BACKGROUND: In view of the high rates of off-label and unlicensed prescribing of drugs in children, the US Food and Drug Administration and the European Union have implemented legislative regulations for the pharmaceutical industry to increase the number of drugs with approved pediatric labeling. However, the extent to which the effects of pharmaceutical technologic aspects of pediatric oral drugs (eg, taste, route and frequency of administration, user instructions) on patient-related outcomes (eg, efficacy, tolerability, preference, adherence) can be based on clinical evidence from the available literature is unknown. OBJECTIVE: This systematic literature review aimed to identify the nature, volume, and quality of comparative studies that have assessed the effects of pharmaceutical technologic aspects of oral pediatric drugs on patient-related outcomes. METHODS: The Cochrane, EMBASE, and MEDLINE databases were searched from their start through December 31, 2009. Studies were eligible for inclusion if they were published in English; included search terms for child, study design, medicine, formulation aspects, dosage form, routes of administration, patient acceptance, adherence, side effects and tolerability, and/or efficacy; reported on > or = 10 children aged 0 to <18 years; and described the effects of > or = 1 of 3 pharmaceutical technologic aspects of an oral pediatric drug (formulation and dosage form; route and frequency of administration; and/or packaging, administration device, and user instruction) on > or = 1 of 6 patient-related outcomes (clinical efficacy, side effects and tolerability, patient preference, patient acceptance, administration errors, and/or adherence). Studies were excluded if they concerned a nonallopathic drug (ie, homeopathic remedy, anthroposophic drug, herbal supplement, or food supplement); related to asthma (because modern asthma treatment protocols strongly favor the use of drug inhalation above oral medication); and/or related to analgesics. The characteristics of each of the included publications were assessed with respect to pharmaceutical technologic aspect studied; patient-related outcomes studied; pharmacotherapeutic indication; year of publication; geographic location; number and age of the included subjects; and sponsorship by industry and/or author affiliation with the pharmaceutical industry. The electronic search was supplemented with a manual search of the cited references. RESULTS: Ninety-four publications were identified as eligible for inclusion. These publications reported on 176 assessments of the effects of > or = 1 pharmaceutical technologic aspect on > or = 1 patient-related outcome. Fifty-five percent of the studies were conducted in children aged 2 or 3 years, and 69% in children aged 4 or 5 years. Forty-three percent of the publications included > or = 100 patients. Fifty-one percent of the studies were conducted in the United States or Canada, and 29% in Europe. Antibacterials for systemic use were the subject of 30% of the included publications. Two of the 94 publications were of appropriate methodologic quality (Jadad score > or = 4). Forty-nine percent of the studies were sponsored by the pharmaceutical industry or were written by > or = 1 author affiliated with the industry. Sixty-eight percent of the included studies had Jadad scores of 0 or 1 (poor quality). The proportion of industry-sponsored or industry-authored studies with a Jadad score > or = 2 or in > or = 100 children was not significantly different from that of non-industry-sponsored or-authored studies. The proportion of industry-sponsored or industry-authored studies conducted in the United States/Canada (48 [51%]) was not significantly different from that of studies conducted elsewhere (46 [49%]). The distribution of technologic aspects assessed in the included studies were formulation and dosage form, 48%; route and frequency of administration, 44%; and packaging, administration device, and user instruction, 8%. Seventy-six assessments included > or = 100 patients. Twenty-one of these assessments addressed patient acceptance or patient preference; 17, clinical efficacy; and 14, side effects and tolerability. CONCLUSIONS: This systematic review identified 94 articles on oral drugs for use in children and adolescents, which reported on a total 176 assessments of the effects of 3 pharmaceutical technologic aspects (formulation and dosage form; route and frequency of administration; and packaging, administration device, and user instruction) on 6 patient-related outcomes (clinical efficacy, side effects and tolerability, patient preference, patient acceptance, administration errors, and adherence). Only 2 of the 94 publications were of appropriate methodologic quality. These results suggest that published clinical evidence to support pharmaceutical development programs is limited.