INTRODUCTION TO DISSOLUTION TESTING

Tablets or capsules taken orally remain one of the most effective means of treatment available. The effectiveness of such dosage forms relies on the drug dissolving in the fluids of the gastrointestinal tract prior to absorption into the systemic circulation. The rate of dissolution of the tablet or capsule is therefore crucial.

One of the problems facing the pharmaceutical industry is to optimise the amount of drug available to the body i.e., its ‘bioavailability’. Inadequacies in bioavailability can mean at best that the treatment is ineffective and at worst potentially dangerous (toxic overdose).

Drug release in the human body can be measured ‘in-vivo’ by measuring the plasma or urine concentrations in the subject concerned.  However, there are certain obvious impracticalities involved in employing such techniques on a routine basis. These difficulties have led to the introduction of official ‘in-vitro’ tests which are now rigorous and comprehensively defined in the respective Pharmacopoeia.

The principal function of the dissolution test may be summarised as follows:

• Optimisation of therapeutic effectiveness during product development and stability assessment
• Routine assessment of production quality to ensure uniformity between production lots
• Assessment of ‘bioequivalence’, that is to say, production of the same biological availability from discrete batches of products from one or different manufacturers. 
• Prediction of ‘in-vivo’ availability i.e., bioavailability (where applicable)

 
Although initially developed for oral dosage forms, the role of the dissolution test has now been extended to ‘drug release’ studies on various other forms such as topical and transdermal systems and suppositories.

We offer all your dissolution accessories including:

•  Baskets - including special polyurethane suppository baskets
•  Paddles
•  Shafts
•  Paddle over Disc (USP Method 5) for Transdermal Delivery Systems
•  Rotating Cylinder (USP Method 6) alternative for Transdermal Delivery Systems
•  Special mini cell(vessel) and paddle for transdermal studies of topical preparations such as liquids, suspensions, gels and ointments  

WHY AUTOMATE?

Dissolution testing is now one of the most common analyses employed in the pharmaceutical industry. The ever increasing demand for dissolution testing means that a minimum of 6 and possibly up to 24 individual tests may be required per batch of formulation. Further, the increasing use of delayed release preparation means that such tests may extend over 12, 24 hour or longer periods. Manual dissolution testing is tedious and labour intensive. For these reasons, automated tablet dissolution systems are becoming of increasing importance to improve efficiency and reproducibility.

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