Med-Tech Innovation Drug delivery
Figure 1:
Maintaining a safe and effective dose level
developing a pump system to deliver Levodopa, which is used to treat Parkinson’s disease. Currently, treatment requires patients to take pills many times per day, thus it is anticipated that the pump will simplify treatment. Whereas the above drug examples require continuous
delivery, there are other situations that require non- continuous or pulsatile delivery. These include the delivery of drugs to treat a variety of conditions including hypercholesterolemia, asthma and cancer.1
In many
cases, the optimal delivery time is tied in with the circadian rhythm – the biological oscillations that occur on a roughly 24-hour cycle in many organisms, including humans. Arguably, if this requires delivery of a drug at a fixed point in the day, this could be achieved by self- administration of a pill or injection – but the use of a pump or transdermal patch may simplify administration, for example at night time.
Figure 2: Artificial pancreatic diagram illustrates a pump technology
In both cases, for continuous and pulsatile delivery, the availability of reliable and proven delivery device technology may influence the development of new drug formulations because they open up possibilities to improve safety and efficacy that previously did not exist.
Closing the drug delivery loop The treatment of diabetes using insulin is challenging because it requires the patient to titrate their dose by making blood sugar measurements. It is, therefore, not surprising that pump technologies have been developed (Figure 2) to simplify the administration of insulin, including the Insulet OmniPod mentioned above. Currently, diabetic pumps require the patient to make a blood sugar measurement and then to programme the pump depending on the test results. However, closed- loop systems (often termed an artificial pancreas or artificial pancreas device system) are under development and are seen to offer a significant advantage in the treatment of the disease. These systems monitor blood glucose on a continuous basis and use this to control automatically the delivery of insulin to ensure glycaemic control (optimal blood sugar concentration) using an appropriate algorithm. The technology is well advanced and the US Food and Drug Administration has made a strong commitment to defining the “regulatory science” to support the approval of these systems, therefore, it is anticipated that these systems will enter the market within the next 10 years. Once proven in this market, it is probable that the technology could be redeployed in other therapeutic areas, using similar or possibly lower-cost pump technologies. The closed-loop control could be achieved by monitoring drug levels or some other analyte related to disease in the blood or subcutaneous layer using an appropriate (bio) chemical sensor. Or, alternatively, it could involve a physical measurement such as arrhythmia for cardiovascular disease or perhaps neurological signals for a central nervous system disorder. Closed-loop drug delivery systems have regulatory and technical challenges, but these do not seem insurmountable if there is a strong enough clinical need.
Towards the future In conclusion, there seem to be some significant opportunities for the development of new and novel device technologies in the field of controlled release, and for those of us working in device technology there is no need to fear that formulation technologists will be putting us out of business any time soon. Looking further out and away from diabetes where the opportunity is obvious and immediate, the future for closed-loop drug delivery systems looks exciting and may also provide some good opportunities for device and diagnostics companies to collaborate with the pharma industry to develop more effective combination products.
Reference
1. G.S. Sharma et al., “Recent Trends in Pulsatile Drug Delivery,” International Journal of Drug Delivery, 2, 200–212 (2010).
Iain Simpson is a drug delivery specialist at Cambridge Consultants, Science Park, Milton Road, Cambridge CB4 0DW, UK tel. +44 (0)1223 420 024
email:
Iain.Simpson@
cambridgeconsultants.com www.cambridgeconsultants.com
22 ¦ September/October 2014
www.med-techinnovation.com
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48