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The research was carried out in collaboration with Freeman Technology Ltd. and Micromeritics UK. open access article This study investigates the relationships between the flow properties of five blends of polyamide 12, with the mechanical and physical characteristics of the fabricated components. The bulk properties and flowability of the powder blends were characterised using powder rheology. Absolute, or skeletal volume of 3D printed cubes were measured using helium pycnometry. The tensile behaviour and surface hardness of specimens fabricated from the five blends were determined. The mechanical properties of the samples were correlated with the flow behaviour of the powder used. Comparison of the powder flow measures with the mechanical properties of the fabricated parts allows for prediction of final product quality prior to printing. Understanding the relationships between these parameters helps to identify and develop powders that enhance both process efficiency and the mechanical properties of the final product.

Study of flow is a key to development of dry powder inhalation formulations. Various static (bulk) and dynamic rheological measurements are used to study different aspects of powder flow and packing. Among rheological measurements, the permeability and the fluidization energy are, conceptually, most relevant to dispersion of dry powder inhalation formulations. The aim of the current study was to test the robustness and the range of applications of the two measurements, among other rheological measurements. To this end, we prepared and studied a series of ternary, carrier-based dry powder inhalation formulations. The formulations were mixtures of coarse-fine excipient (α-lactose monohydrate) blends, with different fine excipient concentrations (0.0-15.0 % w/w), and a spray-dried drug (fluticasone propionate) material. The excipient blends were characterized in terms of morphology, size, crystallinity, and rheological properties. The formulations were evaluated in vitro using a low resistance inhalation device, the Cyclohaler®, and a high resistance inhalation device, the Handihaler®. The study design aimed to complement literature data. Bulk rheological measurements, specifically the bulk density, the compressibility, and the permeability, exhibited satisfactory precision and could demonstrate changes in powder composition and structure. They hold a potential for use as critical material attributes to aid monitoring and optimization of carrier-based dry powder inhalation formulations in quality-by-design systems. On the other hand, dynamic rheological measurements, specifically the basic flowability energy, the specific energy, and the fluidization energy, generally exhibited high variability, which obscured interpretation of the measurements and implied heterogeneous powder structures. The fluidization energy could, nevertheless, convey structural changes taking place during powder fluidization.

This study is part of an ongoing project to enable the full specification of the Design Space for roller compactor systems and shows how the processing parameters influence the behaviour of the product granulate from a placebo formulation. Granulate was produced using a proprietary roller compactor by varying the compaction pressure and gap width, and the dynamic, bulk and shear properties of the resultant granulates were measured. The results demonstrate several rheological properties of the granulate, which have been shown to be closely correlated with variance in die filling and tablet strength, and are predictably influenced by the processing parameters.

Capsules are the most popular and versatile dosage form produced in pharmaceutical compounding. In the preparations of capsules, powder excipients are nonactive ingredients that can be used for the purpose of increasing bulk, enhancing flow, and improving stability of a powder formulation. Flow properties of powder excipients can impact not only the compounding procedure, but also the uniformity and quality of the final product. In this study, an FT4 Powder Rheometer was used to compare dynamic, bulk, and shear properties of the following four powder excipients: Loxoral, Loxasperse, a commercial powder excipient, and lactose monohydrate. Changes in flow energy, measured as the powders are exposed to external conditions such as air, compression, consolidation, and shear forces, were used to compare flow properties of the four excipients. Results show Loxasperse to have superior dynamic properties, indicating more efficient packing potentials. Though Loxoral did not have the most favorable flow in t...

Significant numbers of materials in the food, chemical and pharmaceutical industries, from raw feeds, additives and intermediates through to manufactured products, are sold as free-flowing, easily processable powders. However, for logistical reasons, these materials are often stored for extended periods during processing and some will gain strength during such storage periods due to particle/particle interaction. This is generally referred to as ‘caking’ and can significantly limit the ability of a powder to pass uninterrupted through the process and can detrimentally impact product quality. This paper will evaluate the change flow properties of powders subjected to moisture. It will show how the propensity to cake can be effectively quantified with respect to the powders’ flow properties and how this can assist with understanding and adapting the processing environment to retain optimal processability. Moreover it will show how in some cases caking is not a homogeneous progression and how such non-homogeneity can be evaluated and quantified.

Despite their widespread and well-established use, powders are challenging materials to work with, as evidenced by the common problems encountered during storage and processing, as well as in the quality and consistency of final products. The diverse range of unit operations used to handle and manipulate powders subject them to extremes of stress and flow regimes; from the high stress, static conditions present in hoppers to the dispersed, dynamic state of a fluidised bed dryer. It is therefore possible for a powder to behave a certain way in a given unit operation, but entirely differently in another. Many existing powder testing techniques don’t deliver the required information as the test conditions do not represent the conditions in the process. Modern powder rheometers generate process relevant data by accurately measuring dynamic flow, bulk and shear properties. This approach enables a powder’s response to aeration, consolidation, forced flow and changes in flow rate to be reliably quantified thereby simulating the conditions which a powder will be subjected to in process. This paper provides an introduction to powder rheology, including a comparison with traditional techniques, and uses case studies to demonstrate how powder rheology can be applied to optimise production processes and enhance product quality

Over 70% of materials in the food, chemical, and pharmaceutical industries (from raw materials, additives, and intermediates through to manufactured products) are supplied as relatively free-flowing powders, intended to be suitable for the manufacturing process or final application. For logistical reasons however these materials will often have to be stored for extended periods during which time some powders have the potential to gain strength due to prolonged and undisturbed particle/particle interactions. This is generally referred to as “caking” and can significantly limit the ability of a powder to pass through the process train without interruption as well as detrimentally impacting product quality.This paper will present case studies that evaluate the flow properties of different powder systems that are affected by chemical-, moisture-, and temperature-based caking mechanisms. It will show how the propensity to cake can be effectively quantified with respect to the powders’ flow properties and how t...

Patterns and frequency of anxiety in women undergoing gynaecological surgery\ud Aims. Within a gynaecological surgical setting to identify the patterns and frequency\ud of anxiety pre- and postoperatively; to identify any correlation between raised\ud anxiety levels and postoperative pain; to identify events, from the patients’ perspective,\ud that may increase or decrease anxiety in the pre- and postoperative periods.\ud Background. It is well documented that surgery is associated with increased anxiety,\ud which has an adverse impact on patient outcomes. Few studies have been conducted\ud to obtain the patient’s perspective on the experience of anxiety and the events and\ud situations that aggravate and ameliorate it.\ud Method. The study used a mixed method approach. The sample consisted of women\ud undergoing planned gynaecological surgery. Anxiety was assessed using the State\ud Trait Anxiety Inventory. Trait anxiety was measured at the time of recruitment.\ud State anxiety was then assessed at six time points during the pre- and postoperative\ud periods. Postoperative pain was also measured using a 10 cm visual analogue scale.\ud Taped semi-structured telephone interviews were conducted approximately a week\ud after discharge.\ud Results. State anxiety rose steadily from the night before surgery to the point of\ud leaving the ward to go to theatre. Anxiety then increased sharply prior to the\ud anaesthetic decreasing sharply afterwards. Patients with higher levels of trait anxiety\ud were more likely to experience higher levels of anxiety throughout their admission.\ud Elevated levels of pre- and postoperative anxiety were associated with increased\ud levels of postoperative pain. Telephone interviews revealed a range of events/situations\ud that patients recalled distressing them and many were related to inadequate\ud information.\ud Conclusion. This study found higher rates of anxiety than previously reported and\ud anxiety levels appeared raised before admission to hospital. This has important\ud clinical and research implications.Relevance to clinical practice. Patients with high levels of anxiety may be identified\ud preoperatively and interventions designed to reduce anxiety could be targeted to this\ud vulnerable group. Patient experiences can inform the delivery of services to meet\ud their health needs better.

PurposeThat patients should be able to receive a copy of any letter written about them is part of the British Government's policy to increase patients' involvement in their care and treatment. All National Health Service (NHS) organisations are expected to implement this by April 2005. This paper aims to describe how one acute Trust has used basic change management principles to implement the initiative.Design/methodology/approachExamines the approach of the Salisbury Health Care NHS Trust, where initially a survey of all consultants, senior nurses and allied health professionals was carried out.FindingsInitial concerns that patients would not understand the letter were generally unfounded with 98.9 per cent of patients saying that they understood their letter. Of patients, 96.9 per cent said that they found receiving a copy letter useful.Originality/valueThe research demonstrated a high percentage of patients wanting a copy letter, which has huge resource implications in terms of secretarial time, additional stationery and postage costs. Change is difficult and an emotionally charged issue however, using examples of good practice and taking a multi‐faceted approach to the change process the initiative has been successfully implemented.

A collaborative project between a district hospital and a local university resulted in a senior lecturer being seconded 2 days per week to facilitate the continued improvement in pain management. The rationale for this collaboration was to explore the utilization of innovative teaching methods to deliver education in practice and to develop further research in relation to pain management. An interprofessional pain steering group (IPSG) was established with representation from several services (acute pain, chronic pain, palliative care, physiotherapy, etc.). This group identified several objectives, one of which related to the improvement of pain management through interprofessional education based on the findings from previous audit work. This paper reports on the provision of interprofessional education in pain management and on the evaluation of the impact of this on patient outcomes and practitioner learning. The successes and challenges of this endeavour are discussed.

Improving patients’ postoperative sleep: a randomized control study comparing subcutaneous with intravenous patient-controlled analgesia One hundred female patients undergoing major reconstructive plastic or gynaecological surgery were randomized to either receive subcutaneous patient-controlled analgesia (PCA) (bolus dose 2·5 mg diamorphine in 1 ml with a 20-minute lockout) or intravenous PCA (bolus dose 0·5 mg diamorphine in 1 ml with a 5-minute lockout). Data were collected by questionnaire and interview to evaluate the intervention on pain scores, quality of sleep on the first postoperative night, postoperative nausea and vomiting (PONV) and overall patient acceptability. The subcutaneous PCA group experienced less ‘worse pain’ (P