The functional evaluation of binders in the wet granulation process

Carl William Symecko, University of Rhode Island


The USP/NF sets the standards and maintains monographs which outline the methods to assess the chemical purity of drugs and pharmaceutical excipients. These methods, however complete, do not address the physicochemical properties of excipients which are critical to their performance in wet granulated systems. Pharmaceutical binders are included into wet granulated systems to promote bond formation during the granulation and compaction steps of this tablet manufacturing process. This investigation outlines methods used to evaluate the functionality of pharmaceutical binders in wet granulated systems by evaluating their influence on the granulation, compaction of that granulation and the properties of the resultant end-products, tablets. Binders from natural (Starch NF), semisynthetic (Maltodextrins and Pregelatinized Starches), and synthetic (Povidone), sources were evaluated to characterize their functionality in model wet granulated systems. The Maltodexterin and the Povidone investigated were identified to produce systems with different responses to compaction force in terms of tablet hardness. Also, when the critical processing variable of tablet press speed was investigated, the granules' ability to fragment was identified as critical to inter-particulate bond formation at low speeds and low compaction forces, however at high forces, the systems' ability to deform plasticly was identified and this was dependent on press speed. Four different brands of pregelatinized starch, National 1551$\circler$, Starch 1500$\circler$, Lycatab$\sp{\rm TM}$PGS, and Pregeflo$\sp{\rm TM}$M, were investigated to identify limitations of the current USP/NF monograph. In evaluating the effect of these compounds on dissolution performance, a significant difference was observed between the starches which meet USP/NF standards for purity, and the brand that did not. Also, a difference was observed between the partial, and completely pregelatinized systems. In the case of the pregelatinized starches, chemical purity as outlined in the current monograph, as well as degree of pregelatinization (partial or full), would be complete in their characterization. The methods outlined in this investigation may serve as a model for the investigation into the functionality of other excipients used in the manufacture of tablets by the process of wet granulation. ^

Subject Area

Health Sciences, Pharmacy

Recommended Citation

Carl William Symecko, "The functional evaluation of binders in the wet granulation process" (1994). Dissertations and Master's Theses (Campus Access). Paper AAI9513253.