---

ABSTRACT: Introduction & Objective: Acne vulgaris is a common skin disease which affects a large number of adolescents and adults at some time in their life. Several drugs have been used for the treatment of acne vulgaris and recently systemic azithromycin has been tried for its treatment. The aim of this study was to compare the therapeutic efficacy of azithromycin vs. tetracycline in acne vulgaris. Materials & Methods: The present study was a randomized investigator-blind clinical trial, carried out at the outpatient department of Besat Hospital of Sanandaj in 2008. 82 patients were allocated randomly into two groups. Azithromycin 500 mg for 3 consecutive days per week for the first month, then 250 mg/ every other day was prescribed for the first group .The second group received tetracycline 250 mg/6h .The treatments continued for 12 weeks. The therapeutic efficacy of these drugs was assessed on the basis of lesion counting. Data were introduced into SPSS 11.5 software and analyzed by means of independent t- test, Mann-Whitney and chi-square test. Results: The mean number of lesions was not statistically different before treatment in the two groups. There was statistically a significant difference in the mean number of inflammatory papular lesions on the face and back after treatment (p<0.05). However no significant difference was found in comedons lesions in both groups. The percentages of improvement of inflammatory papular lesions on the face and back were 82.3, 63.6 and 80.14 and 58.56 respectively (p<0.05). Conclusion: This study suggested that azithromycin was more effective than tetracycline in treating inflammatory papular lesions of acne vulgaris on the face and back. Azithromycin can be used as an alternative in the treatment of resistant inflammatory papular lesions to tetracycline. Keywords: Azithromycin, Acne Vulgaris, Tetracycline

---

Background & aim: Today, the production of effluents containing medicinal compounds, including tetracyclines, is one of the major threats to the environment and endanger human health. Accordingly, the need for an efficient system to remove these compounds from aquatic environments is felt. Therefore, the aim of this study was to optimize and model the removal of tetracycline antibiotics using TiO2 / N / S nanocatalyst in the presence of visible light in aqueous solutions.
 
 

Methods: In this experimental study conducted in 2019, nanocatalyst was synthesized by sol-gel method and then its characteristics were analyzed using SEM, XRD, EDS and BET analyzes. Secondly, by changing the reaction conditions such as changing the synthesized photocatalyst dose (0.1-2) g/l, antibiotic concentration (1-50) mg/l, reaction time (2-90) minutes and solution pH (2-10) and by visible light irradiation to remove tetracycline from synthetic effluent and the effect of these variables on process performance by response surface method and CCD method and determination of optimal conditions, investigation of reaction kinetics, tetracycline mineralization and photocatalyst performance in real wastewater treatment Was evaluated. Tetracycline was determined by reverse phase high performance liquid chromatography (HPLC). The collected data were analyzed using analysis of variance.

 
Results: The software has proposed a complete quadratic model as the best model, based on ANOVA analysis of variance. The maximum removal efficiency of tetracycline with this process in optimal conditions with a pH of 6 and a time of 56 minutes and a concentration of tetracycline of 13 mg/l was the catalyst value of 1.2 g/l was 77%. The mineralization efficiency of tetracycline antibiotics under optimal conditions was 47% and the kinetic study presented that the data followed the quasi-first-order model well and eliminate the tetracycline process in the wastewater of Imam Sajjad Hospital of Yasuj by 72%.
 
Conclusion: The results indicated that the efficiency of TiO₂/N/S photocatalytic process exposed to visible light radiation in the removal of tetracycline due to lack of by-products as well as mineral end products (carbon dioxide and water) as a desirable process.