[Frequency of contact dermatitis in patients with chronic dermatitis referring to dermatology clinics in Kerman]

Allergic and irritant compounds are frequent in nature, and the environmental allergic factors which can induce or exacerbate eczema are different and often unknown in different areas. The aim of this study was to determine the frequency of contact dermatitis in patients with chronic dermatitis referring to dermatology clinics in Kerman. In this descriptive study, standard patch test containing 24 allergens was done for 156 cases [56 males and 69 females] with confirmed chronic dermatitis who had been referred to Afzalipoor Hospital Dermatology Clinics. Evaluation of the results was done for every case 24, 48 and 72 hours after application of the patch test. In whole, 153 positive patch tests were seen in 66 [52.8%] cases of 125 patients who had been examined. The most common allergic agent was nickel sulfate detected in 20 [13.1%] patients [17 females and 3 males]. The hypersensitivity reaction to this agent was significantly more common in females than males [P<0.05]. Potassium dichromate with frequency of 11.1% [12 males and 5 females] was the second common allergic agent and males showed significantly more positive reaction to this agent than females [p<0.05]. There was no statistically significant difference according to the age and sex between groups with positive and negative patch test results [P>0.05]. As the causative agents of contact dermatitis are different in various areas, by doing patch test in each area the allergic agents can be detected for more appropriate preventive measures and treatment strategies. In this study, the first and second common allergens were respectively Nickel and Chrome compounds. Thiorum, Cobalt, benzocaine and theazolin compounds were in the third rank

[Formulation of erytromycine and tretinoin in a topical gel base]

Acne vulgaris is a chronic and prevalent usually self-limited disorder. Topical medication is the main route for acne therapy. In this disorder, the most widely used topical preparations are antibiotics such as Erythromycin and keratolytic agents such as Tretinoin. Excellent results with minimal side effects may be achieved by a fixed combination of Tretinoin and Erythromycin. This combination therapy increases efficacy and a faster response in the treatment of acne may be achieved. The purpose of this work was to assess a suitable formulation of Erythromycin and Tretinoin in a topical gel base. UV spectrophotometer analysis was chosen for Erythromycin and Tretinoin assay. This method was adapted to assay Erythromycin and Tretinoin in their combination. The proposed method for Erythromycin was the formation of a complex with O- nitro benzaldehyde, in glacial acetic acid and in the presence of hydrochloric acid, which manifested maximum absorbance at 486nm. For the measurement of Tretinoin, the absorption peak at 355nm in acidic Ethanol-Water-Iso Propyl alcohol [IPA] mixture was suitable. In order to formulate the Tretinoin and Erythromycin in a gel base, gelling agents, plasticizers, solvents, cosolvents such as Carbopol, HPC, HPMC, Ethanol, Propylene Glycol [PG], Isopropyl Alcohol [IPA] and Water have been used. By using tertiary diagrams, the most proportionate percentage of gel constituents have been determined. The formulations have been controlled for rheological, organoleptic properties and physical and chemical stability under several conditions [4, 25, 40 degree C]. The release of drugs from the gels was studied using Franz diffusion cell and the best formulations were chosen. Drug release rates followed Higuchi's law. The results indicated that Erythromycin and Tretinoin could be formulated in a gel base with a suitable release profile and presented to pharmaceutical market