Design, optimization and characterisation of polymeric microneedle arrays prepared by a novel laser-based micromoulding technique.

PURPOSE: Design and evaluation of a novel laser-based method for micromoulding of microneedle arrays from polymeric materials under ambient conditions. The aim of this study was to optimise polymeric composition and assess the performance of microneedle devices that possess different geometries. METHODS: A range of microneedle geometries was engineered into silicone micromoulds, and their physicochemical features were subsequently characterised. RESULTS: Microneedles micromoulded from 20% w/w aqueous blends of the mucoadhesive copolymer Gantrez® AN-139 were surprisingly found to possess superior physical strength than those produced from commonly used pharma polymers. Gantrez® AN-139 microneedles, 600 µm and 900 µm in height, penetrated neonatal porcine skin with low application forces (>0.03 N per microneedle). When theophylline was loaded into 600 µm microneedles, 83% of the incorporated drug was delivered across neonatal porcine skin over 24 h. Optical coherence tomography (OCT) showed that drug-free 600 µm Gantrez® AN-139 microneedles punctured the stratum corneum barrier of human skin in vivo and extended approximately 460 µm into the skin. However, the entirety of the microneedle lengths was not inserted. CONCLUSION: In this study, we have shown that a novel laser engineering method can be used in micromoulding of polymeric microneedle arrays. We are currently carrying out an extensive OCT-informed study investigating the influence of microneedle array geometry on skin penetration depth, with a view to enhanced transdermal drug delivery from optimised laser-engineered Gantrez® AN-139 microneedles.

A randomized, placebo-controlled trial to evaluate the efficacy, safety, and pharmacodynamic interaction of coadministered amlodipine and atorvastatin in 1660 patients with concomitant hypertension and dyslipidemia: the respond trial.

Guidelines stress the importance of the simultaneous management of multiple cardiovascular risk factors. This can in part be achieved by coadministration of lipid-lowering and antihypertensive treatments. Potential pharmacodynamic interaction between drugs should be investigated as part of developing single-pill combinations. The Respond trial assessed whether combining amlodipine to treat hypertension and atorvastatin to treat dyslipidemia affected the action of either monotherapy. A total of 1660 hypertensive patients with dyslipidemia received 1 of 15 combinations of amlodipine (placebo, 5, or 10 mg) and atorvastatin (placebo, 10, 20, 40, or 80 mg) in a 3 x 5 factorial randomized, placebo-controlled design. At 8 weeks, combination-treated patients experienced dose-related and statistically significant reductions in systolic blood pressure, low-density lipoprotein cholesterol, and Framingham risk score. Overall, coadministered atorvastatin and amlodipine was well tolerated and without adverse pharmacodynamic interaction; combination treatment did not affect the low-density lipoprotein cholesterol-lowering efficacy and safety of atorvastatin, or the systolic blood pressure-lowering efficacy and safety of amlodipine.

Measuring the impact of passenger restrictions on new teenage drivers.

Passenger restrictions for new teenage drivers that became law in 1998 in California provide an opportunity to study the effectiveness of such laws in reducing the number of passengers as well as the influence of teenage passengers on novice drivers. Using fatal and injury crash data from California's Statewide Integrated Traffic Records System, this study found that teenage passengers are a causal factor in crashes of 16-year-old drivers and that in the three years following implementation of the new law, the average number of teenage passengers carried by 16-year-olds decreased by approximately 25%. Without considering the beneficial effect of a decrease in the crash rate, the decrease in the number of teenage passengers in actual crashes resulted in an estimated saving of eight lives and the prevention of 684 injuries over a three-year period.

A model to assess the cost effectiveness of statins in achieving the UK National Service Framework target cholesterol levels.

BACKGROUND: Coronary heart disease (CHD) is a public health priority in the UK. The National Service Framework (NSF) has set standards for the prevention, diagnosis and treatment of CHD, which include the use of cholesterol-lowering agents aimed at achieving targets of blood total cholesterol (TC) < 5.0 mmol/L and low density lipoprotein-cholesterol (LDL-C) < 3.0 mmol/L. In order to achieve these targets cost effectively, prescribers need to make an informed choice from the range of statins available. AIM: To estimate the average and relative cost effectiveness of atorvastatin, fluvastatin, pravastatin and simvastatin in achieving the NSF LDL-C and TC targets. DESIGN: Model-based economic evaluation. METHODS: An economic model was constructed to estimate the number of patients achieving the NSF targets for LDL-C and TC at each dose of statin, and to calculate the average drug cost and incremental drug cost per patient achieving the target levels. The population baseline LDL-C and TC, and drug efficacy and drug costs were taken from previously published data. Estimates of the distribution of patients receiving each dose of statin were derived from the UK national DIN-LINK database. RESULTS: The estimated annual drug cost per 1000 patients treated with atorvastatin was pound 289000, with simvastatin pound 315000, with pravastatin pound 333000 and with fluvastatin pound 167000. The percentages of patients achieving target are 74.4%, 46.4%, 28.4% and 13.2% for atorvastatin, simvastatin, pravastatin and fluvastatin, respectively. Incremental drug cost per extra patient treated to LDL-C and TC targets compared with fluvastatin were pound 198 and pound 226 for atorvastatin, pound 443 and pound 567 for simvastatin and pound 1089 and pound 2298 for pravastatin, using 2002 drug costs. CONCLUSIONS: As a result of its superior efficacy, atorvastatin generates a favourable cost-effectiveness profile as measured by drug cost per patient treated to LDL-C and TC targets. For a given drug budget, more patients would achieve NSF LDL-C and TC targets with atorvastatin than with any of the other statins examined.

A pharmacoeconomic evaluation of the Myocardial Ischaemia Reduction with Aggressive Cholesterol Lowering (MIRACL) study in the United Kingdom.

OBJECTIVE: To determine the short-term healthcare costs associated with intensive lipid lowering with atorvastatin initiated within 24-96 hours of the occurrence of acute coronary syndrome (ACS) in patients in the UK. METHODS: Patient-level clinical outcome data from the Myocardial Ischaemia Reduction with Aggressive Cholesterol Lowering (MIRACL) trial and standard cost data were used to compare the total expected 16-week cost per patient on atorvastatin 80 mg/day versus placebo. Clinical outcomes assessed included the following: death; cardiac arrest with resuscitation; nonfatal myocardial infarction; worsening angina pectoris with objective evidence of myocardial ischaemia requiring rehospitalisation; surgical or percutaneous coronary revascularisation; nonfatal stroke; hospitalisation for angina without objective evidence of myocardial ischaemia; and new or worsening congestive heart failure requiring rehospitalisation. All relevant direct medical costs from the perspective of the NHS were considered. RESULTS: The total expected cost was pound 784.05 per patient in the placebo cohort and pound 851.59 per patient in the atorvastatin cohort, resulting in an incremental cost of pound 67.54 per patient in the atorvastatin group. The cost per event avoided was pound 1762.04. A third of the cost of atorvastatin treatment was offset within 16 weeks by the cost savings resulting from the reduction in the number of events in the atorvastatin cohort compared with the placebo cohort. CONCLUSION: The clinical benefits of short-term intensive atorvastatin treatment administered after ACS is attainable through a marginal increase in 'upfront' costs.

Regulation, competition and network evolution in aviation.

Our focus is the evolution of business strategies and network structure decisions in the commercial passenger aviation industry. The paper reviews the growth of hub-and-spoke networks as the dominant business model following deregulation in the latter part of the 20th century, followed by the emergence of value-based airlines as a global phenomenon at the end of the century. The paper highlights the link between airline business strategies and network structures, and examines the resulting competition between divergent network structure business models. In this context we discuss issues of market structure stability and the role played by competition policy.