The regulatory guidance around Process Analytical Technology is still developing.  There are a number of sources of useful documentation, provided by the FDA, EMEA, ICH and ASTM.

Innovation (and the lack thereof) in the manufacturing of medicines is constrained enormously by the commercial risks associated with deviating from the ‘well trodden paths’ that have been established over the last 40 years. 

The new guidance has been written to provide a framework within which innovation can occur.  As ever it can be a two-edged sword. (For example: 21CFR Part 11 was written to enable pharmaceutical manufacturing to enter the electronic age and you will hear a diversity of opinions on the value of that particular piece of legislation.)

Useful documents produced by the FDA:

Guidance for Industry PAT — A Framework for Innovative Pharmaceutical  Development, Manufacturing, and Quality Assurance.  (Top level document)

Useful documents produced by the ICH (International Conference on Harmonisation):

ICH 8 (R2) Pharmaceutical Development Revisions 2.  (Top level document)

ICH Q9 Quality Risk Management.  (Top level document)

ICH 10 Pharmaceutical Quality System.  (Top level document)

ICH Q2 (R1) Validation of Analytical Procedures: Text and Methodology. ( How-to Document).  Not all of it is always relevant to every PAT assay but it is a well-trusted document.

Useful EMEA documents:

CPMP/QWP/3309/01. Note for Guidance on the Use of Near Infrared Spectroscopy by the Pharmaceutical Industry and the Data Requirements for New Submissions and Variations.

(How-to Document). Not perfect, but mostly right.  Not on any FDA websites.  It was probably written with laboratory-based assays in mind.  Currently under revision.

ASTM standards:

The FDA have, through an organisation known as ASTM International (American Society for Testing and Materials), allowed the Pharmaceutical Industry to write its own consensus standards on PAT and Quality by Design.  On the down side, you have to be a member of ASTM to contribute to the process, and even then access to the individual standards is not free.

E2476 - 09 Standard Guide for Risk Assessment and Risk Control as it Impacts the Design, Development, and Operation of PAT Processes for Pharmaceutical Manufacture.

E2474 - 06 Standard Practice for Pharmaceutical Process Design Utilizing Process Analytical Technology

E2500-07 Standard Guide for Specification, Design, and Verification of Pharmaceutical and Biopharmaceutical Manufacturing Systems and Equipment

E2503-07 Standard Practice for Qualification of Basket and Paddle Dissolution Apparatus

E2537-08 Standard Guide for Application of Continuous Quality Verification to Pharmaceutical and Biopharmaceutical Manufacturing

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