Key Challenges in Scaling up Production Process

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Scale-up is generally defined as the process of increasing the batch size. Scale-up of a process can also be viewed as a procedure for applying the same process to different output volumes. Sanjeev Jain, a process scale-up specialist, enlightens readers on the process of Scaling –up, the challenges generally faced and practical solutions.

We use the term Scale up to refer to the production of an increased batch size of a product. If a product is successful, then you may scale-up multiple times throughout the product’s life cycle to meet growing demand. Scale-up in cosmetics manufacturing is the migration of a process from the lab-scale to the pilot plant scale or commercial scale. In the journey from laboratory to market, scale-up is part of product research and development (R&D) and optimization of production resources. Hence, the prospect of manufacturing a product at a commercial-scale should be considered when new formulations are in the R&D phase itself. Any processes involved in fabricating the product must be scalable in terms of safety furthermore efficacy, and economic factors must also be considered. Understanding what scale-up is and how it will make it easier to incorporate into the R&D phase itself

Image for illustration purpose only.

Process Scaling up for Cosmetics & Personal Care industry

In the cosmetic industry, new products must get from the lab to manufacturing as quickly as possible. This is the job of the Process department, and the process is called scale-up. At the product development labs, studies using 500 -1000 grams quantity are conducted. Lab samples are used to confirm product efficacy, sensorial appeal, packaging suitability and effects of colour and fragrances. Lab samples are also used to determine product stability and product safety. Once the product formulation is ready after laboratory studies are conducted, it is taken for the pilot plant scale-up. Pilot plant machinery is nearly identical to that of commercial plants. Generally, quantities of 50kg/litres are used here. They are produced for sensory, chemical, microbiological evaluations, for limited market testing or furnishing samples to potential customers, for shelf-life and storage stability studies. Pilot plant results are then evaluated for the product as well as the process. Economic adjustments are made for any correction and decisions taken to proceed with full-scale plant development.

Primary Challenges during Scale-up and potential solutions

  • Mixing –Some mixing problems develop simply because of the increased batch size. Mixing several thousand litres is more challenging than a similar operation in a lab or pilot plant. The Choice and design of mixing equipment are critically essential to a robust manufacturing operation and product reliability from batch to batch. The RPM of the motor, frequency controller, temperature controller, CIP lines vacuum, transfer, filling lines and machines and necessary adjustments should be as per needs. Circulation lines and sampling system to control critical points, e.g. free alkali in shave gels, pH in face washes are critical. Duration of mixing time, along with circulation systems, should be monitored closely. Excessive foaming by mixing under vacuum should be avoided. Water lost should be checked and readjusted from time to time. Pay special attention to critical product category, transparent products (toothpaste gel, shave gel, face wash, HR cream, hair colour, etc). Focus on the management of mixing instructions per operation, with the specification of the sequence for mixing additives and option to change the sequence and other parameters when using alternate material.
  • Calculating Safety Stock (Minimum Inventory)
    Based On Material Usage during a Given Period and material requirements planning(MRP)one has to calculate the safety stock of ingredients because the critical nature of the finished product depends on it. The calculation is performed based on actual material usage during a defined period and includes the possibility of adding extra doses after reconciling the batches. Cross-check the raw material quality by making small trial batches in the lab before starting bulk production after getting QC approval. For products like shave gel, hr cream, hair colour, calculate ten times quantities of actual batch size compared to simple products where we should calculate five times. Cross-check and ensure in advance with each RM supplier to supply RM in case of urgent need.
  • Critical Parameters of the process optimization Even small changes in manufacturing conditions, or “process variables,” can often significantly affect its perceived quality or shelf life. Hence conduct pilot design studies with equipment to be used in a final manufacturing plant. Process variables are often difficult to identify and control precision. Ensure the plant has provisions for process and environmental controls, cleaning and sanitizing systems and meeting all regulatory requirements. Depending on the formulation, the product may degrade during shipment to produce discolouration, bad odour or visible phase separation. Optimization can be done by adjusting Speed of the Homogenizer, Mixing Time, Condition of the temperature and Heating time.

Fine-tuning of the Formulation – Here are critical attributes and the precautions you should take

  • Colour- Select as per base formula.
  • Preservative Dose – Calculate lipid, solvent and water content
  • Clarity- Optimize Content
  • Moisture- Check the Ingredients physical & chemical properties
  • pH or Free Alkali/Acidity – Optimize acid or Alkali or set Buffer
  • Foam Height – Optimize the concentration
  • Particle Size Of Emulsion – Depends on insoluble Ingredients
  • Thickener Dozing – Optimize the concentration
  • Texture, Sensory and Rheological Profile – Control the manufacturing process
  • Globule size of Emulsion – Optimize the manufacturing process with speed and time

 Stability Testing of Cosmetic Products

Stability Tests are often performed at 37°C, 40°C or 45°C and sometimes 55° also across 1, 2, 3months. The temperature used and the duration depends on the product type. Important parameters to be finalized to predict shelf life Colour, odour and appearance; Changes in the container/Packaging; pH level; Viscosity and Weight changes. Conduct Microbial tests demonstrating the ability of the products to prohibit microbial growth during normal use and other specific tests if necessary.

  • Water, Machine, process parameters should be the same
  • Final packing should not react or disturb the product specifications.
  • Raw material should be used of the same company and same grade at each(lab, pilot and scale-up) stages.

It is impractical to think that production scale-up will take place without modifications and accomplishments in the lab batches will transform directly into success in commercial production batches. Hence, planning for scale-up should begin when lab studies have commenced. The plan can then be modified as more complete information and knowledge is gained.

Author : Sanjeev Jain 

Sanjeev Jain is a veteran in the cosmetic industry with a vast experience of more than 30 years. He has been associated with organisations such as Unilever, Lotus Herbals, Ozone Ayurvedics, Oriflame, Yashan BioScience and more. One can reach out to him for Technical Services and Scale-up Operations Management, Cost Management of RM / PM to achieve the Budgeted cost of formulations and packaging and Management of Technology and New Product Innovation.