The modular concept of the ERWEKA Dissolution Systems offers a wide range of possibilities for automation under very simple and cost-saving conditions not known until today.

Years of experience in automating dissolution-processes and knowledge of the different needs of users has enabled us to develop a new series of dissolution-systems, that will satisfy almost all requirements and will support your future changing requests. Now every system can be modified locally by adding one or more modules to meet your requirements.

For high flexibility in sample processing and analysis the Offline Dissolution System with the FRL 800 Autosampler has been developed. This system will give the ability to precisely collect samples, to replenish media and automatically dilute samples. For analysis in a spectralphotometer or in an HPLC unit the collected samples are manually taken from the fraction collector and passed over to the analyser.

The advantage of this method is that no costly analysing system is coupled to the dissolution system; the customer may use any analysis system already available in the laboratory. Optionally the Offline Dissolution System can be later on updated and connected to a UV-VIS spectralphotometer, software and PC for automatic sample analysis.

In contrast to the FRL 800 Auto Sampler, the more simple and cost favourable FRL 700 only offers collection of the samples from the test vessels to different racks. This solution was generated for customers preferring simple application, a low grade of automation and low investment costs.

The management of the complete offline system is performed by the Dissolution Tester (“i”-version) itself.

Especially for customers testing a high number of identical products a dual-offline-system has been developed. This system consists of two dissolution testers, one syringe pump and an FRL 800 Autosampler to allow collection of up to max. 12 sample intervals from each dissolution tester. The total system can be rinsed after each sample cycle to avoid polluting by the other tester. The possibility for replenishment of the samples taken from the test vessel and the dilution of the collected samples is still available. The time management of the test cycles is completely controlled by the dissolution tester. In case 24 sample cycles are required, the system can be configured within seconds for a standard offline system by decoupling one dissolution tester.

The basic module of your dissolution system is, beside the dissolution tester, the ERWEKA 8-channel syringe-pump SP 840. Long experience with tube and piston pumps has shown this method as the optimal solution for flexibility, long life-time and high precision dosing. With the SP 840 syringe pump the dosage accuracy can be cut down to ± 0.2 ml, independently from collected or diluted volume. The use of 8 standard Hamilton® -syringes allows a fast and easy replacement of the syringes if necessary.

ERWEKA has stopped using delicate magnetic valves and has used electrically switched ones. The higher power of the electric motor ensures perfect functioning of the valves under all conditions. In addition the use of special valves allowed the use of larger tubing, for better function with particle containing media.

The valves used in the SP 840 are 4-way valves, that highly increase the flexibility of the system. Firstly it is possible by using one pump only, to collect high precision samples and to dilute (max. 1:10) the samples automatically. Also fresh media can be added to a sample taken out of the test vessel. The high-precision dosage ensures a high-accuracy result of the analysis.

The sample collection- and processing system FRL 800 Auto Sampler in combination with a syringe-pump SP 840 offers the advantage of collecting samples, to dilute automatically and to add medium to the samples taken out of the test vessels and to transfer the collected and diluted sample to a UV-VIS spectralphotometer (if upgraded to an Off-/Online Dissolution System).

Two tanks are included in the FRL 800 Autosampler to provide both, media replenishment for the test vessel and dilution of the collected samples. There is no volume limitation as both tanks can be refilled automatically with integrated tube pumps from external containers provided by the customer. The tanks of the FRL 800 can easily be removed for cleaning.

High flexibility is also offered in the number of sample racks. To fulfil the demand for long-term tests, the number of sample collection intervals was increased to 24, by using 10 ml glass tubes and 1.2 ml and 4.0 ml HPLC vials. For greater volumes or high dilution 16 samples can be stored in 25 ml glass tubes.

The FRL 800 Autosampler offers the possibility to collect samples in closed HPLC vials (1.2 or 4.0 ml). ERWEKA use special “slotted” vial covers to prevent overpressure and inaccuracy of dosage resulting from overpressure.

The well thought out and accurately routed Teflon tubing systems of the FRL 700 and FRL 800 ensure short distances and low volumes in the tubes to minimize faulty analysis.

For user friendly and fast removing of the rack, it is mounted on a movable tray. The rack is pulled out with the tray and can be replaced by another rack. A safety switch off function is included to prevent misuse.

The dilution of the samples in the FRL 800 Autosampler is performed quickly and reliably with high precision. The syringe pump will collect the sample from the test vessel to the test tube or HPLC-Vial with an accuracy of better than ± 0.1 ml. The syringe pump will then take the required dilution liquid out of the supply container and inject it into the sample (accuracy ± 0.1ml). To achieve the best mixing of the samples and the dilution medium, the dilution liquid is injected with maximum pressure and a constant upward move of the injection needle. The maximum dilution ratio is 1:10.This will result in a maximum dilution of 1:100 in the UV-VIS photometer if 1mm cuvettes are used.

The regulations of the pharmacopoeias prescribe, that the volume in the test vessels must be constant during a complete test cycle. Only a deviation of ± 1% of the requested volume is allowed. Even evaporation during a test cycle will lead to a loss of media. Using the FRL 800 Autosampler will solve this issue. Immediately after taking the sample, the syringe pump will re-supplement from a storage container that is automatically refilled after every cycle (accuracy ± 0.1ml).

All tubing on the sampling station on the dissolution tester as well as the filling tubes in the fraction collector are made of high quality stainless steel. Optional titanium tubing is available for very aggressive media.

Filtration of the samples is performed on ERWEKA systems generally in the test vessels. This will ensure contrary to other systems, that no particles have access to the sample tubing and system tubing. All active substances are kept in the text vessel for release testing. Additional hydrodynamic activity in the media caused by the filters is almost eliminated as the sample tubes and filters are moved into the medium only for a very short period, to take the samples only.

Should filtration better than 1µm be required, the ERWEKA systems offer a double filtering feature, conceived by one filter directly on the sampling tube and an additional exchangeable syringe paper filter inline on the tubing.