Extractability testing diffusion studies

Diffusive samplers have also been developed to determine SVOCs but there have been relatively few studies to date. An example is the passive flux sampler developed by Fujii et al. (2003) to determine the rate of emission of phthalate esters from materials. The sampler consisted of a circular metal disc containing activated carbon particles held within an inert matrix of PTFE. The sampler was placed on the material under test giving a diffusion length of 0.5 or 2 mm depending upon the design and adsorbed phthalate esters were extracted from the sampler with toluene and determined by GC-MS. 

GC-MS can be used for determination of A-trifluoroacetyl derivatives of PAA. In cases when various analytes are present in the sample, MS detection in the scan mode instead of the SIM mode allows further identification by display of the full MS. A study was carried out of water spiked with aniline (la), toluene-2,4-diamine (2e), toluene-2,6-diamine (2f), 4,4/-diaminodiphenylmethane (5a), 4,4/-oxydianiline (6a), 3,3 -dimethylbenzidine (7d), 1,5-diaminonaphthalene and 1,3-phenylenediamine (lk), which underwent SPAD to the corresponding trifluoroacetamides (Section III.B.l). The LOD were in the 0.1 to 0.4 ftgL-1 range, with RSD from 4 to 17%. The method was used for testing the diffusion of PAA into food (simulated by water) which was in contact with laminated flexible food packaging materials. Detectable extracted levels were found for 2e, 2f and 5a68. 

Tamarind fruits are reported to have anti-fungal and anti-bacterial properties (Ray and Majumdar, 1976, Guerin and Reveillere, 1984, Bibitha et al, 2002, Metwali, 2003, and John et al, 2004, all cited in (5)). According to Al-Fatimi and collaborators 11), in an agar diffusion assay, extracts from T. indica flowers showed antibacterial activity against four bacteria tested Staphylococcus aureus, Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosa). Antimicrobial activity of T. indica study has been attributed to lupeol (Ali et al, 1998, cited in 11)). 

A device containing a drug substance reservoir or matrix from which drug substance diffuses should be tested for total drug substance content, degradation products, extractables, in vitro drug release rate, and as appropriate, microbial burden or sterility. The stability protocol should include studies at 37° or 40°C over a sufficient period of time to simulate the in vivo use of the drug delivery device. 

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