Inserted Needle Depth

Improved Autoinjector Design:Demonstrating highly consistent performance achieved

through the integration of a cyclic olefin syringe

Susanna White, Oval Medical Technologies

Oval Medical has developed a novel Prefilled Primary DrugContainer (PDC) that resolves many known drugcompatibility and functionality issues associated with the useof traditional glass syringe and rubber plunger technologies(e.g. contamination, glass breakage, variable deliveryforces). The PDC’s reconfigurable geometry and mouldedexternal interface features facilitate improved autoinjectordesign resulting in smaller, more reliable products. Thesepromote improved user compliance and provide consistentresults for inserted needle depth, delivered volumes anddelivery times (addressing the issue of wetinjections). Additionally, devices can be configured toaccommodate larger volumes and higher viscosities thantraditional glass and rubber based technologies.

Manufacturing consistencyThe moulded container and the supportive downstreammanufacturing processes ensure that the needle length isachieved accurately and consistently when compared toconventional glass-based technologies.Low activation and tissue compression forceThe low activation force and the absence of a secondaryactivation button are designed for ease of use and are intendedto eliminate variability of injection depth. In contrast, two-stepsystems necessitate an initial skin compression load to prime thedevice followed by a secondary load applied through anactivation button to trigger delivery. Dependent upon thepatient’s technique and grip this secondary load may be isolatedfrom the skin or form a cumulative load in conjunction with theinitial load directly onto the injection site. The additional forcewill compress the soft tissue and increase the risk ofintramuscular injection.Consistent subcutaneous deliveryBlue dye has been injected into porcine fat to ensure injectionsform a bolus at the correct depth when activated into a fleshmedium. Observations provide confidence that needle depth andneedle insertion mechanisms are appropriate.

This poster presents performance data for the Sumalen Ovali 0.5ml / 0.6mg Sumatriptan autoinjector manufactured using acommercially representative process. Results demonstrate consistency of device performance when new (T=0), and followingartificial (up to 24 months) and real-time ageing. Results for inserted needle depth, delivered volume, and delivery time arediscussed in detail.

A User-Centric Design

• Promoting adherence through minimising the number ofuser steps.

• Incorporating a guessable and intuitive user interface• Offering an easy to hold form in a highly portable

package• To ensure that the technology introduces real benefits to

the patient, several user studies have been conducted.Common feedback from studies include;

• ‘Non intimidating or frightening’• ‘Quick and easy to use’• ‘Small and lightweight’• ‘A large drug inspection window’• ‘No separate activation button to press’• 49 of 54 patients (90%) preferred the Oval device over

two alternative subcutaneous autoinjectors.

A Modular Autoinjector

Delivery Time

Consistent and appropriate delivery times are essential to ensure an effective injection. Specifically, delivery times which aretoo long or very inconsistent increase the risk of premature removal whereby the patient only receives a partial delivery (awet injection).Testing has demonstrated that Oval’s cup seal and foil technology produces consistent delivery times that donot increase throughout product shelf life. Careful material selection ensures that stiction issues are avoided without theneed for additional silicone coating processes. In addition to in-air testing, in vitro testing (porcine belly fat) is also performedto ensure back pressure does not result in inconsistent / extended delivery times or stalling. Results indicate that although theSumalen Ovali has a slower delivery time into air (~1.8 vs ~1.3s), it can better manage the back pressure of an in-flesh

The technology platform offers a range of device options thatcan be customised to accommodate different needle gauges,fill volumes and viscosities, whilst accurately meetingspecified target needle depths and delivery times.

1. Remove cap 2. Activate 3. Dispose

Oval’s autoinjector for subcutaneous injection is designed around the needs of the user and is not restricted by an existingglass-based PDC technology. The new moulded PDC facilitates the development of smaller devices that improve the userexperience by;

Delivered

Volume

Deliveredvolume datademonstratesaccuracy andconsistency atT=0 and overtime.

injection when compared to the reference product. The Sumalen Ovaliachieves superior consistency in all flesh samples whereas thereference product has longer delivery times and is more sensitive toanatomical variation. To further improve patient compliance, theSumalen Ovali includes audible feedback to indicate the start and endof drug delivery. This places less reliance on the patient counting to adefined time prior to removal from the injection site and helps toprevent wet injection.

Process DataLSLTargetUSLSample MeanSample NStDev (Within)StDev (Overall)

1*31.9264500.1203140.124405

Process Data

LSLTargetUSLSample MeanSample NStDev (Within)StDev (Overall)

0.483*0.5330.500604500.003763280.00435786

Oval Medical Technologies The Innovation Centre, Unit 23 Cambridge Science Park, Cambridge UK CB4 0EY www.ovalmedical.com