New and emerging technologies, such as transdermal patches and needle-free-injection devices – discussed on page 22 of this magazine – certainly have a role to play in the drug delivery field, but we must remember that there are limitations caused by the biochemical properties of many therapeutic drugs. For instance, patch technology today is routinely used with lipophilic drugs that require relatively small volumes of the active substance to enter the bloodstream via diffusion. The number of drugs that can be put incorporated into these technologies – and consequently the medical indications that can be addressed with them – are quite limited at the moment. In my view, the biggest trend impacting drug delivery is the explosive growth in complex compounds, particularly biologic drugs. And many of these new drugs are best suited for administration via a traditional injection. Needle-based injection systems have been used for decades – and although many people do not like needles, they are certainly effective where larger volumes of an active drug substance need to be delivered – either subcutaneously or intramuscularly. Non-lipophilic drugs, like many antibodies and peptides for example, are used with a large volume of drug solution. They are often needed in high concentrations and can be quite viscous, which makes their administration via non-needle-injection highly challenging. One popular format for injectable drug delivery is the prefilled syringe. In the short term, prefilled syringes provide the clinical benefit of reducing the number of steps in the administration process, which, in turn, reduces the risk of dosing error. Whenever you use a separate syringe and vial you must first extract the dose from the vial into the syringe – and it’s difficult to be 100 percent accurate with this manual process. Over time you run the risk of imprecise dosing and wastage of API since vials tend to be slightly overfilled since it is impossible to extract all of the content from a vial.
Biopharmaceutical compounds are often very delicate and tend to be unstable, leading to limited shelf life. Injection technology has needed to advance to meet the needs of these important medicines. One way of dealing with shelf-life limited drugs is the process of lyophilization. Applying this approach in dual-chamber technology, the drug ingredient and solvent can be kept separate within the injection device and then easily mixed and administered just prior to administration. A key advantage to these ‘all-in-one’ solutions is the reduction in the risk of needle stick injuries. If you have the drug and the solvent in two vials, you first have to decant the contents of the solvent vial into the syringe, then put the syringe with its solvent into the API vial, and then mix before extracting the combined drug from the vial. There are a lot of steps in this process, which creates a greater risk of needle injuries. All in one solutions are easy to use and also allow for non-professionals, such as patients and family members, to safely use the devices. This trend is crucial given the growth in chronic diseases, such as diabetes and multiple sclerosis, and the fact that many patients want the option of convenient and easy-to-use injection technology that they can administer at home, such as pens and autoinjectors. Integrating electronically supported device technology here might also contribute to higher patient compliance and consistency. Injection devices should always be designed with safety and simplicity in mind. One of our innovations consists of a needle hub and a needle shield, which is partly produced by means of a two-component injection modeling process of polypropylene and thermoplastic elastomer. We’ve also added a tamper-evident closure system, combined with an integrated staked needle that supports the product integrity of the system. Little touches like this can make a real difference to patient safety. I believe that injectable drugs will continue to be a dominant method of drug delivery for years to come. This is supported by 2014 figures from IMS Health data for the global injectable drug market, which show an impressive sales value of $290 billion US or, in sales units, a volume of 42 billion units. Additionally, the number of novel new drug approvals increased from 13 injectables in 2010 to 19 in 2014. Having a detailed look at the prefilled syringe sector, according to a Visiongain world market outlook until 2024, the prefilled syringe market size will constantly increase unit-wise from 3.52 billion in 2014 to 6.93 billion in 2024, which means a cumulated annual growth rate (CAGR) of around 6 percent. The increase is also attributed to the growth in the demand for chronic disease treatment and cancer. The development of new and ever-increasingly complex drug products is a fascinating challenge for all of us in the drug manufacturing industry. There will always be a need to develop new packaging and delivery formats that meet or exceed the required standards of these drugs. And at the same time, there is the human element to the business. We must always be mindful of the patients and what they expert and need from their medicines and the drug delivery method.
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