Advantages and disadvantages of various tablet manufacturing processes

Advantages and disadvantages of various tablet manufacturing processes

Tablets are one of the integral parts of the pharmaceutical industry. The design and manufacturing of which are complex and involve various steps and processes. A scientist makes sure that the right form and amount of drug substance is delivered at the exact time and location maintaining its chemical integrity, to get the desired results.

Most of the drug substances do not carry the desired properties that would give a satisfactory flow from the hopper to the die cavity of tablet presses. Thus, they are run through pre-treatment alone or with suitable excipients to produce free-flowing granules that are easily available for tabletting.

Tablets are generally manufactured by three processes, namely, wet granulation, dry granulation or direct compression. These processing methods involve several steps or unit processes like weighing, milling, mixing, granulation, drying, compaction, coating and finally packaging. Weighing, milling and mixing are common to all the three manufacturing processes and the subsequent unit steps differ in all. All of these manufacturing processes have their advantages and disadvantages. And manufacturers use them as per convenience and need.

Here the advantages and disadvantages of the three tablet manufacturing processes –

Wet granulation process -
It is the most commonly used method. Using water as the main granulation fluid, heat is applied to dry the formed granules. This procedure has sufficient mechanical properties and the quality of the tablet is affected by the choice and concentration of binder and the type and volume of granulation fluid. This method is not as efficient as others.

Advantages -

  • • Uses low concentration of the therapeutic agent
  • • Reduces intra and inter-batch variability due to decrease in segregation of formulation components during storage and processing
  • • Not dependent on the inclusion of special grades of excipients
  • • Tablets are responsive to post-processing unit operations

Disadvantages -

  • • Includes several processing steps
  • • Usage of various solvents may lead to drug degradation
  • • Enhances the hardness of the granule
  • • Application of heat might degrade the thermolabile therapeutic agents

Dry granulation process -
When the granulated ingredients are sensitive to moisture or heat, this procedure is implemented. Granules are produced without the aid of any liquid solution as the name suggests. This technique is used for the preparation of aspirin and other aspirin combinations for tablets.

Advantages -

  • • Both roller compaction and slugging require conventional grades of excipients
  • • No heat or solvent required
  • • Not associated with alterations in drug morphology

Disadvantages -

  • • Specialised equipment is necessary
  • • Issues regarding powder flow
  • • Tablets produced are softer than wet granulation leading to difficulty in processing techniques afterwards
  • • Reduced yield of tablets due to the generation of considerable dust
  • • Segregation of components might occur during post mixing

Direct compression process -
Without any pre-treatment of the powder blend when it is compressed directly from a powder mixture of API and suitable excipients, then the method is called direct compression. This is a dry process where the powdered tablet formulation is directly compressed into the tablets, without any specific physical nature modification of the former.

Advantages -

  • • Cost-effective due to lesser steps
  • • Does not require any solvents, thereby negating potential threats of unstabilised therapeutic agents
  • • Reduces transfer losses and contamination threats as lubrication and powder mixing are carried on the same vessel

Disadvantages -

  • • Special grade excipients are required
  • • Quality and uniformity of the tablet depends on the excipients
  • • Tablets produced are softer than wet granulation leading to difficulty in processing techniques afterwards
  • • The method is avoided when a colourant is required as resulting dosage form appear mottled

The primary goal of the manufacturing process of a tablet is to produce tablets that can withstand the mechanical shocks during the several stages of production until its usage. Also, the manufacturers have to consider its uniformity in weightage along with its chemical and physical stability to make it long-lasting.

Despite the advantages and disadvantages of these three manufacturing processes, the production of a tablet is determined based on the below-mentioned reasons -

  • • Chemical and physical endurance of the Active Pharmaceutical Ingredient (API) during the production method
  • • Compression characteristics of the API
  • • Availability of the significant processing apparatus
  • • Particle size of the formulation component
  • • Cost of the processes involved

Post the tablet manufacturing, the tablets are subjected to several pharmacopoeial or official or non-pharmacopoeial or non-official tests to determine their quality. Once they pass it, the tablets are commonly packaged using strip packs and blister and stored in low humidity and protected from extreme temperatures.

With few exceptions, tablets that are properly manufactured and stored can last for many years.

Meanwhile, the Indian pharmaceutical industry is expected to reach $55 billion by the end of 2020, growing at a CAGR of 22.4%. The pharmaceutical sector of India supplies over 50% of the global demand of various vaccines. India is also known as the lowest-cost producer of medicine in the world and boasts of being the largest exporter of generic drugs in the globe. Moreover, the coronavirus has also created a positive impact on the industry as the country produced almost 20 crore HCQ tablets that are supplied all across the world, as some research shows that the tablet is beneficial in treating the affected.