Tableting Process Uses Dry Gelatin, Eliminates Preprocessing Steps

July 1, 2004
Minh Van Nguyen, a pharmaceutical chemist based in Anaheim, California, has developed "simple compression," a new method for preparing drug tablets, which was showcased at INPEX, the inventor exposition held in Pittsburgh last month. The technology would eliminate the need for preprocessing steps, such as granulation, spheronization, spray drying or crystallization, he says, allowing tablets to be compressed directly from powdered materials. It would cut tablet manufacturing costs by an average of 75%.The impetus for developing this process was the need for less-expensive manufacturing technologies in the inventor's native country, Vietnam. For the past 20 years, Mr. Nguyen has worked in quality control, most recently as vice-president of quality control for a pharmaceutical firm in Vista, Calif. "Tableting processes are too complex and some of them, such as wet granulation, are so dirty that they require a significant amount of cleanup time," he says.Dry gelatin is the key to the process, Nguyen says, since its binding, cohesive and hydrophilic properties allow it to function as diluent, binder and disintegrator. Only three steps: weighing, mixing and compression, are involved.Although dry processing might, intuitively, seem to lead to a brittle product, Nguyen claims that the process results in a product with friability of less than 0.5%. In general, he says, gelatin grades with higher bloom values yield harder tablets with lower friability.Drug manufacturers had worked with gelatin in solution as a tableting agent years ago, but abandoned it, in most cases, when alternatives were found. Gelatin's performance drawbacks in solution form may have kept more manufacturers from exploring use of solid material, Nguyen says.The simple compression process can be customized, its inventor claims, so that disintegration takes anywhere from under a minute to several days. Unlike wet granulation, Nguyen says, simple compression does not expose active ingredients or excipients to moisture or heat. It also avoids the high compaction pressures found in dry granulation, he says, and, since they contain less excipient, tablets are smaller than those produced by direct compression. In addition, the inventor claims, the resulting tablets are stable, and can endure packing, shipping and storage.Over the past five years, Nguyen has used standard equipment, performing extensive integrity and stability tests, to evaluate use of the simple compression process for a wide variety of products, from prescription formulas to over-the-counter drugs and neutraceuticals. He is currently offering the technology for license, and has just published a book on the subject. For more information, email him at [email protected].