processing technology 39
which includes the universities of Leeds, Heriot-Watt and measurement of solution supersaturation associated
Newcastle, along with ten key industrial partners. It is with the batch cooling crystallisation of LGA at both
primarily concerned with optimal design of batch reactors 500 ml and 20 l scale sizes. This is assessed via ATR-FTIR
using in-process measurement and advanced modelling spectroscopy.
techniques, and works in measurement and modelling A partial least-squares chemometric calibration
across the length scales relevant to pharmaceutical and model was developed for the online prediction of LGA
organic fine chemical production. concentration from measured FTIR absorbance spectra
This is the latest in a raft of new quality by design overcoming some significant challenges related to the low
(QBD) tools being developed for the pharmaceutical sensitivity of LGA in the mid-IR frequency range, its low
manufacturing sector as part of a drive for increased solubility in water, and its complex speciation chemistry.
understanding of drug processing fundamentals. According to the authors, the solubility data of LGA
“By developing tools to increase knowledge about, in water over the temperature range from 40-80˚C, using
and monitor, batch process systems, we’re providing ATR-FTIR, reveals excellent agreement with that obtained
practical solutions to problems faced by industry on a both from using a gravimetric method and literature
daily basis,” says Mahmud. “This sort of technological data. The metastable zone width determined using the
approach to manufacture will help reduce waste – and turbidimetric methods as a function of heating/cooling
therefore costs – and could have a significant role to play rates and solute concentration is found to increase with
in increasing the competitiveness of the pharmaceutical increasing cooling rate while it decreases with increasing
sector.” solution concentration.
Monitoring online crystallisation via both spontaneous
Monitoring supersaturation
and seeded in 500 mL and 20 L crystallisers reveals good
The Leeds research is published in a paper entitled “In concentration predictions for seeded crystallisation, while
situ Measurement of Solution Concentration during the fouling of the ATR crystal prevents its routine use for
Batch Cooling Crystallisation of L-Glutamic Acid using unseeded crystallisation studies.
ATR-FTIR Spectroscopy Coupled with Chemometrics” and Higher supersaturation levels are found for the larger
has been published online in Crystal Growth & Design. crystalliser scale-size, consistent with enhancement of
In it, the authors give details of the in situ secondary nucleation at the smaller scale-size. u
'silver bullet' kills contaminating bugs in the lab
a
two-month environmental study the tvc of bacteria contaminating the be essential, permanent antimicrobial
has shown that silver-based biocote-treated equipment, compared surfaces of instruments represent a
biocote antimicrobial protection, an with untreated control items in the same powerful weapon against the hazards of
integral feature of all stuart benchtop environment. lab-acquired infection and contamination of
laboratory equipment, reduces bacterial according to rob skehens, marketing precious experimental or test samples. this
contamination of instrument surfaces by Director, bibby scientific: "this important is particularly true for surfaces subjected
over 96 per cent. study suggests that biocote antimicrobial to physical contact with reagents, or
Details of the study, carried out protection has a vital role to play, repeated hand contact by multiple users."
at the university of birmingham in a complementing established glp and gmp laboratory evidence suggests that
laboratory conducting research for biocote technology, in the form of
cancer research uk, are published silver ions, disrupts the bacterial
by bibby scientific. bacterial surface cell membrane function and causes
contamination of six biocote-treated denaturing of vital enzymes within
stuart instruments, such as hotplate the cell, leading to rapid cell death.
stirrers and a mixer, was compared silver ions are slowly released from an
with untreated instruments in the inorganic matrix via an ion exchange
same laboratory. all items included mechanism, maintaining an effective
in the study had been in routine use concentration on or near the surface
for around 18 months. swabs from of the material. active throughout the
touchpads, switches, casings etc. useful life of each instrument, biocote
were collected fortnightly for two kills a wide range of bacteria and
months and total viable counts (tvc) fungi, including mrsa, e. coli,
were obtained after inoculation and legionella, staphylococcus aureus
incubation of plate count agar. protocols, in ensuring that laboratory and aspergillus niger. u
results were, according to bibby environments comply with the highest
scientific, dramatic: there was a mean health and safety standards. While surface For more information, visit
reduction in excess of 96 per cent in disinfection in the laboratory will always www.bibby-scientific.com
www.scientistlive.com
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