As a reaction to the increasing, worldwide requirements of the good manufacturing practice (GMP), NARA improves its pharmaceutical mill, SCM (Super Clean Mill) continually. It is based on the principle of a conventional pin mill, which suits the requirements of GMP in the pharmaceutical and the foodstuffs industry. The next generation mill, NARAs New SCM, is characterised by disk-structured components, which are positioned on bars. By the release of handwheels only, the complete assembly can be dismantled easily and by one person. The low heat increase during milling as well as the easy adjustment of the particle size by screen insets, the simple structure for fast and easy cleaning and maintenance are some of the specific features of this machine. The mill is equipped with various constructional elements, to prevent contamination e.g. the execution of the air-purged shaft sealing, the direct drive and the spatial separation from milling area and drive unit.

Pharma mill – NARA mill

As a reaction to the increasing, meanwhile worldwide requirements of the GMP standard, the NARA pharmaceutical mill, SCM (Super Clean Mill) was developed. It is based on the principle of a conventional pin mill, which suits the requirements of good manufacture practice (GMP) in the pharmaceutical and the foodstuffs industry. The low heating up during milling as well as the easy adjustment of the particle size by screen insets and the simple structure for fast and easy cleaning and maintenance are some of the advantages of this machine.

The mill is equipped with different constructional features, to prevent contamination e.g. the execution of the air-purged shaft sealing, the direct drive and the spatial separation from milling area and drive unit.

Further important items regarding the good manufacturing practice of the Super Clean Mill are: all product-contacted parts are made of stainless steel with a polished surface quality of Ra ≤ 0.8µm; utilized lubricants and seals are certified by the FDA or by an appropriate authority. In order to fulfil the safety requirements, the mill was equipped with safety switches, so that rotating parts cannot be touched. Optionally, NARA offers the particularly developed and patented double gas shaft seal for this machine, in order to ensure an even better protection against contamination. CIP (Cleaning in Place) and SIP (Sterilization in Place) are likewise available.

Characteristics

The Super Clean Mill was developed for continuous milling of different load quantities. Different screen sizes for the classification of the grinding material with diameters from 0.2mm to 5.0mm are available depending on requested results. The exchange of the screen is simple. Special machine characteristics are:

1. Flexible execution:

-         Pin- or blade rotor

- Discharge opening position is changeable

- Different product container sizes as a function of the capacity

2. Particle size:

-         Inlet < 10mm

-         Outlet dp₅₀ = 20-100µm

3. Capacity:

-         Min. ~ 100g; max. ~ 400kg/h

4. Application:

Pharmaceutics, food industry, fine chemicals, medicine, cosmetics, organic- and inorganic materials

5. As open or closed system available
6. Delivery as turn-key system
7. Contained grinding possible

Grinding of high-activity substances under Containment

The processing of newly developed active substances with increased efficiency requires changes in equipment construction and the operational sequences. Two important aspects thereby are: the protection of the operator from the active substances and the isolation of the product from impurities by the environment. In co-operation between PSL Ltd., England and NARA Machinery Co, LTD., the “Millbox” has been developed. It is a GMP conform pin mill, optimised for the use in a containment. The inserted mills are of the type Super Clean Mill, and are executable in different sizes. For toxic or mutagenic materials in small doses the employment of a mill in closed execution only is not sufficient due to product change procedures. These will lead to elevated contamination of the surrounding atmosphere. The operation in a containment however, offers very high protection. In the containment the gas flow takes place as follows: the pins on the mill rotor cause a constant gas flow from the containment over the charging hopper via the milling chamber to the filter and back to the containment. Through them the mill internal product transport will be ensure. The product lead to the hopper and remains after milling in the receptacle, which is connected at a split butterfly valve.

Regarding a suitable shielded product feeding devices an O.E.L of less than 1 Microgram/m³ can be achieved. Dismantling and cleaning of the mill takes place within the Millbox. This is done by means of half arm gloves. The position of these is adapted to the operator in ergonomically optimal position. A similar containment as that of the SCM is used also for other machines of the company NARA, i.e. the particle Standardizer “Nebulasizer” or the impact mill “Cosmomizer”. In our laboratory in Frechen, we have the possibility to do series of tests with customer´s material.