Conventional filling techniques in the pharmaceutical industry often see semi-solid and viscous products such as ointments, gels, and creams applied via a dosing syringe. However, the quantities required for dosing are decreasing and accuracy when filling the dosing syringe is becoming more important.
Dosing syringes are used for the precise application of highly effective substances. By pressing down on the plunger, the user can dose the product more accurately and easily. Conventional filling technologies used in the pharmaceutical industry are reaching their limits when it comes to the highly accurate filling of viscous or paste-like products into syringes.
Viscotec offers the optimal solution. The ointment is fed into the dispenser using a pressurised cartridge and the syringe is attached to the pump outlet using an adapter. The filling process is then started by the operator pressing the start button on the HMI panel or alternatively by a foot switch. Once filling is complete, the operator removes the syringe and closes it with a cap. The syringe is filled through a cone, which allows for bubble-free filling.
In such filling processes, high pressure can form due to the viscosity of the medium and the small opening, but this is managed by Viscotec’s endless piston technology. A small amount of the medium is then withdrawn from the cone in order to keep it clean.
For this part of the filling process, the direction of the rotation is changed so that the ointment can be accurately retracted back into the filling needle. This retraction function can also be applied to media whose threads do not break easily. Volume, velocity and acceleration can be individually adjusted depending on the requirements of the product. As a result of the defined breakage of the threads, an extremely precise filling process is carried out.
The Free University of Berlin DendroPharm GmbH carried out clinical trials for the filling of high viscous thixotropic ointment. Trials to determine filling ability and optimal filling parameters of ointment were jointly carried out at ViscoTec’s testing plant.
It was aimed for 10,000 dispensing syringes to meet GMP standards when filled, with 1ml of waterless ointment (with an approximate dynamic viscosity of 160,000mPas). It was to be free from air bubbles and have a tolerance of +/- 1%. Multi-dose dispensing syringe were tested and a single dose was less than 5µl.
The ointment was produced in 20kg batches, with minimal product wastage. The filling process was semi-automatic and carried out in a user-friendly and reliable manner. The technology used was validated by the pharmaceutical industry and met appropriate cleaning requirements, using FDA compliant materials.
These filling trials achieved a filling tolerance of under +/-0,5%, as well as a very good repeat accuracy. For the 40 fillings, the dosing of 1ml fell within a range of 0,996ml to 1,004ml, with a probability of 99,7% (3 times standard deviation).
Due to the manageable size of the Pharma Dispenser system, it can be stored in a cupboard until it is required, saving space. When setting up the filling system all that is required is a 230V connection for the controls, a compressed air connection with pressure regulator for the cartridge, and a holder for the dispenser. Due to the modularity of the system, it can be easily adapted with little effort for the many applications.
DendroPharm is supported by dispensing specialists from ViscoTec and extensive commissioning documentation. Like all of ViscoTec’s dosing pumps, the Pharma Dispenser is based upon its endless piston technology. This includes a rotating positive displacement pump and eccentric screw technology. In this way, the stainless steel rotor moves eccentrically in a stator made from elastomer. Through the interaction of rotor and stator, chambers are formed.
The size of the alternately opening chambers remains constant during the rotation, so there is no compression of the product. This geometry allows for a precise, gentle and pulsation-free product flow. In addition to liquid media, high viscous creams, gels or pastes (<500.000mPas) can also be supported for perfect pulsation-free filling.
This shear-sensitive technology is also well suited for biotechnological products, products with solids such as suspensions or medicines containing crystals.
The Pharma Dispenser is a smart solution for the precise, semi-automatic filling of semisolid pharmaceutical products and can be used for production at any time. It excels in providing a clean, gentle and highly precise dosing, covering liquids to high-viscous media.
About DendroPharm
DendroPharm, which was established in 2013, has developed nanocarrier systems based on dendritic biodegradable polyglycerols. These amphiphilic carrier systems enhance the penetration of both lipophilic and hydrophilic active agents into the skin or into tumour tissue. The company offers customised nanocarriers syntheses.