Phytopharmaceuticals B.Pharm , University of Mumbai Guided by Prof. Dr. Babita Madam

1. Equipments for Drying
of Herbal extracts
PREPARED BY – ROHAN JAGDALE

2. Introduction
▪For herbal medicine end-products with added value, appropriate extraction procedures
(i.e., in terms of bioactivity), standardization of extracts, selection and tuning of the
drying processes operating conditions and design of pharmaceutical formulations are
also necessary.
▪Every plant matures in different cycles. This suggests that when you want to extract the
botanical essentials of your plants, the harvesting stage must be optimized. The leaves, stems,
and roots are primary parts of the herbal plants that provide optimal results when doing the
extraction process.

3. ❑Drying is the final stage in the primary steps of herbal processing. All plant materials must be
dried after sorting, washing, blanching, and leaching.
❑If you do not dry your plant materials after going through several steps of cleaning them, they
will be damaged by mold growth and other microbial infestations.
❑Drying will avoid the plant’s deterioration of tissue and phytochemical alteration caused by the
actions of harmful organisms. Drying will also help grinding and milling, which converts the
herbal materials into a more convenient form for the next processing series.

4. Equipments used for drying of herbal
extracts
❑Spray dryer
❑Fluidized bed dryer
❑Freeze dryer
❑Vacuum belt dryer
❑Vacuum tray dryer

5. Spray dryer

6. Spray dryer technology is used for natural extracts encapsulation with different carriers such
as maltodextrins or cyclodextrins.
In this work , a model of natural extract encapsulation was developed and validated at
different temperature and at different ratios between natural extract and carrier .
Merits –
•The drying process is very fast
•It can be dried into power directly
•Easy to change drying conditions and adjust product quality standards

7. Demerits –
◦ Spray dryer is bulky and also expensive to install
◦ Difficult to clean after use
◦ Solid materials can not be dried using spray dryers.

8. Fluid Bed Dryer
Fluidisation is promising alternative technology , which allows for simultaneous drying ,
encapsulation and agglomeration of herbal compositions in a single step , reducing operation
cost , saving time and generating coarse product with improved physiochemical properties
adequate for further processing in pharmaceutical , food and agricultural sectors .
Advantages –
• Fast and homogeneous drying
•Easy and less labour intensive
•Comes with wide range , capacities and sizes
Disadvantages-
Turbulence during fluidisation may cause attrition . Hence need to use binding agent

10. Freeze dryer

11. Freeze drying is applicable if sample contains moisture instead of organic solvent in the
herbal extract
Organic solvents may destroy some of the parts of the machine and it is not advisable
to freeze dry the herbal extracts that are extracted through organic solvents, only
temperature sensitive aqueous extracts should be processed through freeze drying
equipment .
Freeze drying does not use high temperature , its very good methos to dry extracts
without causing major changes on their properties .

12. Disadvantages –
◦ Freeze drying requires lots of energy and sometimes time .
◦ Sample need to be frozen completely before drying
◦ Large quantity of sample can cause damage to freeze dryer .

13. Vacuum belt dryer

14. ◦ Can use for all plant extracts
◦ Suitable for sensitive components such as vitamins and minerals
◦ Recommended for expensive extracts
◦ Protect active ingredients from damage because temp. is not to high .
◦ Disadvantage is , it requires high investment cost and high operation cost

15. Vacuum tray dryer

16. Same application as vacuum belt dryer
Equipment size is small compared to vacuum belt dryer hence suitable for low quantities of
extracts .