Related Infections/epidemiology , Prosthesis-Related Infections/microbiology , Prosthesis-Related Infections/therapy , Retrospective Studies , Rheumatic Heart Disease/epidemiology , South Africa/epidemiology , Substance Abuse, Intravenous/epidemiology
6.
S Afr Med J ; 108(10): 852-857, 2018 Oct 02.
Article in English | MEDLINE | ID: mdl-30421714

ABSTRACT

BACKGROUND: Much has been published on whether newly graduated doctors are ready for practice, seeking to understand how to better prepare graduates for the workplace. Most studies focus on undergraduate education as preparation for internship by investigating knowledge and skills in relation to clinical proficiencies. The conversion from medical student to internship, however, is influenced not only by medical competencies, but also by personal characteristics and organisational skills. Most research focuses largely on the interns' own perceptions of their preparation. Supervisors who work closely with interns could therefore present alternative perspectives. OBJECTIVES: To explore the views of medical intern supervisors on the internship training context, as well as their perspectives on attributes that would help an intern to function optimally in the public health sector in South Africa (SA). This article intends to extend our current understanding of what contributes to a successful internship by including the views of internship supervisors. METHODS: Twenty-seven semi-structured interviews were held with medical intern supervisors in 7 of the 9 provinces of SA. The data were thematically analysed and reported using an existing framework, the Work Readiness Scale. RESULTS: The intern supervisors indicated that interns were challenged by the transition from student to doctor, having to adapt to a new environment, work long hours and deal with a large workload. Clinical competencies, as well as attributes related to organisational acumen, social intelligence and personal characteristics, were identified as being important to prepare interns for the workplace. Diligence, reliability, self-discipline and a willingness to work ('go the extra mile') emerged as key for a 'good' intern. The importance of organisational skills such as triage, prioritisation and participation was foregrounded, as were social skills such as teamwork and adaptability. CONCLUSIONS: This article contributes to our understanding of what makes a successful medical internship by exploring the previously uncanvassed views of intern supervisors who are working at the coalface in the public health sector. It is envisaged that this work will stimulate debate among the medical fraternity on how best to prepare interns for the realities of the workplace. Educational institutions, health services and interns themselves need to take ownership of how to instil, develop and support these important attributes.

7.
Ann Glob Health ; 84(1): 190-197, 2018 04 30.
Article in English | MEDLINE | ID: mdl-30873817

ABSTRACT

BACKGROUND: The Ebola virus epidemic and civil war in Liberia left the country in need of strengthening the health workforce. E-learning in medical education provides relevant learning opportunities for students, develops faculty competencies, and assists with the retention of healthcare workers. The Stellenbosch University Rural Medical Education Partnership Initiative (SURMEPI), the College of Health and Life Sciences (COHLS) at the University of Liberia (UL), and the Health Resources and Services Administration (HRSA) formed a partnership to create an e-learning solution for the COHLS. OBJECTIVE: This article outlines the implementation of an e-learning solution for the COHLS in Monrovia, and describes the challenges met, the key successes achieved, and the lessons learnt. METHODS: An initial scoping visit to Liberia was followed by three further on-site visits. Problems identified were: very limited or no network and computer resources, no internet connection, intermittent power, and lack of IT skills. We followed an evolutionary approach to infrastructure implementation by trying various solutions before settling on an offsite-hosted solution using Software as a Service (SaaS). Local staff were upskilled to administer this while remote support from Stellenbosch IT was provided. A stable internet connection was established. Staff and students can access the Learning Management System (LMS) 24/7 using mobile devices and laptops. Workshops were held where staff were taught how to produce online teaching material. Each class has at least one teaching assistant to assist lecturers with uploading and indexing material on the LMS.A benchmarking visit by COHLS faculty to Stellenbosch University took place, during which an e-learning strategic plan was drawn up. Further online workshops were conducted, and teaching materials were placed on the new LMS. OUTCOMES: The intranet that was established consisted of internet connection and software as a service in the form of Office 365, providing access to several products and services. The e-learning model attended to technology and human resources simultaneously. The e-learning strategy aimed to improve teaching and learning at the COHLS, boost the number of qualified doctors, reduce the workload on lecturers, and be scalable in the future. CONCLUSION: It is challenging to implement e-learning in medical education. Inadequate infrastructure, limited bandwidth, lack of skilled IT staff, unreliable power supply, time commitment, and ongoing maintenance all need to be overcome. The creation of an e-learning solution for the COHLS over a period of 15 months was enabled by the common vision and close collaboration of the three partners. This model can potentially be replicated across other faculties in the University of Liberia and other educational institutions in Liberia.


Subject(s)
Computer-Assisted Instruction/methods , Education, Medical , Medically Underserved Area , Education, Medical/methods , Education, Medical/organization & administration , Education, Medical/standards , Educational Status , Health Workforce/standards , Humans , Internet , Liberia , Models, Educational
8.
Bull Entomol Res ; 106(1): 19-33, 2016 Feb.
Article in English | MEDLINE | ID: mdl-26487373

ABSTRACT

A species in the Bactrocera dorsalis (Hendel) complex was detected in Kenya during 2003 and classified as Bactrocera invadens Drew, Tsuruta & White. Having spread rapidly throughout Africa, it threatens agriculture due to crop damage and loss of market access. In a recent revision of the B. dorsalis complex, B. invadens was incorporated into the species B. dorsalis. The potential distribution of B. dorsalis has been previously modelled. However, previous models were based on presence data and did not incorporate information on the seasonal phenology of B. dorsalis, nor on the possible influence that irrigation may have on its distribution. Methyl eugenol-baited traps were used to collect B. dorsalis in Africa. Seasonal phenology data, measured as fly abundance throughout the year, was related to each location's climate to infer climatic growth response parameters. These functions were used along with African distribution records and development studies to fit the niche model for B. dorsalis, using independent global distribution records outside Africa for model validation. Areas at greatest risk of invasion by B. dorsalis are South and Central America, Mexico, southernmost USA, parts of the Mediterranean coast, parts of Southern and Eastern Australia and New Zealand's North Island. Under irrigation, most of Africa and Australia appear climatically suitable.


Subject(s)
Agriculture , Animal Distribution , Climate , Tephritidae/physiology , Africa , Animals , Models, Theoretical , Population Density
9.
Rural Remote Health ; 14: 2493, 2014.
Article in English | MEDLINE | ID: mdl-24803108

ABSTRACT

INTRODUCTION: Medical education across the globe is in a state of flux influenced by a number of drivers for change. In response, institutions are seeking to re-align their curricula to address the prevailing imperatives. Against this backdrop, the training of practitioners for practice in rural communities was identified as an educational priority, and led to the establishment of a rural clinical school (RCS) within a Faculty of Medicine and Health Sciences in South Africa in 2011. This article describes the students' experiences in the first year that this innovative educational model was implemented and explores the extent to which it influenced their thinking and practice. METHODS: A qualitative, formative evaluation study of the first year of implementation was undertaken. Data was generated from in-depth interviews. This article focuses on individual interviews conducted with the eight students at the RCS, which explored their experiences during a year-long clerkship. Transcripts of interviews were thematically analysed. RESULTS: Four themes emerged from the analysis: a learning experience that differed from what was experienced at the tertiary training hospital, an enabling clinical environment in the district and regional hospital, the positive role played by the specialists, and the influence of the community immersion. Underlying all of the responses was the building of relationships over time both with supervisors and with patients. Evident from the responses was that students' confidence in their clinical skills and decision-making abilities was heightened while their approaches to their own learning were enhanced. CONCLUSIONS: To respond to the call for educational reform and a heightened awareness of social realities, innovative approaches to the training of medical students, such as those adopted at the RCS, are indicated. It is argued that the learning facilitated by these rural medical education models has the potential to offer learning experiences that can lead to transformation through a change in practice and attitude among the students, and ultimately also enable curricular renewal at the institutional core.


Subject(s)
Clinical Clerkship/organization & administration , Education, Medical, Undergraduate/organization & administration , Rural Health Services/organization & administration , Humans , Models, Educational , Problem-Based Learning , Program Evaluation , South Africa , Specialization
10.
Rural Remote Health ; 14: 2511, 2014.
Article in English | MEDLINE | ID: mdl-24803205

ABSTRACT

INTRODUCTION: Studies that investigate the impact of long-term rural exposure for undergraduate medical students often focus largely on students' experiences and perspectives. Research focusing on the physician experience in clinical exposures appears to be limited. When the Ukwanda Rural Clinical School (RCS) at the Faculty of Medicine and Health Sciences, Stellenbosch University, South Africa was implemented in 2011, the clinical specialists working at the rural hospitals were expected to take on the additional task of teaching the students in the year-long rotation. The specialists were prepared for the task through a series of workshops. The objective of this study was to explore what the implementation of the RCS meant for the practice of these physicians and to what extent the shift from full-time practising clinician to clinical teacher required them to adapt and change. METHODS: This was a qualitative study. Semi-structured interviews were conducted with lead clinical specialists who were responsible for teaching medical students in the year-long RCS rotation. Following an interpretive approach, thematic content analysis was performed to obtain a clearer understanding of how these clinicians had experienced their first year as clinical teachers in the RCS. RESULTS: Four overarching themes were identified from the interviews with the clinicians: attitudes towards the implementation of the new medical education model, uncertainty and insecurity as a teacher, emergence of the clinician teacher, and a sense of responsibility for training a future colleague. These depict in part, the journey from clinician to clinician teacher travelled during the first year of implementation. CONCLUSIONS: Embracing the role of clinical teacher enabled the development of constructive relationships between clinicians and their students with a mutual sense of responsibility for learning, patient care and improvement in clinical practice. Understanding this journey ought to influence the thinking of those considering faculty development initiatives for novice clinical teachers.


Subject(s)
Education, Medical, Undergraduate/organization & administration , Faculty, Medical/organization & administration , Medicine , Rural Population , Humans , Models, Educational , Perception , Qualitative Research
11.
Bull Entomol Res ; 103(1): 60-73, 2013 Feb.
Article in English | MEDLINE | ID: mdl-22906299

ABSTRACT

Despite the potential for phenological and abundance data to improve the reliability of species niche models, they are seldom used. The aim of this study was to combine information on the distribution, relative abundance and seasonal phenology of Natal fruit fly, Ceratitis rosa Karsch (Diptera: Tephritidae), in South Africa to model its potential global distribution. Bucket traps, baited with Biolure, were used to trap C. rosa in different climatic regions of South Africa over a two-year period. A CLIMEX niche model of the potential global distribution of C. rosa was fitted using the collected trapping data and other distribution records from South Africa. Independent distribution records for elsewhere in Africa were reserved for model validation. The CLIMEX model results conformed well to the South African trapping data, including information on relative abundance and seasonal phenology, as well as to the pattern of presence records of the species elsewhere in Africa. The model suggests that under recent historical conditions a large part of South America, Central America, Mexico and southern USA may be climatically suitable for establishment of C. rosa. In Europe, climatically suitable habitat is restricted to coastal regions of the Mediterranean, in Asia, mostly to the southern and south eastern countries, and in Australia mostly to the wetter south and east. The independent cross-validation provided by South African relative abundance and seasonal phenology data, central African distribution data and relevant species specific biological information provides greater confidence in the modelled potential distribution of C. rosa.


Subject(s)
Animal Distribution , Tephritidae/physiology , Africa, Central , Animals , Climate , Ecosystem , Models, Biological , South Africa
12.
Med Teach ; 34(12): 1064-9, 2012.
Article in English | MEDLINE | ID: mdl-22957506

ABSTRACT

BACKGROUND: World-wide, rural clinical training of undergraduate medical students is looking to transform learning experiences, calling for the adoption of innovative approaches that create spaces for curriculum renewal and new ways of thinking. In order for these teaching models to gain acceptance and credibility among the relevant academic communities, it is critical that they be studied and evaluated. AIM: This article describes an innovative rural education intervention and a concomitant, intentional process that was adopted to establish a research framework within which the intervention will be evaluated. METHODS: Key role-players participated in a one-day workshop aimed at developing the framework. A collaborative, structured process that moved through three phases of deliberation and reflection was followed. RESULTS: The documentation and raw data generated during the workshop was used to generate the framework that will serve as a blueprint for ensuring the study and evaluation of the educational innovation. CONCLUSION: Establishing an educational research framework, by adopting a consultative and collaborative process, provides a vehicle for encouraging a culture of critical accountability that seeks to discern evidence of good practice in the training of health care workers in a rural context.


Subject(s)
Curriculum , Group Processes , Health Personnel/education , Program Evaluation , Research Design , Rural Health Services , Cooperative Behavior , Education, Medical, Undergraduate , Goals , Humans , Models, Theoretical , South Africa
13.
S Afr J Surg ; 49(1): 36-8, 2011 Mar 14.
Article in English | MEDLINE | ID: mdl-21933482

ABSTRACT

OBJECTIVES: To document the current status of laparoscopic training of paediatric surgical registrars in South Africa. METHODS: An anonymous questionnaire was distributed. Participants were asked to document their involvement in a number of index laparoscopic procedures during the preceding year, as well as additional non-operative training they received and their satisfaction with their training thus far. RESULTS: All registrars (N=16) completed the questionnaire. Registrars were from the Universities of KwaZulu-Natal, Cape Town, Stellenbosch, Pretoria and the Witwatersrand, and Walter Sisulu University. The ratio of consultants proficient in paediatric laparoscopy to registrars was between 0.6 and 1. Junior registrars were more likely to assist with, and senior registrars more likely to perform, procedures. Registrar satisfaction varied greatly across institutions, with 44% of registrars satisfied with their training. CONCLUSIONS: The consultant-to-registrar ratio is favourable, and high patient load provides opportunity for laparoscopic education. However, there are a number of obstacles to adequate training. These include the feasibility of after-hours laparoscopic surgery and the availability and use of training aids. The introduction of a structured training programme across all institutions will improve laparoscopic proficiency and satisfaction among paediatric surgical registrars in South Africa.


Subject(s)
Laparoscopy/education , Laparoscopy/statistics & numerical data , Medical Staff, Hospital , Humans , Pediatrics/education , South Africa
14.
Pharmazie ; 61(7): 595-603, 2006 Jul.
Article in English | MEDLINE | ID: mdl-16889066

ABSTRACT

Suspensions of nifedipine, a practically water-insoluble drug, were prepared in the presence of a biocompatible polymer, polyvinylpyrrolidone (PVP, K value 17), and three surfactants, sodium lauryl sulfate (SLS, anionic), cetyltrimethylammonium bromide (CETAB, cationic), polysorbate 80 (Tween 80, nonionic), by wet milling in ceramic ball mills. Nifedipine powders encapsulated with PVP and the surfactants were recovered from the suspensions after milling and evaluated for changes in particle size, morphology, sedimentation rate in aqueous suspensions, crystal form, and dissolution. Particle size analysis indicated that milling of suspensions in solutions of PVP and surfactants is an efficient method for reducing the particle size of nifedipine to below 10 microm. Furthermore, DSC and XPS analysis indicated that during milling the nifedipine crystals were coated with the PVP or surfactants and that milling with PVP stabilized the nifedipine crystal form during milling while nifedipine was gradually amorphisized when milled in a quaternary nifedipine/PVP/SLS/CETAB system. The decrease in particle size caused a significant decrease in sedimentation rate and increased the dissolution rate of nifedipine in simulated gastric fluid when compared to milled nifedipine and powder mixtures of the drug and the excipients.


Subject(s)
Calcium Channel Blockers/chemistry , Nifedipine/chemistry , Biocompatible Materials , Cetrimonium , Cetrimonium Compounds , Chromatography, High Pressure Liquid , Crystallography, X-Ray , Drug Compounding , Drug Stability , Excipients , Particle Size , Polymers , Polysorbates , Sodium Dodecyl Sulfate , Solubility , Spectrophotometry, Ultraviolet , Surface-Active Agents , Suspensions
15.
Pharmazie ; 61(4): 336-40, 2006 Apr.
Article in English | MEDLINE | ID: mdl-16649550

ABSTRACT

In this study, high sensitivity micro differential scanning calorimetry (MDSC) in the scanning of dynamic mode was compared to X-ray powder diffractometry (XRPD) for quantifying amorphous nifedipine in mixtures crystalline nifedipine. This technique was also compared with FTIR for quantifying polymorph A of chloramphenicol palmitate (CAP) and poly DL-lactide-co-glycolide) (PLGA) in pharmaceutical formulations. The limit of determination (LOD) achieved by MDSC were 0.06% compared to 5% for XRPD quantification of amorphous nifedipine and 0.02% compared to 7% for IR quanitfication of polymorph A of CAP. As little as 0.165 mg PLGA could be measured in excipients mixtures. Desirable linearity and repeatability were established in all cases.


Subject(s)
Calorimetry, Differential Scanning , Pharmaceutical Preparations/analysis , Spectroscopy, Fourier Transform Infrared , X-Ray Diffraction , Chemistry, Pharmaceutical , Chloramphenicol/chemistry , Crystallization , Lactic Acid , Nifedipine/chemistry , Polyglycolic Acid , Polylactic Acid-Polyglycolic Acid Copolymer , Polymers , Reproducibility of Results
16.
Pharmazie ; 61(1): 35-40, 2006 Jan.
Article in English | MEDLINE | ID: mdl-16454204

ABSTRACT

This study reports the formulation, stability, in vitro release and microbicidal activity of a cream, emulsion, foot gel, cover stick and after sun spray containing triclosan. Triclosan is a broad-spectrum antimicrobial agent with activity against a wide range of both gram-negative and gram-positive bacteria that has found increasing popular use in personal care products. These products were stable for up to 3 months when stored at 5, 25, and 40 degrees C. Antimicrobial zone inhibition tests showed that that was a liner relationship, R2 > 0.92, between the release of triclosan from these products and the size of the inhibition zones. This means the in vitro/in vivo correlation for these products was good and that release studies can be used to predict the antimicrobial activity of triclosan.


Subject(s)
Anti-Infective Agents, Local/pharmacology , Bacteria/drug effects , Triclosan/pharmacology , Administration, Topical , Anti-Infective Agents, Local/administration & dosage , Anti-Infective Agents, Local/chemistry , Chemistry, Pharmaceutical , Chromatography, High Pressure Liquid , Drug Stability , Microbial Sensitivity Tests , Pharmaceutical Vehicles , Spectrophotometry, Ultraviolet , Triclosan/administration & dosage , Triclosan/chemistry
17.
Mol Ecol ; 14(14): 4415-26, 2005 Dec.
Article in English | MEDLINE | ID: mdl-16313602

ABSTRACT

We describe a scenario of plant speciation across a relict forest archipelago in South Africa involving Pleistocene habitat expansion-contraction cycles, dispersal and adaptation to lower temperatures. This is the first population level study using molecular data in South African forests and has significant implications for conservation efforts in this area. Populations of the mesophytic forest floor herbs Streptocarpus primulifolius sensu lato and Streptocarpus rexii were sampled throughout their range in the naturally fragmented forests of eastern South Africa in order to investigate population genetic and phylogenetic patterns within the species complex, using nuclear microsatellites, nuclear ribosomal ITS (internal transcribed spacer) sequences and chloroplast genome sequences. S. primulifolius harbours high levels of genetic diversity at both the nuclear (mean HE = 0.50) and the chloroplast level (each population fixed for a unique haplotype). This is consistent with populations of these coastal species being Pleistocene relicts. In contrast, populations of S. rexii in cooler habitats at higher altitudes and lower latitudes harbour little or no nuclear genetic diversity (mean HE = 0.09) and most share a common chloroplast haplotype. The split of S. rexii from populations intermediate between the two species (S. cf. primulifolius) occurred between 0 and 0.44 million years ago according to the calibrated ITS phylogeny of the taxa. The low genetic diversity and homogeneity of S. rexii is congruent with this species having reached its current range during the Holocene. We found no evidence of monophyly of any of the taxa in this study, which we consider a consequence of recent evolution in a fragmented habitat.


Subject(s)
Environment , Genetic Speciation , Genetic Variation , Genetics, Population , Magnoliopsida/genetics , Phylogeny , Conservation of Natural Resources , DNA, Chloroplast/genetics , DNA, Ribosomal Spacer/genetics , Evolution, Molecular , Geography , Haplotypes/genetics , Magnoliopsida/physiology , Microsatellite Repeats/genetics , Population Dynamics , Sequence Analysis, DNA , South Africa
18.
Pharmazie ; 60(4): 278-82, 2005 Apr.
Article in English | MEDLINE | ID: mdl-15881608

ABSTRACT

This study reports the preparation of amoxicillin microcapsules by an emulsion solvent evaporation process. In particular the effect of processing variables including the dimension and position of stirring paddle and container; volume of continuous phase versus dispersion phase; stirring speed and encapsulation temperature on the release and particulate properties of the amoxicillin microcapsules were determined. When the diameter of the paddle was half of that of the container and the clearance between the paddle and the bottom of the vessel was 1/4 of the total volume in the vessel, almost no material stuck to the inside wall of the beaker and uniform microcapsules were prepared. Very uniform, round microcapsules were also prepared with a high yield when V(acetone): V(light mineral oil) = 1 : 3 and 1 : 5 because these systems ensured the formation of uniform emulsions. Physical evaluation of the microcapsules also showed that optimum drug release was achieved when the microcapsules were round, did not aggregate, were protected from the burst effect, the stirring speed for preparation was between 600-800 rpm and evaporation temperature was 25 degrees C. Microcapsules prepared using these ideal conditions achieved constant amoxicillin release for up to 12 h.


Subject(s)
Amoxicillin/administration & dosage , Amoxicillin/chemistry , Penicillins/administration & dosage , Penicillins/chemistry , Capsules , Delayed-Action Preparations , Emulsions , Particle Size , Solvents
19.
Pharmazie ; 59(9): 728-30, 2004 Sep.
Article in English | MEDLINE | ID: mdl-15497761

ABSTRACT

This study reports the incompatibility of sennoside A and B with the following commonly used pharmaceutical excipients: stearic acid, sodium carbonate, glucose, lactose, propyl paraben, sodium carbonate, stearic acid, citric acid, PEG, and sorbitol. Drug-excipient compatibility was tested using thermal (DSC) and analytical (HPLC) methods of analysis. Compatibility evaluation showed that dry powder mixtures could be used to formulate sennoside A and B products. However, when mixed with water--propyl paraben, sodium carbonate, stearic acid, citric acid, PEG, and sugar derivatives such as lactose, glucose and sorbitol--should not be used in sennoside containing products.


Subject(s)
Anthraquinones/chemistry , Calorimetry, Differential Scanning , Chemistry, Pharmaceutical , Chromatography, High Pressure Liquid , Drug Incompatibility , Excipients , Powders , Senna Extract , Sennosides
20.
Pharmazie ; 59(7): 534-40, 2004 Jul.
Article in English | MEDLINE | ID: mdl-15296091

ABSTRACT

This study reports the preparation of four niclosamide solvates and the determination of the stability of the crystal forms in different suspension vehicles by DSC and TG analysis. Thermal analysis showed that the niclosamide solvates were extremely unstable in a PVP-vehicle and rapidly changed to monohydrated crystals. A suspension in propylene glycol was more stable and TG analysis showed that crystal transformation was less rapid. In this vehicle, the crystals transformed to the anhydrate, rather than the monohydrate, since the vehicle was non-aqueous. The TEG-hemisolvate was the most stable in suspension and offered the best possibility of commercial exploitation.


Subject(s)
Anthelmintics/chemistry , Niclosamide/chemistry , Algorithms , Calorimetry, Differential Scanning , Chemical Phenomena , Chemistry, Physical , Crystallization , Crystallography, X-Ray , Dimethyl Sulfoxide/chemistry , Dimethylformamide/chemistry , Drug Stability , Kinetics , Polyethylene Glycols/chemistry , Solutions , Solvents , Suspensions , Thermogravimetry
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