Dissolution Tester

Overview

A dissolution tester measures how fast a tablet or capsule releases its drug into solution. That release rate is one of the most important quality checks in pharmaceutical manufacturing: it predicts how the medicine will behave in the body, and a dissolution profile is part of nearly every drug's specification. The instrument reproduces, under tightly controlled conditions, the early steps of a dosage form breaking down in the gut.

The test is defined by pharmacopoeia methods, so the machine is built to hit exact tolerances. The medium must sit at 37 °C within half a degree, the stirring must hold its set speed within a revolution per minute, and samples must be drawn at precise times. Six or eight stations run in parallel so a batch is characterized in a single run.

How it works

The vessels sit in the Heated Water Bath, where an immersion heater and a circulation pump hold every station at body temperature; a thermal fuse guards the heater and an RTD closes the temperature loop. Seated in that bath is the Vessel Array, a row of round-bottom glass vessels, each capped by an evaporation cover ported for the shaft and sampling probe.

Agitation comes from the Stirring Drive. One motor turns a gear train and a shaft into each vessel, fitted either with a Paddle Element for USP Apparatus 2 or a Basket Element for Apparatus 1 that holds the dosage form in the flow. An encoder closes the loop so speed stays within a revolution per minute across all stations.

Samples are pulled by the Auto-Sampling System. A peristaltic pump draws medium through filtered probes at programmed times, valves route each pull to a fraction collector, and fresh media is metered back in to keep the volume constant. The Control & Display runs the whole method, temperature, speed, sampling schedule, with audit-trail logging, and the Frame & Cabinet carries the drive head on a motorized lift so the shafts raise clear for loading and cleaning.