CONFERENCE REPORT

Pharmaceutical and Medical Packaging

By Yngve Dagel*

The 9th Annual International Conference and Exhibi-tion on Pharmaceutical and Medical Packaging tookplace in Copenhagen on 18±19 May, 1999. It wassponsored by the Society of Plastics EngineersScandinavia and co-sponsored, among other orga-nizations, by IAPRI, The International Associationof Packaging Research Institutes.181 participants from 17 countries discussed 24

papers and 41 organizations exhibited their pro-ducts. This very well-organized conference is wellestablished as an annual forum for the presenta-tion of new technology and scienti®c results in thepharmaceutical and medical ®elds.The papers covered a wide range of interests,

impossible to report here. We report here aselection of four papers and at least two paperswill be published in full in future issues ofPackaging Technology and Science.

Application of Time Temperature Indicators(TTI) to Pharmaceutical Packaging to MonitorShelf Life of Temperature Sensitive Products by

Peter RoÈnnow, Ph.D. He is Vice President ofTechnology and Techniques of Visual IndicatorTag Systems AB in MalmoÈ , Sweden.

Modern industry, producing and handlingperishable and temperature-sensitive productssuccessfully controls temperature during manu-facturing. When the products are transported anddistributed the tight control is lost. Open datinghas been introduced as an attempt by theauthorities to help customers to distinguish a goodproduct from a questionable one.

Unfortunately, if the product was temperature-abused during transit, the customer has no way ofknowing if the product is satisfactory or not, evenif the open date is still good. The scienti®ccommunity has for some time tested and evaluatedtime±temperature indicators, TTIs, as a simple andef®cient tool to monitor and control distribution,and has recommended them as an effectivealternative to, or as a complement to open dating.

The basic technical requirement for a TTI is thatthe temperature behaviour can be well described

Table 1. Characteristics of different TTI types

Reaction type Colour signal Range of Ea

LifeLine2 Chemical polymerization Darkening of centre of bulls-eye window 20±24 kcal/mol3M Monitor Mark1 Physical diffusion of chemical solute Coloured front migrating on white wick 8±12 kcal/molVITSAB1 Chemical enzymatic hydrolysis of lipid Colour change in window from green to yellow 12±27 kcal/mol

PACKAGING TECHNOLOGY AND SCIENCEPackag. Technol. Sci. 12, 203±205 (1999)

Copyright 1999 John Wiley & Sons, Ltd. CCC 0894±3214/99/040203±03 $17.50

* Correspondence to: Y. Dagel, Seglarvagen 5, S-181 62 Lidingo, Sweden.

with the Arrhenius kinetic model. The three maintypes of TTI indicators produced in the worldtoday meet this requirement. (See Table 1) Animportant point is to activate the TTI at a ®xedtime. This can be managed either by breaking aseal separating the active ingredients or keeping itdeep frozen until use.During the past two years, TTI has been applied

to food products, such as fresh salmon ®llets, freshcat®sh, cut salad and ground beef. The authorstates that TTI is well suited to control tempera-ture-sensitive pharmaceuticals during transport.

Non-destructive Package Leak Detection in theFood Industry by E. Hurme, MSc. He is a SeniorResearch Scientist at VTT Biotechnology and FoodResearch in Espoo, Finland.Package integrity is an essential requirement for

maintaining the high quality of, for example,sterilized foods and modi®ed-atmosphere pack-aged foods. The foremost noticeable packageintegrity problem is probably leaking seals, parti-cularly with ¯exible plastic packages which aremore prone to mechanical damage than traditionalrigid metal packages. A non-destructive leaktesting device is needed which would allowevaluation of every container produced.In recent years, numerous new patents of

devices suitable for the non-destructive testing offood or medical package integrity have beenpublished. Detection of pressure differential iscurrently the most popular method employed for¯exible and semi-rigid packages with a headspace.Evaluation studies of commercial automated non-destructive leak detectors based on detectingpressure differentials revealed that these testmethods were not reliably detecting leakages thatwere proven to be penetrable by harmful microbes.A new automated, non-destructive tracer-gas

leak detection method using hydrogen has beendeveloped and looks very promising (see Figure1). A non-¯ammable gas mixture of not more than5% H2 in nitrogen is ®rst ¯ushed into the packageheadspace just before sealing. The leak-testingequipment basically consists of a vacuum pump/ejector, a test chamber, and an H2 sensor. Thesensor absorbs H2 atoms diffusing into thePalladium layer, which cause a voltage drop inthe electrical ®eld, proportional to the measuredH2 concentration.

Environmental Stress Cracking in Plastics byCharles M. Hansen, Dr. techn. He is a SeniorScientist at the FORCE Institute in Brondby,Denmark.A simple test has been developed for the

cracking tendency of immersed polymer tubeshaving different levels of externally applied,controlled stresses. The test uses a cyclo-ole®niccopolymer. Methyl isobutyl ketone gives rapidcracking of tubes of this polymer at low externalstress while olive oil, for example, is somewhatslower to cause cracking and requires moderateexternal stress. The results reported here con®rmthat the cracking phenemona depend on the sizeand shape of the molecules of the test liquids aswell as their Hansen solubility parameters relativeto those of the polymer.The proposed test uses special stoppers placed

on a top-loader analytical balance. Polymer tubesare pressed onto the stoppers until the balanceshows the given desired force. The tube andstopper are then immersed in a test liquid andobserved for cracking at regular time intervals. Ithas been assumed that the special stoppers areinert in this application.It is hypothesized that the initial stresses present

in plastic tubes can be measured in an alternativeexperiment, directing forces in the opposite direc-

Figure 1. A schematic diagram of a package leak tester usingH2 as a tracer gas. Sensitivity of the H2 sensor> 5� 10ÿ8

Pa m3 s.

Copyright O 1999 John Wiley & Sons, Ltd. 204 Packag. Technol. Sci. 12, 203±205 (1999)

CONFERENCE REPORT

tion of the tube and stopper. The difference in thecracking behaviour between the two test methodswith oppositely directed forces (stresses), can beexpected to re¯ect the initial stresses in the part.The difference should give the initial stress if thecracks appear at the same place when the forcesare applied in opposite directions.

ANovel Surface Treatment Technology for Glassand Other Pharmaceutical and Medical Packa-ging Materials byDanny Connaughton, Ph.D. Heis Business Development Manager at EA Technol-ogy Ltd., Capenhurst, Chester, UK.An experimental programme has been carried

out to coat glass using a procedure which employsa novel plasma technology (see Figure 2). Resultsare presented which indicate that acceptable coat-ings can be successfully applied and hence thetechnology offers a viable, low-cost alternative tothe conventional coating methods which aregenerally adopted in industry.The novel treatment can be viewed as a hybrid

of two types of plasma, each type having usefulattributes but without their respective majordrawbacks. It uniquely combines the advantagesof the atmospheric pressure operation of thermalplasmas with the activating properties of non-equilibrium plasmas, which are important formany surface engineering and ef¯uent treatmentapplications.

Examination by optical microscopy revealed atypical coating thickness of one micron which wasapplied in periods of less than or equal to 20seconds. Coatings were reasonably uniform, withX-ray diffraction analyses con®rming signi®cantrutile content.

Figure 2. Schematic diagram of a novel plasma systemfollowing initiation

Copyright O 1999 John Wiley & Sons, Ltd. 205 Packag. Technol. Sci. 12, 203±205 (1999)

CONFERENCE REPORT