Issue link: https://www.e-digitaleditions.com/i/276262
42 March 2014 Tablets & Capsules to 21-years-old scale that an FDA Guidance on pediatric sub-popula- tions recommends [10]. On the other hand, when I was 18 years old, I had long stopped considering myself in need of kids' medicine. For other people in other places, the age of adulthood could be 16 or 21. It's unclear how exactly regulators should define pediatric populations. Naturally, the success of any phar- maceutical product is measured in terms of its therapeutic benefit, but success also depends on its meeting a need and its availability in age-appro- priate formulations. It should also depend on the product's value-for- money. Value is particularly relevant when discussing the elderly popula- tion, an ever-increasing group of patients that is and will continue to strain medical care budgets. One way to reduce that strain is to prevent waste, which is common for a variety of reasons. Some waste occurs when physicians change existing prescrip- tions, rendering the products already in hand of little or no use. Waste can also stem from inappropriate formu- lations, which can lead to non-com- pliance with the prescribed regimen. If that's the case, manufacturers should investigate whether they can improve the formulation. The problems that the elderly face are troubling and worthy of much greater consideration than has been given until very recently. If you're a formulator, consider the challenge of drug delivery to elderly patients as an opportunity. What is the appropriate dosage form? How should it be iden- tified? How can delivery be simpli- fied to improve compliance and thus the therapeutic benefit? To these already difficult-to-answer questions add another: What is the cost of developing drug products that cater to the elderly population and how will they be paid for? Consider for example, the cost of a 5-day supply of dipyridamole. In tablet form, the cost is about $1.80. Delivered in an oral suspension equivalent, it's $66.00. Furthermore, costs can in - crease significantly as people age and prescriptions are added to address co-morbidity. See Figure 1. In pediatric medicine, age groups are clearly defined, and adequately divided into manageable sub-groups. Such is not the case for the elderly, a large and growing population that is considered—erroneously—to be homogeneous. It may make sense to group the elderly population by generation, or at least by decade, instead of the 0- Route of administration, dose level, excipient load, palatability, and stability In my previous contribution to Eye on Excipients, which addressed pedi- atric medicines, I discussed excipient loads, dosage form design, and how to reduce the potential for adverse reac- tions. Some of these same issues arise in the geriatric population and others figure less. For instance, with pediatric medicines, there are many reasons to avoid certain excipients, usually because of their effects on an imma- ture and developing body. For elderly patients—with proportionally greater chances of having life-threatening conditions—the benefits of treatment in many cases outweigh the potential side effects of certain excipients. However, our knowledge of the pharmacology of older patients is con- siderably behind that of other age groups, and co-morbidity issues further complicate the challenge of addressing their needs. The lack of relevant, fit- for-purpose clinical trials has also allowed a large knowledge gap to remain. Even so, some groups of excip- ients can and should be used exten- sively to deliver needed drug products. Taste. Among the excipients and technologies that I believe to be suit- able are ion-exchange resins (vinyl- and divinylbenzene and polystyrene copolymers); betacyclodextrins; and pore-forming barrier coatings, such as ethylcellulose and hydroxypropyl methylcellulose (HPMC). Flavorings are clearly required, but I only accept their general utility as a flavor or a taste-masker in rare cases. That's because the majority of adult doses are larger than pediatric doses and are therefore considerably more difficult to taste-mask. In addition, adult taste preferences differ wildly from those of small children and or juveniles. Tutti-frutti and sticky grape flavors will not win the geriatric com- pliance game. It's rather more likely that the "warmer" flavors (va nilla, apple-cinnamon) will improve compli- ance since they will more likely instill a positive memory and be associated with taking the needed drug products. Mouthfeel and binders. Manni tol and other polyols still have some Figure 1 Co-morbidity increases with age [9] No disease One disease Two or more diseases Age ranges Population by percentage 60s 70s 80s 70 0 10 20 30 40 50 60 40 28 54 26 34 18 15 24 62 l-EOE_40-45_Masters 3/5/14 10:33 AM Page 42