Influence of acute upper respiratory tract infection on the absorption of inhaled insulin using the AERx insulin Diabetes Management System

Impact of symptomatic upper respiratory tract infections on insulin absorption and action of Technosphere inhaled insulin

OBJECTIVE

Uncomplicated, acute upper respiratory tract infections (URTIs) occur in patients with diabetes at a similar frequency to the general population. This study (NCT00642681) investigated the effect of URTIs on the pharmacokinetic (PK) and pharmacodynamic (PD) properties of Technosphere inhaled insulin (TI) in patients with type 1 or type 2 diabetes.

RESEARCH DESIGN AND METHODS

This was a phase 2 study conducted in patients who developed a URTI while being treated with TI in a phase 3 study (N=20, mean age 50 years, 60% men). Patients underwent two 4-hour meal challenges, during which blood samples were drawn to measure serum fumaryl diketopiperazine (FDKP; the excipient representing an essential part of TI), serum insulin, serum C-peptide, and plasma glucose. The primary outcome was the ratio of serum FDKP area under the concentration-time curve from 0 to 240 min (AUC0-240 min) during URTI and after clinical resolution of URTI symptoms (≥15 to ≤45 days).

RESULTS

No significant differences in PK parameters were seen during URTI versus post-URTI for FDKP. The ratio of serum FDKP AUC0-240 min during URTI and post-URTI was 1.1 (SD 0.6), p=0.4462. Plasma glucose concentrations during each 4-hour meal challenge were similar, showing small non-significant differences. No adverse events, including hypoglycemia, occurred during meal challenge visits.

CONCLUSIONS

Development of an active, symptomatic URTI during treatment with TI had no significant impact on the PK/PD properties of TI, suggesting that no adjustment in prandial insulin dosing is needed. However, if patients are unable to conduct proper inhalation, they should administer their prandial insulin subcutaneously.

TRIAL REGISTRATION NUMBER

NCT00642681; Results.

Inhaled insulin: a breath of fresh air? A review of inhaled insulin

PURPOSE

Despite many advances in diabetes care over the last century, some elements of insulin therapy remain inadequate for optimal care of the patient with diabetes. There is a need for improved pharmacokinetics and pharmacodynamics of rapid-acting insulin analogues to mimic physiologic insulin secretion. In addition, a major barrier to successful insulin therapy has been patient resistance. Alternative routes of insulin administration, including inhaled insulin, have been under investigation for several years. This review discusses the rationale for pulmonary delivery of insulin, compares previous inhaled insulin products, reviews the literature on the safety and efficacy of a current inhaled insulin formulation under investigation, and compares this product with other prandial insulin products.

METHODS

English-language studies and reviews of inhaled insulin were searched in MEDLINE, the ClinicalTrials.gov registry (through May 2014), and the US Food and Drug Administration Website.

FINDINGS

Inhaled insulin has several favorable characteristics due to pulmonary anatomy/physiology and the lack of injections. Pharmacokinetic and pharmacodynamic studies have shown a time-action profile suitable for prandial insulin use. Inhaled insulin seems to be safe and effective compared with other prandial insulin products and may be preferable to subcutaneous rapid-acting insulin analogues in terms of time-action profiles and rates of hypoglycemia. Small decreases in forced expiratory volume in 1 second (FEV1) have been shown with inhaled insulin, although this finding is not progressive over time and reverses with cessation of the medication.

IMPLICATIONS

Although several inhaled insulin products have been under investigation, only one (Exubera(®) [Nektar Therapeutics, San Carlos, California/Pfizer Inc, New York, New York]) was approved by the US Food and Drug Administration, and it was pulled from the market after only a short period of time. Technosphere(®) insulin (MannKind Corporation, Valencia, California) is currently the only inhaled insulin that remains under investigation. A review of the past and present literature on inhaled insulin is pertinent in understanding the current status of inhaled insulin and its risks and benefits. The current literature suggests that inhaled insulin could be a valuable option for prandial insulin administration, with a favorable risk to benefit ratio in some patients.

Further experimentation of inhaled; LANTUS, ACTRAPID and HUMULIN with todays' production systems

BACKGROUND

Several aerosol production systems have been used for aerosol insulin production. However; since the first studies several new models of jet-nebulizers and ultrasound nebulizers have been introduced in the market.

MATERIALS AND METHODS

Three different models of jet-nebulizers (different brands, same properties) and three different ultrasound nebulizers (different brands, same properties). Six residual cups (2 small ≤ 6 ml and 3 large ≤ 8 ml) were used for the jet-nebulizers. The ultrasound nebulizers were used with their facemasks or with their inlets which were included in the purchase package.

RESULTS

Ultrasound nebulizers; LANTUS produces by far the lowest mean droplets (2.44) half the size of the other two drugs (4.43=4.97). GIMA nebulizer is the most efficient producing one third of the droplet size of SHIMED and one second of EASYNEB (2.06<3.15<6.62). Finally, the 4 ml loading concentration is more suitable for supporting the production of smaller droplets (3.65<4.24). Drugs and nebulizers act interactively yielding very large droplets when ACTRAPID and HUMULIN are administered in joint with SHIMED nebulizer (9.59=7.72). Jet-nebulizers; HUMULIN again is the least preferred insulin since it hardly reaches the low but equal performance of others at the loading level of 6 ml. Residual cups E and B produce uniquely lower mean droplets at loading level 6.

CONCLUSIONS

Ultrasound nebulizers; the best suggested combination should be LANTUS insulin, GIMA nebulizer administered at loading dose of 4 ml jet-nebulizers. A global review can give the best combination: the lowest mean droplets are produced when the drugs LANTUS (mostly) and ACTRAPID are administered, applying the SUNMIST nebulizer in concert with residual cup B at loading levels of 6 ml.

Can inhaled insulin be used for the treatment of diabetes mellitus?

Reluctance to start and adequately titrate subcutaneous insulin are major reasons why many patients with diabetes mellitus are insufficiently metabolically controlled. Pulmonary insulin administration has the advantage over subcutaneous insulin in that it is noninvasive, seems better accepted by the diabetic population and exerts equal efficacy in terms of glycemic control. As such, inhaled insulin has the potential to increase the diabetic (Type 2) patient's willingness to commence and adhere to insulin therapy. Inhaled insulin's short duration of action makes it suitable for prandial administration provided that basal insulin requirements are met by residual b-cell function, or by supplemental long-acting subcutaneous insulin. In clinical trials, inhaled insulin is comparable to short-acting subcutaneous insulin with regard to efficacy and hypoglycemic risk. Adverse effects associated with inhaled insulin include dry cough, which tends to diminish over time, a slight drop in pulmonary function that does not progress and is reversible in most patients if treatment is discontinued, and increased insulin antibody formation, albeit without clinical sequelae. Long-term safety remains an issue for a product intended to be used chronically for many years. Exubera((R)) was thus far the only inhaled insulin product to receive approval in the USA and Europe for use in adults with Type 1 or Type 2 diabetes, but was recently withdrawn from the market. At present it is unclear how this decision will affect programs from other companies with inhaled insulin products under development.

Novel hormonal delivery method using the ink-jet technology: application to pulmonary insulin therapies

BACKGROUND

A device developed based on ink-jet printer technology can precisely control the size and volume of droplets ejected. Here, we evaluated the application of this technology to the pulmonary administration of insulin mist as a therapeutic measure for diabetes.

METHODS

Insulin ejected from the ink-jet device was initially characterized by high-performance liquid chromatography (HPLC) and mass spectrometry. Its effects on D-glucose uptake rate by L6 cells were then investigated. Next, different insulin solutions (with or without additives or ink-jet processing) were subcutaneously administered, and their pharmacodynamic features were evaluated. Finally, decreases in plasma glucose level in rats were examined after ventilator-assisted pulmonary administration of insulin mist.

RESULTS

Neither the HPLC nor the mass spectrometry profile of insulin was altered by the ink-jet process. The D-glucose uptake rate by L6 cells that received the recovered aerosolized insulin solution was similar to that of cells treated with control insulin, at 107%. Neither the addition of additives nor the ink-jet process used for insulin aerosolization impaired the plasma glucose-lowering action of subcutaneously injected insulin. Similarly, the efficacy of pulmonary insulin administration was not affected by the additives or the ink-jet process. Plasma glucose levels showed a trend towards decreasing after ventilator-assisted pulmonary administration of insulin mist. Plasma insulin level increased 30 min after the inhalation.

CONCLUSIONS

The ink-jet process did not affect the quality or biological activity of insulin, suggesting the potential use of the ink-jet device for insulin inhalation therapy for diabetes.

Inhaled insulin: overview of a novel route of insulin administration

Diabetes is a chronic disease characterized by inadequate insulin secretion with resulting hyperglycemia. Diabetes complications include both microvascular and macrovascular disease, both of which are affected by optimal diabetes control. Many individuals with diabetes rely on subcutaneous insulin administration by injection or continuous infusion to control glucose levels. Novel routes of insulin administration are an area of interest in the diabetes field, given that insulin injection therapy is burdensome for many patients. This review will discuss pulmonary delivery of insulin via inhalation. The safety of inhaled insulin as well as the efficacy in comparison to subcutaneous insulin in the various populations with diabetes are covered. In addition, the experience and pitfalls that face the development and marketing of inhaled insulin are discussed.

Current challenges in non-invasive insulin delivery systems: a comparative review

The quest to eliminate the needle from insulin delivery and to replace it with non- or less-invasive alternative routes has driven rigorous pharmaceutical research to replace the injectable forms of insulin. Recently, various approaches have been studied involving many strategies using various technologies that have shown success in delivering insulin, which are designed to overcome the inherent barriers for insulin uptake across the gastrointestinal tract, mucosal membranes and skin. This review examines some of the many attempts made to develop alternative, more convenient routes for insulin delivery to avoid existing long-term dependence on multiple subcutaneous injections and to improve the pharmacodynamic properties of insulin. In addition, this article concentrates on the successes in this new millennium in developing potential non-invasive technologies and devices, and on major new milestones in modern insulin delivery for the effective treatment of diabetes.

Inhaled insulin

Inhaled insulin has attractive pharmacodynamic properties with a fast onset of action which should lead to improved postprandial blood glucose concentrations. Comparisons with regular subcutaneous (sc) insulin in clinical studies, however, showed lower fasting blood glucose concentrations. Overall, clinical efficacy of inhaled insulin was comparable to that of regular sc insulin. Treatment with inhaled insulin was safe and well tolerated, with slight and reversible changes in lung function parameters and a rise in insulin antibodies (not associated with any clinical or safety parameters) as main adverse effects. Treatment satisfaction in open-label studies was higher with inhaled than with sc insulin, indicating that inhaled insulin might help to overcome one of the major hurdles of diabetes therapy, i.e. a timely initiation of insulin therapy. The first inhaled insulin formulation was approved in the US and Europe in January 2006, but some countries granted reimbursement only for selected patients, or did not reimburse treatment with inhaled insulin at all because of the high treatment costs. These are due to the rather low bioavailability of approximately 8-15%. Therefore, further research is needed to improve the bioavailability of inhaled insulin: e.g. through optimization of the inhaler, the insulin formulation, or the inhalation technique. In view of the potential for further improvement, inhaled insulin may become a very attractive alternative to sc insulin, in particular in patients in whom insulin therapy has to be initiated and/or intensified.

Inhaled insulin using AERx insulin Diabetes Management System (AERx iDMS)

Diabetes is a chronic, debilitating disease that afflicts millions of people worldwide and poor glycemic control in this disease leads to numerous microvascular and macrovascular complications. There is growing evidence that tight glycemic control prevents the development, and delays the progression, of microvascular complications and possibly macrovascular disease in patients with diabetes. All patients with Type 1 diabetes and many patients with Type 2 diabetes require intensive insulin therapy to achieve optimal glucose control. Although subcutaneous insulin therapy is the mainstay of insulin therapy, there are patients who fear needles and often refuse to start insulin therapy despite suboptimal glucose control. In these patients, inhaled insulin represents a non-invasive, painless method to administer intensive insulin treatment. The Novo Nordisk AS AERx iDMS (insulin Diabetes Management System) for inhaled insulin is a novel device that administers an aerosol of liquid insulin into the deep lung with dose adjustments as precise as one subcutaneous unit. Initial pharmacokinetic and pharmacodynamic studies demonstrate that the device delivers liquid insulin in a clear dose-response manner and with a rapid onset of action similar to the fast-acting analog insulins. At present, large, long-term Phase III studies are in progress to document not only the efficacy, but also the safety and feasibility of this device in the treatment of patients with diabetes.

The effect of exercise on the absorption of inhaled human insulin via the AERx insulin diabetes management system in people with type 1 diabetes

OBJECTIVE

This study investigated the effect of moderate exercise on the absorption of inhaled insulin via the AERx insulin diabetes management system (iDMS).

RESEARCH DESIGN AND METHODS

In this randomized, open-label, four-period, crossover, glucose clamp study 23 nonsmoking subjects with type 1 diabetes received a dose of 0.19 units/kg inhaled human insulin followed in random order by either 1) no exercise (NOEX group) or 30 min exercise starting, 2) 30 min after dosing (EX30), 3) 120 min after dosing (EX120), or 4) 240 min after dosing (EX240).

RESULTS

Exercise changed the shape of the free plasma insulin curves, but compared with the NOEX group the area under the curve for free plasma insulin (AUC(ins)) for the first 2 h after the start of exercise was unchanged for EX30 and EX240, while it was 15% decreased for EX120 (P < 0.01). The overall insulin absorption during 6 and 10 h after dosing was 13% decreased for EX30 (P < 0.005), 11% decreased for EX120 (P < 0.01), and unchanged for EX240. Exercise did not influence the maximum insulin concentration (Cmax), while the time to Cmax was 22 min earlier for EX30 (P = 0.04). The AUC for the glucose infusion rate (AUC(GIR)) for 2 h after the start of exercise increased by 58% for EX30, 45% for EX120, and 71% for EX240 (all P < 0.02) compared with the NOEX group.

CONCLUSIONS

Thirty minutes of moderate exercise led to unchanged or decreased absorption of inhaled insulin via AERx iDMS and faster Cmax for early exercise. Thus, patients using AERx iDMS can adjust insulin dose as usual independent of time of exercise, but they should be aware of the faster effect if exercising early after dosing.

Selection and education of patients for inhaled insulin

Inhaled insulin is a recent advance in insulin delivery that promises to be an effective alternative to subcutaneous insulin. Several insulin delivery systems are currently in development and the first of these has been approved for clinical use. Inhaled insulin offers greater flexibility and convenience for patients with diabetes and may be particularly useful in those who are reluctant to initiate or intensify insulin treatment. Although promising, potential concerns remain regarding its long-term effects on lungs. Also, excluding certain groups of patients such as smokers and those with respiratory illnesses will restrict its use at present. Lack of familiarity with the technology, especially relating to dose adjustments and inhaler device, is also likely to present fresh challenges. But, careful selection of patients, education, and continued support from health professionals is vital to ensure success with this new technology.

Peptide Drug Delivery Strategies for the Treatment of Diabetes

Drug delivery strategies for diabetes have included a wide range of scientific and engineering approaches, including molecular design, formulation and device design. Molecular engineering has resulted in modified pharmacokinetics, such as rapid-acting or slow-release analogs of insulin. Long-acting insulin formulations are designed to meet the body's basal needs, whereas rapid-acting insulin formulations are designed to cover mealtime glucose spikes. Furthermore, the discovery of new therapeutic biomolecules, which like insulin need to be injected, will drive the need for more flexible and universally applicable delivery systems. Formulation design, such as particle engineering, can be used to modify pharmacokinetic profiles. In general, suspension formulations of insulin commonly demonstrate reduced solubility and result in sustained release. Similarly, depot injections can result in precipitation of insulin at the site of injection, again resulting in lower solubility and sustained release. Particle engineering also has been applied to pulmonary formulations for delivery to the deep lung. The creation of novel drug delivery methods for the treatment of diabetes should remove barriers to insulin therapy and increase patient acceptance and compliance. Eliminating routine injections with needle-free injectors, insulin pumps, inhalation, buccal sprays, intra-nasal delivery, and transdermal patches may offer increasingly attractive alternatives.

Effect of upper respiratory tract infection on AIR inhaled insulin pharmacokinetics and glucodynamics in healthy subjects

The suitability of employing AIR Inhaled Insulin (AIR Insulin; AIR is a registered trademark of Alkermes) during acute upper respiratory tract infection (URI) has not been determined. Twenty-one healthy, non-diabetic subjects were enrolled in a single-sequence, two-period, euglycemic clamp study. Subjects received a single 12 U-equivalent dose of AIR Insulin before rhinovirus (RV16) inoculation and during symptomatic infection. Spirometry was used to evaluate pulmonary safety. AIR Insulin exposure (the area under the immunoreactive insulin (IRI) concentration vs time curve from time zero until the IRI concentrations returned to the predose baseline value (AUC(0-t'))) and glucodynamic response (total amount of glucose infused (G(tot))) were comparable before and during RV infection (AUC(0-t') 46,300 vs 52,600 pmol min/l, P=0.21; G(tot) 61,800 vs 68,700 mg, P=0.42, respectively). Variability of pharmacokinetic and pharmacodynamic parameters did not change during URI; either did the number or intensity of adverse events. No significant change in forced expiratory volume or forced vital capacity was observed following AIR Insulin administration or during URI. The AIR Insulin system provides similar pharmacokinetic and glucodynamic responses under conditions of an experimentally induced RV infection and is regarded as suitable for use in diabetic patients during URIs.

Delivering needle-free insulin using AERx iDMS (insulin diabetes management system) technology

BACKGROUND AND METHODS

Inhaled insulin has recently emerged as an alternative to subcutaneous insulin administration. One inhaled insulin device, AERx (a registered trademark of Aradigm Corp., Hayward, CA, or its affiliates in the United States and other countries) insulin diabetes management system (iDMS) (Novo Nordisk A/S, Bagsvaerd, Denmark), uses a unique liquid human insulin strip to deliver an aerosol of insulin to the lungs. AERx iDMS enables 1-unit increment dosing, and the device ensures that the insulin dose is released at the optimal point of inhalation for delivery to the lungs.

RESULTS

Compared with subcutaneous human insulin, the pharmacokinetic and pharmacodynamic profile of inhaled insulin with AERx iDMS is similar, but with a more rapid onset of action. Data from these pharmacokinetic studies have also demonstrated that inhaled insulin dosing with AERx iDMS is as consistent and reproducible as subcutaneous human insulin.

CONCLUSIONS

In individuals with diabetes, prandial inhaled insulin with AERx iDMS is as effective and well tolerated as subcutaneous prandial human insulin or insulin aspart in terms of glycemic control and overall hypoglycemia. No major safety concerns have been raised with respect to pulmonary function tests. Other clinical studies using AERx iDMS in special populations, such as smokers, people with asthma, or people suffering from upper respiratory tract infections, have provided important information regarding the use of inhaled insulin in these circumstances. Overall, pulmonary insulin delivery with the AERx iDMS device appears to be a promising safe and efficacious alternative to subcutaneous insulin injections.

First approved inhaled insulin therapy for diabetes mellitus

The long-term benefits of tight glycemic control in preventing microvascular and macrovascular complications are well established in both Type 1 diabetes mellitus (Type 1 DM) and Type 2 diabetes mellitus (Type 2 DM). Nonetheless, achievement of recommended haemoglobin A1c (HbA(1c)) goals (< or = 6.5 - 7.0%) has remained elusive, especially in patients with diabetes who require insulin therapy. Delayed/suboptimal titration of insulin is partly related to poor acceptance of multiple injection regimen by both physicians and patients. EXUBERA (human insulin [rDNA origin]; Pfizer), the first approved inhaled insulin for the treatment of diabetic patients, has been shown to be safe and as effective as regular/rapidly acting insulin in improving glycemic control. In addition to controlling postprandial glucose excursions, EXUBERA exerts a major action to reduce fasting plasma glucose (FPG) concentration. Thus, it has the potential to be used as a monotherapy in Type 2 DM, as well as in combination with an insulin sensitizer in Type 2 DM or in combination with long-acting insulin in both Type 2 DM and Type 1 DM.

Inhaled insulin (Exubera): Combining efficacy and convenience

The pulmonary route, due to its rich vascularity, large surface area and immunotolerant characteristics, may be an ideal target for drug delivery. Although the inhaled route has been used to deliver drugs used in the management of respiratory disorders, success with peptide delivery has been limited by poor bioavailability. Recent advances in technology have overcome these barriers and have enabled new delivery devices to be developed. Insulin is the first peptide to be delivered successfully by this route and the first of the inhaled insulin delivery devices (Exubera) has now been approved for clinical use. In clinical trials it has been shown to be effective, apparently safe and a preferred alternative to subcutaneously injected meal-time insulin. This new technology offers great convenience to patients needing insulin treatment. While it will considerably reduce the number of injections needed by people with type 1 and type 2 diabetes, it should also encourage more patients to start insulin treatment earlier. The potential benefits from improved adherence and better glycaemic control with this insulin are also significant.

Alternatives routes of insulin delivery

Optimal glycaemic control is necessary to prevent diabetes-related complications. An intensive treatment, which could mimic physiological insulin secretion, would be the best one. However subcutaneous insulin treatment is not physiologic and represents a heavy burden for patients with type 1 and type 2 diabetes mellitus. Consequently, more acceptable, at least as effective, alternative routes of insulin delivery have been developed over the past years. Up to now, only pulmonary administration of insulin (inhaled insulin) has become a feasible alternative to cover mealtime insulin requirements and one of the various administration systems was recently approved for clinical use in Europe and the United States. But, due to advances in technology, other routes, such as transdermal or oral (buccal and intestinal) insulin administration, could become feasible in a near future, and they could be combined together to offer non-invasive, efficacious and more physiological way of insulin administration to patients with diabetes.

Inhaled cytokines and cytokine antagonists

Cytokine and cytokine antagonist have provided novel and effective therapies for many human diseases. A number of approved cytokines including the interferons (alpha, beta and gamma), interleukin-2 (IL-2), granulocyte macrophage colony stimulating factor (GM-CSF) as well as novel cytokine antagonists have been administered by the pulmonary route for both local lung disease and as a non-invasive method for systemic delivery. We review the published clinical experience of inhaled cytokines and cytokine antagonists. We discuss the limitations of the existing data and the type of clinical data desired to establish the advantages and safety of inhaled cytokines and cytokine antagonists.

Clinical evaluation of inhaled insulin

Diabetes affects over 18.2 million individuals in the United States alone. Current therapy to treat type 1 diabetes relies on subcutaneous insulin administration either by injection or continuous infusion. In addition, patients with type 2 diabetes who fail lifestyle intervention and oral therapy require subcutaneous insulin. Optimal injection protocols to achieve tight metabolic control often prove burdensome to patients. Thus, development of pulmonary insulin delivery to supplement and/or replace subcutaneous insulin injections may be an effective alternative, allowing patients to achieve intensive diabetes management. This review will discuss the devices in development for the delivery of inhaled insulin. In addition, the efficacy of inhaled insulin in both type 1 and type 2 diabetic populations will be discussed. Finally, the available safety data with respect to the unique pulmonary effects of inhaled insulin will be covered.

Non-invasive routes for insulin administration: current state and perspectives

Diabetes mellitus is a chronic disease that usually requires multiple insulin injections to achieve adequate glycaemic control. This represents a major cause of reduced compliance to treatment. Consequently, other routes for insulin administration have been explored. During recent years, much progress in the development of inhaled insulin has been made. Inhaled insulin has shown favourable properties, such as a rapid onset of action, improved bioavailability and good tolerability; thereby providing satisfaction and ease of administration. However, long-term safety of inhaled insulin needs to be assessed, and the cost would be higher than injectable insulin. Nasal, oral and transdermal insulins are undergoing early phases of pharmacological development. The purpose of this review is to describe the latest developments in the area of non-invasive routes for insulin delivery.

Inhaled insulin: new technology, new possibilities

The prevalence of diabetes is reaching epidemic proportions with an increasing need for new therapies. Several new therapies are in development and amongst these is inhaled insulin. Inhaled insulin is a novel way of delivering insulin and has been shown to have an efficacy comparable to subcutaneous insulin in patients with both type 1 and type 2 diabetes. Several inhaled insulin delivery systems are currently in development and the first of these, Exubera has recently been granted license in Europe and in the USA. In this article we review the efficacy and safety profile of Exubera and discuss its potential place in the management of diabetes.

Regimen and device compliance: key factors in determining therapeutic outcomes

The two most important differences between inhaled and oral therapy are (1) the lungs have evolved to exclude foreign material while the gut has evolved to take in large amounts of foreign material, and (2) even if patients adhere to a treatment regimen (regimen compliance or adherence), they may fail to derive any benefit from using an inhaler due to failure of drug delivery (poor device compliance). In other words: True compliance = regimen compliance x device compliance. Aerosol scientists, building on the observations of those working in the field of industrial hygiene, have developed devices that largely address the challenge of bypassing the lung's defenses, in that current devices generate aerosols that contain a significant proportion of particles in the range of 1-5 microm. These have a relatively high probability of entering the lungs and depositing through impaction and/or sedimentation. The development of delivery systems for systemically acting drugs has led to further refinement. The second issue, that of patient behavior, has, until very recently, received very little attention from those developing devices. Regimen compliance involves taking the medication at the suggested times. Device compliance (using the device optimally) is dependent on competence and contrivance. A patient taking a tablet before rather than after a meal is likely to receive some therapeutic benefit even if the effect is suboptimal. A patient whose device compliance is poor because either they are not competent to use the device or contrive to use it in an ineffective manner may derive little or no benefit even if they are scrupulously adhering to their treatment regimen. Lack of precision in the use of the terms "compliance" and "adherence" has contributed to the failure to build in features that may help address issues relating to patient behavior. The resurgence of interest in developing devices that can be used to deliver potent systemically acting drugs has, out of necessity, led to the development of systems that help minimize the impact of poor competence or contrivance on drug delivery. There are suggestions, that need to be confirmed, that regimen compliance (adherence) can be influenced by providing feedback. In the absence of formal studies, comparison of the high-tech and low-tech approaches to improving device compliance incorporated into novel devices might provide valuable insights into what aspects of feedback are important in the clinical setting.