Dave Gray speaks to Pascale Farjas, global category manager for ear, nose and throat, and Benoît Guillard, senior design engineer, at drug delivery expert Nemera, to find out how to design a drug delivery device for optimum patient compliance.
DG: What are the design considerations to ensure a full dose is delivered for each actuation?
PF: First, we need to make sure the nasal spray pump delivers the dose with a full stroke regardless of patient age or how the patient uses Advancia. This is achieved via a user-independent feature: at the beginning of the pump stroke, a stiff point is felt making the patient apply the required force to perform the full stroke of the pump in one unique movement. This full stroke enables the full delivery of the content of the chamber dose, with high precision and consistency.
DG: What measures did you take to ensure regulatory compliance?
BG: Advancia PF is compliant with EP/USP standards, and with applicable regulation for nasal sprays which I will not detail here. We are currently finalising validation of sterility according to ISO 11137.
DG: What were the human factors engineering considerations in designing this product?
PF: Engineering considerations during Advancia development were based on our marketing brief. On the performance side, the unique selling point of Advancia is user-independence. On the design side, ergonomy and convenience were the key drivers of our engineers. For instance, the full overcap of the snap-on version is here to respond to a triple need: hygiene while protecting the actuator, nomadic use for transport in a bag or pocket, and no accidental actuation during transport.
DG: Tell us about the design of the mechanical closing tip
PF: The objective of such a closing tip is to avoid any contamination through the orifice and clogging of the tip. How does it work? Purely mechanically: at rest position, the tip seal is closed under a spring force. Tip seal opens during spray delivery as bulk pressure exceeds closing spring force. After dose expulsion bulk pressure reduces and tip seal is closed immediately.
DG: How does the design ensure better compliance?
BG: Better compliance is achieved through the different design features of Advancia PF. It relies on a new pump engine technology, with a user-independent feature. What does that mean for the patient? On a user-perspective, the patient feels like having the full dose delivered due to Advancia’s actuation profile. On the performance side, the dose is 100% delivered, with high precision and consistency through product life. No matter how the patient uses Advancia, he/she will have the full dose delivered each time.
The mechanical closing tip avoids evaporation & clogging issues, which ensures the patient to have a spray for each delivery.
The anti-actuation overcap avoids any accidental spray delivery when transported in a purse or a pocket. Moreover, its hygienic overcap protects the actuator from dust/ external environment, which reassures the patient and corresponds to the patient lifestyle for a nomadic use Hence the patient can transport its nasal spray very easily for using it during the day, all that increasing patient adherence.
DG: What is PureFlow technology?
BG: PureFlow Technology is a patented technology developed by Nemera, which consists of filtering air entry by permeation through a silicone membrane. Air ingress is then sterile, without having any filter.
DG: Why is it important to have no interaction between metal parts and formulation?
BG: Some drug formulations and/ or active ingredients can oxidize in contact with metallic parts. Hence the active ingredient could lose its therapeutic efficacy or even become toxic. Moreover, these oxidation reactions also alter and degrade these metallic parts, thus liberating toxic particles for the brain. Last but not least, some deterging agents can be used during the manufacturing process of metallic parts, with the possibility to migrate into the drug formulation. That’s why, in general but for some drugs in particular, it is recommended the fluid pathway is metallic-free.
DG: Why did you decide on a one-step assembly version?
PF: Snap-on is the standard today for preservative-free nasal pumps. In order to differentiate our product on the market, Advancia has a patented specific snap-on system, with a full overcap, allowing a one-step assembly during drug filling. This new feature is intended to facilitate device assembly onto different containers (plastic or glass). Indeed, the assembly force required to snap the Advancia system onto the bottle is very similar from one bottle to another, as opposed to standard snap-on systems where the bottle neck design can have a high impact on the assembly force profile.