Pharmaceutical Tablets Overview

Tablet Evaluations

• Tablets are a unit dosage form, offering accurate dosing and ease of handling, storage, and dispensing.
• Tablet manufacturing costs are generally lower than for other dosage forms, such as capsules.
• Their release profile is controllable.

Advantages and Disadvantages of Tablets

• Advantages:
  • Accurate dosing unit
  • Easy to handle, store and dispense
  • Easier to package and ship compared to capsules
  • Lower manufacturing cost compared to other dosage forms
  • Easily controlled release profile
• Disadvantages:
  • Some drugs resist compression
  • Difficulty masking bad taste or odor of active pharmaceutical ingredients (APIs)
  • Some drugs have poor wetting properties, making formulation challenging
  • Some drugs degrade during oral administration
  • Some may be difficult to formulate and package.

Types of Tablets

• Various tablet types exist, including enteric-coated tablets, vaginal tablets, lozenges, and many others. Different formulations meet specific needs.
• Specific examples of tablets were shown, including Canesten GYN and Strepsils.

Granulation

• Fine powder drugs often exhibit poor flow properties.
• Granules have enhanced flowability and compressibility over individual ingredients.
• Granulation ensures consistent API distribution throughout the formulation.

Compression

• Compression is the final step in tablet manufacturing.
• Factors involved, like die settings and forces, are outside the scope of current lecture.

Tablet Evaluation (General Appearance)

• General appearance is crucial for patient acceptance and quality control.
• Attributes like size, shape, color, odor, taste, texture, flaws, and markings must be evaluated.
• This quality assurance step monitors manufacturing processes while ensuring customer satisfaction.

Unique Identification Markings

• Unique markings are crucial for rapid product identification.
• Markings should include company name, product code, and potency.
• They are free of flaws for accurate and complete identification. Images of specific examples were shown, including valsartan 80mg and aspirin 325mg tablets.

Organoleptic Properties

• Color is vital for identification, influencing consumer acceptance.
• Uniform color is necessary within each tablet.
• Mottling (uneven color distribution) can indicate formulation or stability issues, affecting patient acceptance.
• Odor could point to stability problems, like in degrading aspirin tablets.
• Taste varies depending on the formulation, particularly relevant for chewable tablets.
• Visual flaws affect patient acceptance and can point to formulation problems; e.g., chips, cracks, and foreign bodies.

Tablet Size and Shape

• Tablet shape and diameter are determined by the die shape and are fixed.
• Thickness is the only dimensional variable related to the manufacturing process, and it should be uniform from batch to batch.
• Thickness variation should not exceed ± 5% to avoid packaging issues and maintain content uniformity.

Tablet Hardness

• Hardness relates to disintegration time for tablets during manufacturing, shipping, and handling.
• Factors like die filling, compression force, and binder amount can affect tablet hardness.
• Measurements can be done by machines such as those from Monsanto or Pfizer.

Tablet Friability

• Friability is another measure that ensures intactness when subjected to mechanical pressure during shipping and handling.
• A friability test measures how much of a tablet's weight is lost in the process.
• Acceptable loss depends on tablet type and formulation.
• The tester in use was referred to as the Roche friabilator.

Drug Content and Release

• A physically intact tablet might not produce the desired effects if drug content or release is inconsistent.
• Weight variation, content uniformity, disintegration, and dissolution tests must match expectations from batch to batch.

Weight Variation

• Weight variation measurements help ensure consistency in the amount of therapeutic agent per tablet.
• Weight variations are measured using USP weight limits.
• Factors that influence weight inconsistencies include flow characteristics of the tablet formulation and machine setup.

Content Uniformity

• Ensuring that the variation in active pharmaceutical ingredient (API) within each tablet is consistent compared to expected values.
• Uniformity is critical for reliable dosage and treatment efficacy and is within USP limits.
• Three factors directly affect uniformity: nonuniform API distribution, segregation during manufacturing, and tablet weight variation.

Disintegration Test

• The disintegration process breaks down a tablet in smaller particles and granules, typically done in a USP disintegration apparatus.
• Testing determines how quickly the tablet dissolves into smaller pieces or granules, essential for bioavailability.
• Enteric-coated tablets are expected to remain intact for at least an hour in the disintegration apparatus

Dissolution Test

• Dissolution tests gauge the rate at which the active drug dissolves into a solution, impacting absorption.
• Results are typically plotted as percentage of drug release versus time.
• USP dissolution apparatus is used to ensure comparability.

Tablet Evaluation Summary (Table)

• A chart summarizing various factors for evaluating different tablet types, along with their importance and potential issues.

Importance of Dissolution Testing

• It guides formulation and product development toward product optimization.
• Manufacturing is monitored by dissolution testing.
• Consistent in vitro dissolution testing is crucial for bioequivalence between batches and countries.

Processing Problems

• Tablet Issues:
  • Capping, lamination
  • Cracking
  • Chipping
  • Sticking
  • Picking
  • Mottling
• General Causes:
  • Air entrapment
  • Compression
  • Deformational issues within excipients (e.g., binders, lubricants, including too much water or low melting points of substances like stearic acid)
  • Errors in the formulation.
• Causes associated with Die Filling:
  • Inconsistency in die filling (dimension or weight variations)
  • Improper granule mixing/size distribution, poor granule mixing, uneven granule sizes
• Causes associated with Poor Flow:
  • Insufficient lubricant and glidant
  • Poor hooper design
• Causes associated with Poor Mixing:
  • Insufficient distribution of lubricant and glidant

Solutions to Tablet Problems

• Slowing compression speed and decreasing pressure can help reduce air entrapment.
• Use pre-compression to pre-shape the tablet before final compression.
• Proper selection of excipients (such as the use of appropriate binders and lubricants are needed).
• Consider changing tablet shapes to reduce fracture tendency (such as flatter shape).
• Adjust the amount of lubricant and drying for granules to eliminate sticking or picking.
• Improve granule mixing and reduce granule size uniformity to reduce uneven breakage.

Explore the various types of tablets used in pharmaceuticals, including their advantages and disadvantages. This quiz covers aspects like dosage accuracy, manufacturing costs, and challenges in formulation. Test your knowledge on tablet evaluations and formulations.