Aspects of the Lubrication Requirements for an Automatic Capsule Filling Machine

Abstract

A BS "HA C T Pspects of the lubrication requirements f o r an automatic capsule filling machine, instrumented to monitor compression and ejection forces, were studied under various filling conditions. Three common capsule fillers (compressible starch, microcrystalline cellulose, and anhydrous lactose) were filled into No. 1 gelatin capsules. Two main sets of runs were made. The first set was designed to study the influence of powder bed height, piston height and compression force on the ejection forces generated during the filling process. The second set was aimed at comparing lubricant type and levels. It was shown that the ejection force is increased by increasing the powder bed height, piston height and compression force. Compressible starch and microcrystalline cellulose required relatively low levels345 Copyright 0 1978 by Marcel Dekker, Inc. All Rights Reserved. Neither this work nor any part may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, microfilming, and recording, or by any information storage and retrieval system, without permission in writing from the publisher. Drug Dev Ind Pharm Downloaded from informahealthcare.com by Fudan University on 05/15/15 For personal use only. SMALL AND AUGSBURGER of magnesium stearate as compared to anhydrous lactose. The performance o f stearic acid and especially magnesium lauryl sulfate compared favorably with magnesium stearate in compressible starch. Drug Dev Ind Pharm Downloaded from informahealthcare.com by Fudan University on 05/15/15 For personal use only.

Comparison of the formulation requirements of dosator and dosing disc automatic capsule filling machines

“…For both machines, ejection force also increased as the compression force employed increased, confirming previous observations. 3 It is interesting that the ejection forces recorded at equivalent compression forces for these unlubricated fillers were higher on the Zanasi machine than on the HK machine. For some of the comparisons, fill weights were slightly higher on the Zanasi machine, which suggests that those plugs were slightly longer and thus would present greater frictional resistance to ejection.…”

“…As discussed previously, materials that exhibit substantial elastic behavior may recover differently in the 2 machines, thereby leading to greater ejection forces in the dosator machine. While it is conceivable that such a theory could apply to the lactose-based model lubricity formulations, lactose exhibits substantially less elastic recovery than Starch 1500 5 and a substantially higher lubricant requirement than either Starch 1500 3,5 or microcrystalline cellulose. 3 Clearly, any possible greater powder shearing in the dosing disc machine, as suggested by Ullah and colleagues, 19 would tend to increase the lubricant efficiency in that machine, thereby leading to easier ejection.…”

“…Formulators commonly regard lactose, the most widely used filler in hard gelatin capsule formulations, to have a greater lubrication requirement than microcrystalline cellulose or Starch 1500. 3 Since the level of magnesium stearate was reported to have little or no effect on the compactibility of lactose plugs formed in a dosator machine (based on plug breaking force measurements), 12 blends of anhydrous lactose, dt grade, and magnesium stearate were used to create the model lubricity formulations. The blends were mixed for 5 minutes.…”

“…For example, an MG2 machine simulator was employed by Jolliffe and Newton. 1 Cole and May, 2 Small and Augsburger, 3 and Hogan and colleagues 4 are among the many investigators who have reported on research involving Zanasi filling machines. Britten and colleagues 5 conducted research with an apparatus that simulates the action of a Macofar dosator machine.…”

“…[6][7][8] However, no systematic study comparing the formulation requirements of dosator and dosing disc machines has been published. Such research would provide critical guidance to formulators concerned with 1 scaling up development batches to larger machines of a different type, 2 making postapproval equipment changes, or 3 developing formulations that would run on either type of equipment.…”