Tastemasking of solid dosage forms and liquid drugs is a challenge for pharmaceutical manufacturers. Most APIs are unpleasant or harsh tasting, which can lead to patient noncompliance. This challenge affects all age groups, but is specifically problematic for pediatric patients. Implementing tastemasking programs into the drug-manufacturing process is crucial to avoid losses due to noncompliance. Pharmaceutical manufacturers are faced with challenges in life-cycle management, cost control, global regulations, and patent protection. In a Q&A, Pharmaceutical Technology examines excipient selection and functionality in tastemasking applications.

In a webcast, Pharmaceutical Technology examined formulation development in product life-cycle management, including specialized formulations such as pediatric formulations, and related technical issues in excipient selection and functionality, including tastemasking and moisture protection, to develop an orally palatable product (1). Participating in the webcast were: Avinash Thombre, PhD, research fellow, pharmaceutical sciences with Pfizer Global Research and Development, who discussed life-cycle management and new dosage-form options; Karen C. Thompson, PhD, distinguished senior investigator, pharmaceutical sciences at Merck & Co., who discussed insight into pediatric formulations and related dosage forms; and Nigel Langley, PhD, MBA, head of North American technical sales, Pharma Ingredients & Services, BASF, who discussed novel tastemasking excipient solutions. For a perspective on excipient selection and functionality in tastemasking applications, Patricia Van Arnum, executive editor of Pharmaceutical Technology and moderator of the webcast further discussed these issues with BASF's Langley.

The dialogue was initiated following the launch by BASF of an excipient, Kollicoat Smartseal 30 D, an aqueous dispersion of a film-forming polymer with tastemasking and moisture-barrier applications for solid dosage forms. The product is a new coating polymer and is supplied as a 30% dispersion in water. From a product-characteristic perspective, the excipient is highly impermeable to water vapor, which helps preserve the potency of sensitive active ingredients. The polymer is stable in saliva and specifically soluble in gastric juice. These properties allow for effective protection from unpleasant taste in the patient's mouth and rapid release and onset of active-ingredient action in the stomach.

Excipient properties in tastemasking

PharmTech: What characteristics does an excipient need to have to provide tastemasking?

Langley: The material has to be stable at pH 6.8 to 7.2, so you do not get any of the bitter drug released in the saliva. In addition, the drug has to, upon entering the stomach, be rapidly released at a low pH. We are basically looking for a reversed enteric polymer to provide that functionality. With respect to Kollicoat Smartseal 30 D, specifically, the polymer is insoluble at basic and neutral pH value and has very low vapor permeability, which is characterized by the structure—primarily, the two ethyl groups that are attached to the nitrogen moiety and the polymer itself is the methyl methacrylate diethylaminoethyl methacrylate copolymer. It is very insoluble at pH neutral values as well as basic pH. It forms a salt at pH values below 5.5, so the polymer dissolves quickly in the stomach releasing the drug.