Oral administration of medication to cats can be a challenge for many pet owners, and owner compliance is a concern for veterinarians when treatment for cats relies on orally administered drugs. Traditionally, medications intended for oral administration in cats are manufactured into tablets, capsules, or solutions in oil or water. There are many opinions regarding the formulation that is easiest to administer to cats, but to the authors' knowledge, no scientific studies have indicated the superiority of any vehicle formulation over any other.
In addition to anecdotal concerns about pill administration in cats, studies1–3 have revealed that pills and capsules administered to cats can become trapped in the esophagus,1,2 where the medications can cause damage to the mucosa.3 Although it is compelling to consider alternative formulations for the delivery of oral medication in this species, increased difficulty of administration could result in reduced owner compliance, and this concern would have to be considered carefully against the decreased risk of esophageal injury.
In the few studies4,5 that have been published on the subject, owner compliance has been reported to range from 20% to 80%. The investigators of those studies reported frequent owner complaints that administration of pills to cats was physically challenging or caused cats to avoid interaction with the owners. Any formulation that would increase the ease of medication administration would be likely to increase owner compliance. An objective evaluation of owners' preferences for various formulations and their perceptions of formulation acceptability to their cats would provide valuable information to veterinarians prescribing medications and to the pharmaceutical industry during development of new drugs.
A limited number of drugs for human use (eg, laxatives such as sennosides,a antihistamines such as diphenhydramine HCl,b topical anesthetics such as benzocaine,c and antifoaming medications such as simethiconed) have been made available for oral administration in the form of a dissolving thin film strip, similar to strips used as breath fresheners.6,7 These strips may be designed to facilitate absorption in the oral mucosa or gastrointestinal tract or to have topical effects, depending on the intended result.7 Use of the film strip formulation has not been reported in veterinary medicine, and therefore to the authors' knowledge, no information is available on the ease of administration to cats or how well it is tolerated in this species. The study reported here was designed to compare 3 formulations that could potentially improve client compliance in oral administration of medications to cats, which could enhance the development of future drugs. It was not designed to evaluate the formulation technology. We tested the hypothesis that no difference would be detected in ease of administration for owners or perceived acceptability to cats between MCT oil, film strip, and gelatin capsule formulations.
Least squares mean
Medium chain triglyceride
Visual analogue scale
Pedia-lax quick dissolve strips, CB Fleet Co Inc, Lynchburg, Va.
Benadryl allergy quick dissolve strips, McNeil-PPC Inc, Parsippany, NJ.
Ora film, Apothecus Pharmaceutical Corp, Oyster Bay, NY.
Gas-X thin strips, Novartis Consumer Health, Parsippany, NJ.
Captex 355 MCT oil, Abitec Corp, Janesville, Wis.
20 × 10-mm dissolving thin film strip, provided by Dennis Huczek, Pharmaceutical Sciences, Pfizer Animal Health, Kalamazoo, Mich.
No. 4 capsule, 14.3 mm, Capsugel, Greenville, SC.
Pet Piller, H-BAR-S Manufacturing, Boerne, Tex.
SAS, version 9, SAS Institute Inc, Cary, NC.
Westfall DS, Twedt DC, Steyn PF, et al. Evaluation of esophageal transit of tablets and capsules in 30 cats. J Vet Intern Med 2001;15:467–470.
Graham JP, Lipman AH, Newell SM, et al. Esophageal transit of capsules in clinically normal cats. Am J Vet Res 2000;61:655–657.
Beatty JA, Swift N, Foster DJ, et al. Suspected clindamycin-associated oesophageal injury in cats: five cases. J Feline Med Surg 2006;8:412–419.
da Silva CM, Colombo AV, do Souto RM, et al. In vivo evaluation of the effect of essential oil-containing oral strips on salivary bacteria using the checkerboard method. J Feline Med Surg 2005;16:38–43.
Barnhart SD. Thin film oral dosage forms. In: Roberts MS, Rathbone MJ, Hadgraft J, eds. Modified release drug delivery systems. 2nd ed. London: Informa Health Care, 2007;209–216.
Bellows J. Periodontal disease. In: Smile book IV: small animal dental anatomy, pathology and charting. New York: Pfizer Animal Health, 2004;17–19.
Wewers ME, Lowe NK. A critical review of visual analogue scales in the measurement of clinical phenomena. Res Nurs Health 1990;13:227–236.