When it comes to the mechanical validation of dissolution testers, I believe friends engaged in the production and research of oral solid formulations are no strangers.
As of today, the process of mechanical validation for dissolution testers has evolved from being solely conducted by manufacturers on-site to being verifiable by third-party inspection agencies. It has transitioned from “outsourced validation” to “self-validation.” Simultaneously, the mechanical validation toolkit for dissolution testers has transformed from traditional “mechanical dial offline versions” to advanced “wireless digital online versions.
In the midst of the diverse array of mechanical validation toolkits available on the market, how should one make a selection? Today, I’m here to provide some insights. By understanding the following key points, you can easily find the toolkit that suits your needs.
- Compatibility of the Toolkit with Your Instruments:
For users with a variety of dissolution testers from different brands, selecting a toolkit that is compatible with all of their instruments is of paramount importance. Currently, dissolution testers available on the market can be broadly categorized into four types:
Fixed Head with Pull-Up Shaft Design:
Dissolution testers of this type provide ample external operating space around the vessel, and the lift height of the pull-up shaft is not restricted. As a result, conducting mechanical validation on such systems is relatively straightforward. Most of the toolkits available in the market are suitable for these testers. Representative dissolution testers falling under this category include Copley DIS600i/800i, Riggtek easy Diss TX8, and others.
Head Lifting, Non-Contact between Head and Dissolution Vessel Design:
In dissolution testers of this type, the rotational shaft typically supports quick detachment and reattachment but lacks the pull-up mechanism. Consequently, these testers might face issues where the bottom of the basket cannot be raised to a sufficient height above the dissolution vessel, preventing the measurement of basket oscillation. Representative dissolution testers falling under this category include Agilent 708-DS and Shimadzu SNTR 8400A.
Head Lifting, Head in Close Proximity to Dissolution Vessel Design:
In this type of dissolution testers, due to the lack of visibility of instrument readings from the dissolution vessel opening, the use of mechanical dial offline version toolkits for validation is generally not possible. Moreover, the limited space at the burner’s mouth prevents the utilization of online toolkits that require external support. A representative dissolution tester of this category is the Sotax AT Xtend.
Hinged Head Design:
Dissolution testers with a hinged head design are somewhat similar to the “Head Lifting, Head in Close Proximity to Dissolution Vessel” type. Furthermore, because the rotational shaft is not vertically inserted into the dissolution vessel, apart from the inability to use mechanical dial offline version toolkits for validation, this type also places high demands on the internal testing item holder (as it’s prone to jamming). Representative dissolution testers of this category include Sotax AT-7 Smart and TianDa TianFa’s RC8MD.
With an understanding of these four types of dissolution testers, you can easily match your specific equipment to the corresponding category and ensure compatibility before purchasing a toolkit. Of course, toolkits capable of validating hinged head dissolution testers represent the industry’s highest standards. Such toolkits are the most versatile and widely applicable. Opting for a toolkit suited for hinged head dissolution testers is a prudent choice!
- Does the Toolkit Support In-Situ Testing?
When it comes to “in-situ testing,” many individuals might be hearing this term for the first time.
“In-situ testing” primarily refers to conducting real-time testing and analysis within the environment and conditions of a normal sample test. This contrasts with isolating a specific target for individual variable-based measurements or simulating conditions for testing. This approach allows for analysis under conditions closely resembling the experimental setting, leading to more accurate data.
Regarding the mechanical validation of dissolution testers, it can be understood as conducting measurements for all validation items under the normal operational testing state of the dissolution tester.
For instance, the measurement of basket oscillation has long been a challenge in the field, drawing significant criticism due to its inherent difficulty. To elucidate this, we offer a brief illustration using two accompanying images:
From Figure 1, it can be observed that this particular approach to basket oscillation testing involves elevating the rotating basket from its “in-situ” position to the mouth of the dissolution vessel. Subsequently, the instrument is affixed to a stand for measurement. We term this method as “non-in-situ testing.” However, this approach may not authentically replicate the actual oscillation of the basket within the dissolution vessel.
With the basket in Figure 2 positioned at a typical operational distance (25mm from the bottom of the dissolution vessel), and the fixed stand not impeding the normal operation of the dissolution tester, this measurement approach is referred to as “in-situ testing.” This methodology precisely mirrors the oscillation of the basket within the dissolution vessel.
Having reached this point, have you gained a clearer understanding of “in-situ testing”?
- Is the Calibration Cost Within Expected Range?
The calibration cost of a toolkit is an aspect often overlooked but holds significance in shaping user experience. The calibration cost of a toolkit primarily hinges on the number of instruments involved. Apart from inclinometers for leveling and verticality, specialized instruments like thermometers and tachometers, validation also involves instruments for coaxiality, basket/paddle oscillation, basket oscillation, and basket/paddle depth measurements. Various toolkit manufacturers configure their toolkits differently in terms of instrument allocation. Some allocate 1-2 instruments per validation item, while others share a single instrument across multiple items. This implies that a minimum of 4 instruments is typically required for a toolkit. It’s noteworthy that the calibration cost for eight instruments is generally twice that of four instruments.
Instruments Required for Standard Mechanical Validation Toolkit
04. Opt for Online Validation Whenever Possible
Offline versions of mechanical validation toolkits have gained popularity among dissolution tester users due to their user-friendly operation and affordable purchase prices. However, as demands for data integrity continue to rise and regulations impose stricter requirements on aspects like raw data storage, user access management, and audit trail records, it is advisable to choose a mechanical validation toolkit with terminal support. Such toolkits offer data collection, user management, and audit trail functionalities. This choice aligns with the evolving regulatory landscape and data integrity expectations.
Finally, I’d like to recommend a powerful mechanical validation toolkit for dissolution testers – the DissoMate MQ10 from Welch Materials. This toolkit offers the following features:
- Compatible with the majority of mainstream dissolution testers on the market.
- Enables in-situ testing, resulting in test data that better reflects the dissolution testing conditions and increased data accuracy.
- Wirelessly transmits all test data to the control terminal, automatically exporting verification reports after electronic signatures.
- Equipped with voice control capabilities, enabling a single operator to complete all validation items.
- Requires only 4 instruments, leading to more cost-effective annual calibration expenses.
- Includes user management and audit trail functionalities.
|Instrument part number||Name|
|MQ1006||Wobble test pack|
|MQ1007||Centering test pack|
|MQ1008||Depth test pack|