Filling machines dosator machine

There are two types of piston-tamp fillers dosator machines and dosing-disc machines. In a recent survey of equipment used in production, it was found that dosator machines are used slightly more frequently than dosing disc machines, with about 18% of the companies responding reporting that they use both types of filling machines [50]. 

Fig. 16 Typical force-time trace from an instrumented Zanasi LZ-64 automatic capsule-filling machine. PC, precompression resulting from dipping of dosator into the powder bed C, compression resulting from actual piston tamping R, retention force Ej, ejection D, drag force developing during retraction of piston. (From Ref. 38.)...

Fig. 24 The effect of percentage of sodium lauryl sulfate in the formulation on the dissolution of hydrochlorothiazide from capsules containing dicalcium phosphate as filler, 0.75% magnesium stearate, and filled on a dosator machine with 300 N tamping force (USP method 2, 900 mL 0.1 N HC1, 50 rpm). (Adapted from Ref. 71.)... 

JE Botzolakis, LE Small, LL Augsburger. Effect of disintegrants on drug dissolution from capsules filled on a dosator-type automatic capsule-filling machine. Int J Pharm 12 341-349, 1982. 

Figure 1 Dosator from a Zanasi LZ-64 intermittant motion filling machine.

A successful filling operation with these machines requires formulation attributes similar to those of dosator machines. Formulations require cohesiveness, and fillers that have been modified to enhance both their... 

Heda PK, Muteba, K, Augsburger LL. Comparison of the formulation requirements of dosator and dosing disc automatic capsule filling machines. AAPS Pharm Sci, 2002 4(3) article 17 DOI 10.1208/ps040317. http //www.aapsi. psj.org/view.asp art = ps040317... 

The fundamental requirements of a formulation to be filled on a dosator type machine are good flow properties, compressibility and lubricity. Plow is important in the powder bed when the dosator dips into the powder, it leaves a void which must be closed with material of the same bulk density prior to the next dosator entering that area of the hopper. Irwin et al. (1970) investigated the effect of powder flow on the uniformity of weight achieved on a Zanasi filling machine and concluded that the better the rate of flow the better the uniformity of fill. 

Auger or Screw Method. This was the first mechanism used in industrial-scale machines, although the dosator and piston tamp mechanisms have now largely superseded it. The capsule body in its holder passes beneath the powder hopper on a turntable. The powder is fed into the capsule body by a revolving archimedian screw. The auger rotates at a constant rate so the fill weight is related to the duration of filling that is related to the speed of rotation of the turntable. 

This mechanism is the most widely used mechanism and can be found on small pilot scale machines using an intermittent action similar to rotary machines capable of production rates in excess of 120,000 capsules per hour. As a result of its popularity, there have been considerable studies into the formulation of powder for filling on these types of machines and instrumentation of the dosators. 

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