Ideally, one should purchase over-the-counter (OTC) products with a reliable hechsher. Star-K certified products contain only kosher approved ingredients. A product containing a trace of a nonkosher ingredient (even if it is batel bshishim) cannot be certified Star-K. Similarly, all certified products are manufactured without any keilim concerns.
Unfortunately, very few OTC products are kosher certified, and kosher consumers who require such products are often confronted with shailos (questions). The Star-K reviewed ingredients used in hundreds of OTC products manufactured by many of the major pharmaceutical companies including Bayer, Bristol-Myers Squibb, Glaxosmithkline, McNeil, Novartis, Pfizer, Procter & Gamble, Purdue Frederick, Schering-Plough, and Wyeth.
In compiling a list of “approved” medications for use by one who is a choleh (ill) or has a maychush (discomfort) the following halachic guidelines were used:
Equipment – If all ingredients are kosher, there is no concern that the medicinal ingredients were produced on treif equipment (see Yoreh Deah 122:6).
If a non-kosher ingredient is added by the company and is less than 1/60 of the product (by volume), the non-kosher is batel b’shishim and the product may be taken. Ingredients that are commonly batel include the following:
Stearates, often derived from animal sources, are used in tablets as a lubricant. However, there is no kashrus concern as the stearates are usually less than one sixtieth. (Even if they are more than one sixtieth, they are batel b’rov because they are tasteless.) The stearates also may be kosher as this ingredient can be derived from vegetable sources.
Flavors – Although food products with natural and/or artificial flavors must have a reliable hechsher, medications are permitted, even if they contain flavors. One can assume the non-kosher flavor component is batel. (In this case, for various reasons, kol davar she’avidi l’taama afilu b’elef lo batel, does not apply.)
Products without a reliable certification containing the following ingredients, were not included on this list (unless we were able to confirm that they are batel): carmine, emulsifiers, gelatin, glycerin, monoglycerides, neutral soaps, oleic acid, polysorbates, sorbitan monolaurate, triacetin.
It should be noted that one who’s life is or may be in danger should use any non-kosher medication if an equally effective kosher medicine is not readily available.