The Role of Excipients in the Microstructure of Topical Semisolid Drug Products

  • Amy Ethier
  • Padam Bansal
  • James Baxter
  • Nigel Langley
  • Norman RichardsonEmail author
  • Amitkumar Mavjibhai Patel
Part of the AAPS Advances in the Pharmaceutical Sciences Series book series (AAPS, volume 36)


The most common pharmaceutical dosage forms for topical delivery of drugs are creams, ointments, and gels, all of which are semisolid in consistency. Attributes that are critical to the effective performance of pharmaceutical semisolids include viscosity, API status, and bioavailability and shelf-life stability. Recent investigations have demonstrated that these critical attributes are driven by the microscale organization of matter (or microstructure) in the semisolid formulation. The microstructure is, in turn, affected by the selection of excipients, amount of excipients, quality of excipients, as well as the processing methods utilized to manufacture the semisolid product. This chapter explores the role of excipients in the microstructure of creams, ointments, and gels, as well as the impact of microstructure on their critical quality attributes and performance.


Excipient Topical Semisolid Microstructure Critical quality attributes 


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Copyright information

© AAPS (American Association of Pharmaceutical Scientists) 2019

Authors and Affiliations

  • Amy Ethier
    • 1
  • Padam Bansal
    • 2
  • James Baxter
    • 3
  • Nigel Langley
    • 1
  • Norman Richardson
    • 1
    Email author
  • Amitkumar Mavjibhai Patel
    • 2
  1. 1.BASF Pharma SolutionsTarrytownUSA
  2. 2.Amneal PharmaceuticalsPiscatawayUSA
  3. 3.LubrizolClevelandUSA

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