A lot of pharmaceutical products, cosmetics and food products are emulsions & gels. Regarding the production of pharmaceutical semi-solid preparations, the common GMP (Good Manufacturing Practice) concepts of validation and qualification have to be applied (i.e. EU GMP guidelines including Annex 9 and 15). Semi-solid products have some characteristics that are different compared to other dosage forms (e.g. solid oral dosage forms). Due to the intrinsic effect of the vehicle and the influence of the formulation on the release of active ingredients (and the subsequent absorption), the final formulation (including packaging) should be defined early in the pharmaceutical development process. Comprehensive analytical, microbiological and stability testing contributes to that.
In 2018, the EMA published the draft Guideline on quality and equivalence of topical products
. The guideline relates to locally applied and locally acting medicinal products for cutaneous use. Specific guidance is provided:
- On the quality of topical products not covered by other guidelines.
- On equivalence testing of topical products in lieu of therapeutic equivalence clinical trials.
Additionally, important tools for the biopharmaceutical characterization of drug release are contained in the United States Pharmacopeia (USP) Chapter <1724> “Semisolid Drug Products – Performance Tests“
. A reference to <1724> is made in USP 〈3〉 “Topical and Transdermal Drug Products - Product Quality Tests”
. In a draft version of chapter <1724>, published in PF 48(3), the scope has been expanded to include in vitro release test (IVRT) as well as in vitro permeation test (IVPT) methods, with discussions on experimental design, method development, and validation.
Furthermore, rheology plays a significant role in the determination of a formulation’s flow properties (and for the characterization of semi-solid raw materials, like for example petrolatum, lanolin), during development, in-process-control (IPC), final end-product testing & release as well as in stability testing. The knowledge of rheological properties is essential for the production and filling of semi-solid preparations. Moving forward, the USP introduced two new USP Chapters <915> “Measurement of Structural Strength of Semisolids by Penetrometry”
and <1912> “Measurement of Hardness of Semisolids”
(an updated title was proposed in PF 48(3) to better describe the content of the chapter: Measurement of Yield Stress) regarding the characterization of viscoelastic properties of semi-solid preparations.
These and other relevant topics will be presented and discussed in this Live Online Training.