Saturday, July 15, 2017

How to check the mole balance in your HPLC data and build better kinetic models

We've posted before on the topic of fitting chemical kinetics to HPLC data. Some good experiment planning and design can make this much faster, easier and more informative than a retrospective 'hope for the best' attempt to fit kinetics to experiments coming out of an empirical DOE.

Once the data have been collected from one or two experiments, it's time to check the mole balance. That means checking that your mental model of the chemistry taking place (e.g. A>B>C) and to which your DynoChem model will rigorously adhere, is consistent with the data you have collected. There's a nice exercise in DC Resources to take you through this step by step, using chemistry inspired by a reaction on which Mark Hughes and colleagues of GSK have published and presented.

The exercise starts with HPLC area (not area percent) and after correcting for relative responses leads directly to a new insight into the reaction, even before the first simulation has been run.  When the modeling and experiments are done alongside each other and at the same time, such early insight impacts subsequent experiments and makes them more valuable while reducing their number.

We encourage you to take the exercise to learn this important skill and how to build better, more rigorous and more reliable kinetic models.

Sunday, January 22, 2017

Update 100 to feature enhanced DynoChem vessel mixing and heat transfer utilities

Later this month we will make our 100th round of updates to tools and content in the DynoChem Resources website, so that these are available immediately to all of our users worldwide.  It's appropriate that this 'century' of enhancements is marked by a major release of improved vessel mixing and heat transfer utilities, a cornerstone of scale-up and tech transfer for pharmaceutical companies.

We are grateful to the many users and companies who have contributed requests and ideas for these tools and we have delivered many of these in the 2017 release of the utilities. Ten of the new features are listed below, with a 'shout out' to some customers and great collaborators who led, requested or helped:

Power per unit mass (W/kg) design space for lab reactor;
to produce these results, hundreds of operating conditions are simulated within seconds.
Power per unit mass (W/kg) design space for plant reactor;
to produce these results, hundreds of operating conditions are simulated within seconds.
Design space may be generated with one click on Results tab; 
hundreds of operating conditions are simulated within seconds.
  1. A new Design space feature has been included in several utilities that calculates process results over a user-defined range of impeller speed and liquid volume.  Hundreds of operating conditions are simulated within seconds.  When applied to both Vessel 1 and Vessel 2, this allows identification of a range of operating conditions in each vessel that lead to similar calculated mixing parameters.  Design space buttons are available on the Results worksheets and produce tables and response surface plots. [with thanks to Andrew Derrick, Pfizer] 
  2. We have enhanced Vessel 1 and Vessel 2 Reports, including the user’s name, the date and the version number of the utility.  Reports now also contain individual impeller power numbers, UA intercept and UA(v) where applicable. [with thanks to Roel Hoefnagels, J&J]
  3. We have extended our standard list of impellers, including the two-bladed flat paddle and a marine propeller [with thanks to Ramakanth Chitguppa, Dr Reddys]
  4. Users can now name, include and define multiple custom/user-defined impellers on the Impeller properties tab; vessel database custodians can define a custom impeller list for use across an organization. [with thanks to Ben Cohen and colleagues, BMS]
  5. Users can easily import their organization’s vessel database (including custom impellers) from a file on the network, Intranet or web site.  This means that all users can apply the latest utilities from DynoChem Resources and there is no need for power users / custodians to make separate copies of the utilities and share them for internal use. [with thanks to Dan Caspi, Abbvie]
    One click imports the organization's vessel database and custom impellers
  6. Unbaffled Power number estimates have been enhanced and made a function of Reynolds number.
  7. We have added calculation of an estimate of the maximum power per unit mass generated by impellers in a vessel, based on calculations related to the trailing vortex produced by the blades. [thanks to Ben Cohen, BMS, Andrew Derrick, Pfizer and Richard Grenville, formerly DuPont]
  8. We have added calculation of torque per unit volume, a parameter sometimes used in systems with higher viscosity and by agitator vendors.
  9. We have added the Grenville, Mak and Brown (GMB) correlation as an alternative to Zwietering for solids suspension with axial and mixed flow impellers [with thanks to Aaron Sarafinas, Dow].
    The Grenville Mak and Brown correlation is a new alternative to Zwietering
  10.  Some worksheets are partially protected to prevent unintended edits by users.  There is no password and protection can be removed using Review>Unprotect sheet.

Thursday, December 8, 2016

Congratulations to Dr Marty Johnson of Lilly

Congratulations to Dr Marty Johnson of Lilly, Indianapolis on being this year's winner of AIChE's prize for Outstanding Contribution to Quality by Design for Drug Substance process development and manufacturing.

Marty's nomination was based on a very strong record of innovation and publication related to continuous manufacturing (CM) of active pharmaceutical ingredients and their intermediates, including:
  • being a driving force behind the pharmaceutical industry’s adoption of continuous processing
  • advocating how continuous processing can transform the quality, safety and cost profile of the pharmaceutical manufacturing sector
  • design of equipment platforms that are scalable and able to handle a range of process chemistries and conditions, and
  • more than 25 external publications including innovative ways to run chemistry, equipment characterization, reactor development, process modelling.
Scale-up Systems was delighted to be involved at the AIChE Annual Meeting this year in our continued sponsorship of this prize.  Marty stopped off in San Francisco en route to Asia to collect his award.  Photographs of the awards session will be available here soon. 

Interested in knowing more about CM?  Attend the CM2017 Workshop in Ireland in February 2017.

Friday, September 30, 2016

The 'Doers' in CM meet in Ireland in February 2017

You'll know from previous posts that FDA-AIChE organized a first successful workshop on adoption of CM in Besthesda in February 2016.  That is to be followed just under one year later by a second workshop in Ireland on 22-23 February, 2017.

Like the first workshop, this one will bring together the 'doers' in adopting CM; that is:
  • site leaders and senior managers from pharma manufacturing sites; 
  • leading scientists and engineers driving adoption from HQ and locally; 
  • regulators including reviewers and inspectors and members of emerging technology teams; 
  • and leading investigators from collaborative research centers worldwide.
We will spend two days together hearing the latest updates and progress from industry practitioners, regulators and principal investigators, and in breakout sessions and a tour of a  live operating CM facility for drug substance.  All talks and discussions will address three core themes:
  • Regulatory considerations: expectations for filing and process validation across the product lifecycle (especially how CM differs from batch)   
  • Control strategy, including application of PAT 
  • (Opportunities for) Industry / academic collaboration for shared learning and to address open questions.
Those interested in progressing CM filings, the future of pharmaceutical manufacturing and looking to have an influence or make a contribution in this field will find this workshop valuable and informative.  We look forward to seeing you there.

Online registration and further details of the program will be available shortly.  If you'd like more details in the meantime, contact contact co chairs Mark Barrett (APC) and Joe Hannon (Scale-up Systems).

Tuesday, September 6, 2016

Crystallization Toolbox continues to generate great feedback

Thanks to all the users who worked with us on crystallization projects, especially during 2015, and received training in 2015 and 2016 on the new cooling and antisolvent crystallization toolbox.

For our part, we've been making some of the requested enhancements and the latest version includes additional options for automatically generating cooling and/or addition rate profiles to reach specific process goals.  If you haven't taken a look for a few months, watch this video preview of the quick design sheets and if that whets your appetite, download the toolbox and take the training exercise.

This two-minute video preview shows rapid generation of a solubility curve and quick calculation of potential cooling and/or addition rate profiles and their impact on the rate of crystallization.  [Main steps shown with captions - musical accompaniment by Beethoven :)]

Tuesday, August 30, 2016

Funnel plot helps define control strategy for continuous process

At the FDA-AIChE Continuous Manufacturing (CM) workshop in Bethesda this year, I enjoyed the talk by Ahmad Almaya of Lilly on drug product CM, especially the part introducing 'funnel plots'.

These are a tool to determine for a given CM system and line flow rate the range of disturbance sizes and durations that can be handled before exiting product would drift out of specification. Disturbances could be caused by factors such as equipment failure or changeover in raw material properties; higher amplitudes are harder to deal with.  Disturbance duration reflects how long it takes for such a problem to be detected and the control system response to be put in place; a quick response is obviously best.

In late June, we held a webinar to introduce our latest tool for CM, which calculates the residence time distributions of a sequence of operations (e.g. telescoped reactions and/or workup and isolation for Drug Substance; a sequence of Drug Product operations; or an end to end process).  We simulated the response of the product stream to a series of disturbances and then generated the funnel plot shared below.
Funnel plot for a CM process:
Disturbance amplitude (here labeled 'deviation') on the y-axis and disturbance duration (min) on the x-axis.  Any disturbance in the 'green zone' in this case keeps product in spec while the red zone results in OOS material.
We think this is a very useful representation for use in filings and tech transfers and it's also easy to generate.

Tuesday, June 21, 2016

Links to some good recent Continuous Manufacturing (CM) talks

Unless you've recently returned to earth from a distant planet, you'll be aware of the momentum behind adoption of continuous manufacturing (CM) in pharma and its close relative, Flow Chemistry.  Our team have been active in this area for more than two decades and if you're part of our user community you will know about the relevant equipment, properties and kinetic modeling tools we provide.

Simulation of the response of a CM system to disturbance, using CM synthesis of Ibuprofen as an example.
We've been attending some of the higher profile CM events and also developing additional tools to help manage specific risks.  Here are some links to talks we saw at two events this year that we hope you find useful:

From the ISPE one-day meeting, CONTINUOUS MANUFACTURING – THE FUTURE OF PHARMACEUTICALS?, held in Cork, Ireland in late May:

From the FDA-AIChE Workshop on Adoption of Continuous Manufacturing: held in Bethesda, Maryland at the end of February:

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