Fluid Extracts

Manufacture of fluid extracts from raw medicinal herbs is a satisfying and rewarding process, with the aim of producing a high quality product that meets set specifications.

At Herbs in a Bottle we use two pharmacopoeia techniques to create fluid extracts - maceration and percolation.  

Maceration is the pre-soaking of the raw herb in a prescribed strength and quantity of menstrum for a minimum period of twelve hours.  This allows complete penetration of solvent through the cell walls of the plant materials and diffusion of cell contents into the menstrum.

Percolation is a process undertaken in stainless steel conical percolators which facilitates extraction by the processes of diffusion and washout - the continuous movement of menstruum against plant cell walls maintaining high concentration gradient and an efficient extraction.

The manufacturing process is scheduled by Production Managers who check the availability of raw materials, determine the required production volume and issue Works Orders with a product batch number.

Labels are issued for percolators and buckets to ensure every stage is carefully recorded (and the records will be reconciled and checked by the appropriate superviser).

Raw materials are requested by means of the Works Order.  The stock is picked by batch number.  Careful weighing takes place and the raw herbs are delivered to the production area.

The required solvent for that particular herb will be requested (for instance, a 1:1 45% of Valeriana officinalis rad requires one part macerate to one part menstruum, solvent system 45% Ethanol v/v in water).

Equipment used includes macerating bins (which are white buckets fitted with white lids that provide an air tight seal); conical 50 litre stainless steel percolators; filter discs; funnels and collecting bins.  All equipment must be thorough cleaned before and after use, and inspected as clean by our QC department.

The raw materials are then weighed directly into the clean labelled macerating bins (cleaned and sanitised).  Hygiene checks are carried out by a supervisor.  The required amount of solvent is measured out in a graduated stainless steel bucket.  Each bin is filled with the required amount of liquid and then sealed and transferred to the maceration area where it is left for a minimum soak time of twelve hours.

The percolators are prepared, and the filter discs covered with muslin dampened in pure water.  The lid, funnel and stopper are assembled.  The pre-soaked material is divided and carefully loaded into the percolators and tamped.  The required amount of solvent is measured and poured into the percolator.  The vessel is closed and transferred to the extraction area.  

Percolator taps are opened after a short standing time and the date and start time recorded.  Flow rate is a fast drip of ten drops per second.  The rate of percolation is carefully monitored and is influenced by gravity and osmosis.  

Intermediate QC tests are carried out during percolation, observing strict hygiene procedures (the QC supervisor wears gloves, jugs and ladles are sanitised, nothing must be put on the floor etc).  

At completion further QC tests take place to ensure the liquid meets the specification.

Following completion a thorough equipment clean takes place (using a specified detergent then soaking, scrubbing, sanitising, and comprehensive rinsing).

Following the equipment clean down a thorough area clean takes place.

Of course, this is just a brief precis of the production procedure - you are very welcome to visit our Essendine facility to see the full process in operation.

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