Evaluation Of Pharmaceutical Tablet

Tablets are a solid dosage form of medicaments with or without excipients which are prepared by compression or moulding method and intended for oral administration for local and systemic effect. They may vary in size, shape and weight depending on the medication and its mode of administration.

Tablet evaluation

Quality Control Tests For Tablets

Quality control is a small part of quality assessment (QA) and it is concerned with sampling, testing and documentation during manufacturing and also after completion of manufacturing. It is the monitoring process through which the manufacturer measures actual quality performance, compares it with standards and finds out the causes of deviation from standard to ensure quality product not once but every time. In general terms, quality control refers to a procedure or a set of steps taken during the manufacturing of a product to ensure that it meets requirements and that the product is reproducible.

Read Also: General Properties Of Pharmaceutical Tablet

Types Of Quality Control

We have official and unofficial tests.

1. Official tests: Weight variation test, drug content, disintegration time test and dissolution test

2.Unofficial tests: Thickness, hardness, friability and organoleptic characters

Official Test

Weight Variation

Weight variation is calculated by weighing individual tablets and calculating the average weight and finally comparing the individual tablet weights to the average. The formula is (IW-AW)/AW×100% where the answer is in percent and;

IW: individual weight

AW: average weight

Factors Responsible For Weight Variation

1. Flow properties

2. Degree of segregation

Disintegration Test

This is the process of tablets breaking into smaller particles or granules given a set of conditions. This test is valuable for tablets that are intended to be swallowed and not chewed or sucked or effervescent. No disintegration time for sustained release and controlled release tablets. There is a machine that does this test.

Dissolution Test

When a dosage form is swallowed, the rate at which it releases the active ingredient is critical to ensure that the drug is delivered properly. The rate at which the drug is released is called the dissolution rate. Adrig can disintegrate but not available for absorption. There are different machines for this test.

Content Uniformity Test

Content consistency of active drug substances is crucial for tablets. The content of each product and each batch of each ingredient must be the same.

Factors Affecting Drug Content

1. Tablet weight variation

2. Uneven distribution of the drug in the powder or granules

3. Segregation of the powder mixture or granulation during formulation processes. It requires chemical assay based on the content.

Unofficial

Thickness Test

This is the determination of the diameter of the tablet. Micrometer and vernier caliper are used for checking tablet thickness.

Factors Affecting Thickness

1. Size and size distribution

2. Compression force

Hardness Test

Also known as “Crushing Strength Test" is the force required to break a tablet in a diametral compression test. This is necessary because strong or hard tablets can withstand mechanical shocks during manufacture, packaging and shipment. There are different machines used such as Monsanto hardness tester, Pfizer hardness tester, Strong cobb hardness tester and Erweka hardness tester.

Read Also: Types And Classification Of Pharmaceutical Tablet

Factors Affecting Hardness

1. Concentration of binder

2. Moisture content

3. Compression force

Friability

Friability testing is a method, which is employed to determine physical strength of uncoated tablets upon exposure to mechanical shock and attrition. Roche friabilator tester is most commonly used for determining % friability of tablets. Friability can be calculated by following formula- % Friability = W1 – W2/W1 × 100 Where, W1 = weight of tablets before testing W2 = weight of tablets after testing.

Organoleptic Properties

1. The colour of a product must be uniform within a single tablet. Non- uniformity is referred to as ‘mottling’ and hence it leads to poor quality of product

2. The presence of odor in a batch of tablets could indicate stability problems. However, the presence of an odor could be characteristic for the drug (vitamins), added ingredients (flavoring agents) or the dosage form (film-coated tablets)

3. Taste is important in consumer acceptance of, especially, chewable tablets