INSTRUMENT SELECTION GUIDE
Select a dissolution tester by the pharmacopoeial method your laboratory must run
Dissolution testing equipment is bought against a method, not against a brochure. The pharmacopoeial apparatus your syllabus or QC protocol names – Apparatus 1 (basket) or Apparatus 2 (paddle) being the common teaching and release-testing choices – decides the vessel, shaft, sinker, sampling and documentation questions you must put to any supplier. This guide converts a dosage-form requirement into a comparable quotation, and states plainly where a configuration must be confirmed in writing.
Start from the method, not the instrument
Teaching laboratories
A B.Pharm or M.Pharm practical usually demonstrates Apparatus 1 and Apparatus 2 operation, medium preparation, sampling discipline and calculation of dissolved active. The teaching requirement is visibility, correct vessel geometry and repeatable speed and temperature control – not validated release testing.
Institutional QC and research
A laboratory running protocol-driven testing must match the registered method: apparatus type, medium, volume, temperature tolerance, rotation tolerance, sampling schedule and the calibration or performance-verification evidence the protocol demands.
Tender and procurement teams
A BOQ line that says only “dissolution apparatus” invites non-comparable offers. Convert it to the fields in the RFQ checklist below so every bidder states the same facts, and record each deviation against the line item.
Seven decisions that determine the instrument you actually need
| Decision | Buyer must define | Offer must identify | Evidence to review |
|---|---|---|---|
| Apparatus type | Apparatus 1 (basket), Apparatus 2 (paddle) or other named pharmacopoeial apparatus the method requires | Which apparatus types the offered configuration supports and what is included | Offered specification and vessel/shaft geometry |
| Station count | Samples per run and weekly throughput | Number of vessels and stations in the offered model | Vessel count and layout drawing or photograph |
| Vessel volume | Medium volume the method specifies | Vessel capacity offered | Vessel specification with tolerances |
| Temperature control | Required medium temperature and the tolerance the method allows | Heating arrangement, control range and displayed resolution | Control description and any verification arrangement |
| Speed control | Rotation speeds the methods use and acceptable tolerance | Speed range, control type and displayed value | Drive description and speed verification approach |
| Sampling | Manual or automated sampling, schedule, and where samples go | Sampling arrangement offered, included or optional | Sampling accessory list |
| Documentation | IQ/OQ or calibration documents your quality system requires | Which documents are offered with the model | Document list per model, in writing |
Write the apparatus type, medium, volume, temperature, speed, sampling and documentation requirement into the BOQ line. Then every offer is comparable line by line, and every deviation is visible before the order.
Apparatus 1 and Apparatus 2: what changes for the buyer
Apparatus 1 – basket
The dosage unit is held in a rotating basket. Selection questions: basket mesh and material for the dosage form, shaft alignment, whether sinkers are needed, and how the basket is cleaned between runs. Floating or encapsulated formulations often drive the basket-versus-paddle decision.
Apparatus 2 – paddle
The dosage unit rests in the vessel with a rotating paddle above it. Selection questions: paddle geometry and position, sinker use for floating forms, deaeration practice for the medium, and observation access for teaching demonstrations.
The full procedure, medium preparation and acceptance criteria are covered in the dissolution apparatus experiment guide. This page deliberately does not repeat the procedure; it owns the purchasing decision.
Documentation and verification questions
Ask each supplier to state, in writing, which of the following are offered with the quoted model: operating and maintenance manuals, installation and operational qualification documents where applicable, calibration or performance-verification arrangements, and the spare-parts route for vessels, shafts, baskets, paddles and seals. A teaching laboratory and a QC laboratory need different depths of documentation – state which one you are.
Copy-ready RFQ brief
We are selecting dissolution testing equipment for [institution/department, teaching or QC use]. Dosage forms and methods: [immediate/sustained release, Apparatus 1/2, medium and volume]. Station count and throughput: [details]. Temperature and speed control required: [values and tolerances]. Sampling arrangement: [manual/automated]. Documents required: [manuals, IQ/OQ, calibration or verification records]. Please identify the exact offered model, vessel and station configuration, included baskets/paddles/sinkers, temperature and speed control description, sampling accessories, cleaning arrangements, utilities required and documentation supplied. Mark every deviation, exclusion and optional item, and state installation, training, acceptance, warranty and spares responsibility for delivery to [destination].
Questions buyers ask before ordering a dissolution tester
Do we need Apparatus 1, Apparatus 2 or both?
Follow the method your syllabus or protocol names. Teaching programmes commonly demonstrate both; a QC laboratory buys the apparatus its registered methods require. Confirm the offered configuration supports the named apparatus with the correct vessel, shaft and accessories.
How many stations do we need?
Work from samples per run and weekly throughput. A six-station arrangement is common in teaching; higher station counts suit batched QC work. Buying more stations than the timetable uses ties up budget; buying fewer creates scheduling bottlenecks.
What temperature and speed control should we require?
State the medium temperature and rotation speeds your methods use and the tolerance they allow. Ask the supplier to describe the control arrangement and displayed resolution, and how control performance is verified.
Which documents should come with the instrument?
Operating and maintenance manuals at minimum. QC-oriented buyers should also specify installation/operational qualification and calibration or verification documents in the RFQ so the offer states exactly what is provided.
Can one instrument serve teaching and QC?
Only if the offered configuration meets the stricter of the two requirement sets, including documentation. State both uses in the enquiry and require written confirmation rather than assuming a teaching unit satisfies protocol testing.
Scope note: this guide describes method-driven selection decisions. It does not state prices, delivery times, certification status or regulatory approvals, and it does not replace the pharmacopoeial text that governs your method. Model-specific configuration is confirmed in the written quotation.