Phaeochromocytoma-associated critical peripheral ischaemia.

Limb Ischaemia is an exceptional complication of catecholamine toxicity caused by a phaeochromocytoma. We present a middle-aged female patient with severe subacute peripheral ishaemia, gangrene and eventual amputation of all four distal limbs due to a large non-metastatic left adrenal gland phaeochromocytoma and summarise the available literature concerning previously reported cases.

Investigating a new approach to film casting for enhanced drug content uniformity in polymeric films.

Films prepared by conventional casting onto trays such as teflon-coated perspex trays (TCPTs) suffer from poor drug content uniformity. The aim of this study was to prepare a silicone-molded tray (SMT) with individual wells for film casting and to evaluate it in terms of enhancing drug content uniformity. Films were prepared by solvent evaporation or emulsification and cast onto TCPT and SMT. Preparation of films by the SMT method was superior in terms of meeting drug content uniformity requirements. As compared with the TCPT method, the SMT casting method also reduced the variability in mucoadhesivity, drug release, and film thickness. Reproducibility of the SMT method was demonstrated in terms of drug content, mucoadhesion, and drug release.

Formulation of monolayered films with drug and polymers of opposing solubilities.

The aim of this study was to prepare and characterise monolayered multipolymeric films (MMFs) comprising of a hydrophilic drug (Propranolol HCl) (PHCl) and polymers of opposing solubilities. Films were prepared by emulsification and casted by a new approach using a silicone-molded tray with individual wells. MMFs comprising of PHCl with Eudragit 100 (EUD100) and Chitosan (CHT), i.e. films with drug and polymers of opposing solubilities were successfully prepared (PHCl:EUD100:CHT; 1:10:0.5) and demonstrated uniform and reproducible drug content (100.71+/-2.66%), thickness (0.442+/-0.030 mm), mucoadhesivity (401.40+/-30.73 mN) and a controlled drug release profile. Drug release followed Higuchi's square-root model. Maximum swelling of the films occurred after 1h and 28.26% of the films eroded during the 8-h test period. Mechanical testing revealed that the MMFs displayed a greater abrasion resistance, were more elastic and also required more energy to break, rendering them tougher and more suitable for buccal delivery than the monopolymeric PHCl:EUD100 film. The inclusion of CHT to the film led to a more porous surface morphology. The surface pH of the films remained constant at neutral pH. This study confirmed the potential of the above MMFs as a promising candidate for buccal delivery of PHCl.

Family Practitioners Perception of; Knowledge about and use of Peak Flow Meters in Lenasia; Lenasia South; and Soweto Community Health Clinics

Background : The purpose of this paper was to determine the availability of peak flow meters; perceptions about their usefulness and the perceptions of clinical indications for their use. Methods : A questionnaire was administered to private and public sector practitioners (n=72) working in three urban areas of greater Johannesburg. Data were collected concerning practice profiles; the characteristics of the practitioners; the extent of and indications for use; and the reasons for failure to use these meters. Results : The results showed that only 21 (29) of the practitioners advised their asthma patients to use peak flow meters for home monitoring. A scoring system (summary score); which was developed to summarise knowledge of both the indications for the use of the meters and the method of peak flow measurement; showed that only 33.3of the practitioners attained maximum or close to maximum scores (6 to 8 of an 8-point scale). Conclusion : Peak flow meters were underutilised by family practitioners. The cost of the peak flow meter was an important reported cause of underutilisation. It is recommended that the importance of the peak flow meter in the management of asthma be emphasised at the undergraduate and continuing medical education level. The findings of this study could also be used to guide the national campaign coordinators in South Africa in their strategy to improve asthma care among family practitioners. Since asthma may be under-diagnosed in the community; further research is needed to assess the effects of education in assisting people to recognise asthma. Early recognition and diagnosis of asthma; together with appropriate asthma education; may significantly reduce morbidity. The role of illiteracy and cost in limiting the use of peak flow meters warrants investigation; as does the possibility of developing suitable meters for populations with limited formal education. Doctors need to make more conscientious; concerted and informed efforts to monitor their asthma patients and to collaborate; where appropriate; with health educators to optimise the management of asthma. This could include workshops within the community and with fellow healthcare workers (doctors; primary healthcare sisters) on various aspects of asthma care; which will incorporate inhaler techniques and peak flow meter use

Enhancing drug incorporation into tetracycline-loaded chitosan microspheres for periodontal therapy.

PURPOSE: To identify optimal formulation parameters for enhancing the incorporation of tetracycline hydrochloride into chitosan microspheres for periodontal therapy. METHODS: Tetracycline-loaded chitosan microspheres were prepared by ionotropic gelation. Various formulation parameters (salt form of drug, aqueous phase pH, anion structure, inorganic salts and electrolytes, preparation method) were investigated for their influence on drug incorporation efficiency. Microspheres were assessed in terms of drug entrapment and content, microsphere recovery, particle size and morphology. RESULTS: Although drug incorporation efficiency was increased marginally, the use of a dihydrate form of the drug was not considered feasible due to the lowered microsphere recovery and higher costs. A decrease in the aqueous pH from 9 to 6 enhanced drug incorporation efficiency without an adverse effect on microsphere morphology. The use of inorganic salts/electrolytes and other approaches of microsphere preparation did not significantly enhance drug incorporation efficiency and these approaches also adversely affected microsphere morphology. The ionotropic preparation method in terms of the drug loading technique significantly affected drug incorporation efficiencies. CONCLUSIONS: This study has shown that formulation variables can be exploited in order to enhance the incorporation of a water soluble drug into chitosan microspheres using the ionotropic gelation technique. Based on a comparison of all results obtained with the different approaches, the modification of the aqueous phase to pH 6 was identified as the most feasible approach.

Evaluation of the buffering capacity of powdered cow's, goat's and soy milk and non-prescription antacids in the treatment of non-ulcer dyspepsia.

BACKGROUND: Non-ulcer dyspepsia (NUD) is the term most commonly used to describe a heterogeneous and often ill-defined group of dyspepsia patients whose symptoms of upper abdominal pain, discomfort or nausea persist in the absence of identifiable cause. Treatment choice commonly includes over the counter medicines and home remedies, e.g. milk. OBJECTIVE: To determine the relative buffering capacity of goat's, cow's and soy milk, non-prescription antacid drugs and combinations thereof. METHODS: The buffering capacities of 25 ml aliquots of each of the powdered milk products, the antacids alone and the combination of antacid and milk were determined. Statistical analysis was used to determine any significant differences in buffering capacity. RESULTS: When the antacids were examined alone, significant differences in buffering capacity were observed. When powdered milk products were examined alone, cow's milk had a significantly higher buffering capacity than either goat's or soy milk. There was no significant difference between goat's and soy milk. In the combination of cow's milk with each of the antacids, brand A and B had a similar buffering capacity, significantly higher than that observed with brand C. CONCLUSIONS: The combination with best observed buffering capacity was brand A with cow's milk, and the weakest buffering capacity was observed with brand C with soy milk. The results obtained can be attributed to the chemical constituents of the antacids and the milk products.

Formulation of rate-modulating pellets for the release of ibuprofen: an extrusion-spheronization process.

PURPOSE: To develop a stable and reproducible modified release pellet formulation containing ibuprofen. METHODS: Using extrusion-spheronization technology to produce pellets. RESULTS: The percentage yield, size distribution and overall pellet shape within the desired size range of 1000-1400 microm was found to be dependent on various process variables. These include extrusion and spheronization speed, spheronization time and composition of the granulation fluid. Formulation factors such as viscosity grade of hydroxypropylmethylcellulose and concentration of microcrystalline cellulose were shown to influence the drug release rate of the pellets. In vitro dissolution studies revealed that the pellets behaved in a pH-dependent manner. Pellets exposed to different drying techniques exhibited an increase in drug release rate in the order corresponding to oven-dried, vacuum-dried, fluid bed-dried and freeze-dried pellets. In conjunction with scanning electron microscopy, kinetic modelling and statistical treatment of dissolution data, it was confirmed that the predominant release rate-controlling mechanism was diffusion, as evidenced from the power law expressions incorporating Fickian and relaxational parameters (M(t) /M(infinity) = K(1)t(n); M(t) /M(infinity) = K(1)t(2n)). Matrix swelling and erosion were not significant factors in modulating the drug release rate. CONCLUSIONS: The pH-dependent property of the pellets may be strategically employed towards development of a site-specific drug delivery system for non-steroidal anti-inflammatory agents. In general, targeting the delivery of an agent with potential for gastric irritation to the proximal intestine/colon may effectively reduce its ulcerogenic effect and ultimately contribute towards improved patient compliance.