OBJECTIVES: To conduct a systematic review of RCTs involving topical drugs published in the Archives of Dermatology, Journal of the American Academy of Dermatology and British Journal of Dermatology for correct classification of studies as vehicle versus placebo-controlled.
METHODS: RCTs involving topical drugs published in the Archives of Dermatology, Journal of the American Academy of Dermatology and British Journal of Dermatology from January 1999 to November 2008 were identified through PubMed, supplemented by citation lists from the individual journals' web pages. Only original studies that involved using a topical control or used the term topical "vehicle" or "placebo" were selected. The studies were examined for correct classification as vehicle-controlled, the year of publication, country of origin, sample size, funding source and nature of study center.
RESULTS: Out of 132, 64 (49%) correctly classified their studies as vehicle-controlled. Pharmaceutical-funded studies (55%, P=0.01) were significantly associated with the use of correct classification.
LIMITATIONS: As only three peer-reviewed dermatology journals were studied, findings may not be generalized to other dermatology journals and other types of publications.
CONCLUSION: This systematic review highlights a common pitfall in the reporting of studies of topical dermatology drugs.
RESULTS: CP and EE were found to contain appreciable levels of total phenolic contents (50.6 and 33.41 g kg(-1) as gallic acid equivalent) and total flavonoid contents (205.6 and 244.8 g kg(-1) as rutin equivalent), respectively. DPPH free radical scavenging activity of CP is superior to EE (P < 0.05) showing IC(50) of 77.2 and 995.1 µg mL(-1), respectively. Methicillin-resistant Staphylococcus aureus (MRSA), Bacillus subtilis, Pseudomonas aeruginosa and Salmonella choleraesuis were tested against CP and EE. Only MRSA was the most susceptible bacteria to CP. GC/MS studies resulted in the identification of 79 and 73 compounds in CP and EE, respectively. The most abundant components of EE included β-pinene (24.92%) and 1-dodecene (24.31%). While the major compound in CP were 1,6-octadien-3-ol,3,7-dimethyl (11.55%), cinnamaldehyde (56.15%) and 1-phenyl-propane-2,2-diol diethanoate (11.38%).
CONCLUSION: This study suggests that the essential oils from Cinnamomum pubescens Kochummen and Etlingera elatior could be potentially used as a new source of natural antioxidant and antibacterial in the food and pharmaceutical industries.