Soft Gelatin Capsule Processing/ Manufacturing; How is it tricky?

Gelatin capsules are being used commonly for the past several years with proven safety and toxicity profile. Gelatin exhibits non-allergic properties, contains proteins that are easy to digest and easy to swallow. These capsules are widely accepted in the pharmaceutical industry.

There are several reasons why it is used widely in the market. Factors like, easy to administer, manufacture, liquid can be encapsulated (non-water soluble) in small to large sizes, producing specialised dosage forms etc. makes it one of the prominent dosage forms in the pharmaceutical industry.

Gelatin or Gelatine is moisture and temperature-sensitive, which makes the manufacturing process quite challenging for the manufacturers. While manufacturing and during the drying stage, if the air entering the dryer is not conditioned in terms of temperature and humidity, the Gelatin becomes brittle or the gel melts and does not solidify into a band. The Presence of High Rh also leads to microbial contamination, which is highly undesirable considering the application of Gelatin in the food and pharmaceutical Industry.

In one of the processes during manufacturing, warm liquid gelatine is spread over a slowly revolving stainless steel drum. A supply of chilled dry air congeals the gelatine as the drum rotates so that a tacky, elastic band rolls off the other end. This thin band is automatically formed into capsules, filled with medicine. If the temperature and humidity are too high, gelatine will remain soft and prevent solidification. From the encapsulating machines, the soft moist capsules are transferred to drying drums or chambers for rapid drying.

In the case of encapsulation and packing, the required level of humidity is 30±5% at 23 degrees centigrade. However, the drying is done at 15±5% at 20 degrees centigrade. The drying of soft gel capsule is very tricky, as it has to be dried in very controlled temperature and humidity conditions, both of which should not exceed 20 along with specific air changes and laminar airflow for uniform drying including time for drying. The moment any of the conditions deteriorate, the capsule may get brittle, extra soft, etc.

Moisture is the biggest menace for the pharmaceutical industry because the majority of pharmaceutical products are highly hygroscopic and tend to suffer physical, microbiological and biochemical deterioration after coming in contact with moisture. Thus, each pharmaceutical manufacturing process requires highly controlled environmental conditions before the finished product is packaged and finally reaches the customer.