AAPS PharmSciTech

, Volume 9, Issue 2, pp 646–650 | Cite as

Preformulation Considerations for Controlled Release Dosage Forms: Part III. Candidate Form Selection Using Numerical Weighting and Scoring

  • Frank Chrzanowski
Research Article/Themed Issue: Oral/Guest Editors: Stephen A. Howard and Jian-Xin Li Themed Issue: Oral Guest Editors: Stephen A. Howard and Jian-Xin Li


Two numerical methods, Decision Analysis (DA) and Potential Problem Analysis (PPA) are presented as alternative selection methods to the logical method presented in Part I. In DA properties are weighted and outcomes are scored. The weighted scores for each candidate are totaled and final selection is based on the totals. Higher scores indicate better candidates. In PPA potential problems are assigned a seriousness factor and test outcomes are used to define the probability of occurrence. The seriousness-probability products are totaled and forms with minimal scores are preferred. DA and PPA have never been compared to the logical-elimination method. Additional data were available for two forms of McN-5707 to provide complete preformulation data for five candidate forms. Weight and seriousness factors (independent variables) were obtained from a survey of experienced formulators. Scores and probabilities (dependent variables) were provided independently by Preformulation. The rankings of the five candidate forms, best to worst, were similar for all three methods. These results validate the applicability of DA and PPA for candidate form selection. DA and PPA are particularly applicable in cases where there are many candidate forms and where each form has some degree of unfavorable properties.

Key words

candidate form selection decision analysis potential problem analysis 



The author acknowledges the assistance of the Chemical Development Department (preparation of salts and forms), Pharmaceutical Development Department (weighting and seriousness factors) and Physical-Pharmacy Section (Preformulation testing) of The RW Johnson Pharmaceutical Research Institute for their assistance.


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    F. A. Chrzanowski. Preformulation Considerations for Controlled Release Dosage Forms. Part I Candidate Selection. PharmSci Tech. DOI 10.1208/s12249-008-9068-2.

Copyright information

© American Association of Pharmaceutical Scientists 2008

Authors and Affiliations

  1. 1.FA Chrzanowski, Inc.MarltonUSA

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