Study On Rapid Test Method Of Quaternary Ammonium Disinfectant And Its Microbicide Gel

Quaternary Ammonium disinfectant has the advantages of low germicidal concentration, colorlessness, odorlessness, non-irritability, low toxicity and safety. It has been hailed as ideal disinfectant at the beginning and extensively applied in medical and health, food and daily chemical industry. At home and abroad, the majority of chemical analysises are to test its content and nearly no method for quaternary ammonium salt identification, which is inconvenient to do daily monitor and test at disinfection field. On the basis of existing chemical analysis method, we study on the rapid and simple test method of quaternary ammonium disinfectant by comparing and selecting.Microbicide is one of the important methods to prevent Sexually transmitted disease (STD), especially virosis such as AIDS. Microbicide is able to meet women's need of prevention. It can be localized in the vagina and cervix and kill or inhibit viral and bacterial pathogens including HIV, thus effectively preventing STD transmission. So we develop a new microbicide of gel mode, basing on quaternary ammonium disinfectant's character of safe, effective and its small mucosal irritation to the skin, which is a handsome, stable, comfortable to use, and no pollution to clothing.The issue was divided into two parts. Part I: First, indicator will be selected basing on the experiment of mixing quaternary ammonium salt with indicators. Then we observe the interference factors of the chemical reaction of indicator and quaternary ammonium. At last according to practical application test, we confirm whether it's effective or not. Part II: First, according to co-operation test, gel matrix will be selected. And then, using microbe killing test, stability test and pH value test to study and evaluate the comprehensive performance. Major findings are summarized as follows: 1 Research on rapid analysis of quaternary ammonium disinfectant⑴The results of mixing quaternary ammonium salt with seven different chemical reagents show as below: white deposition is generated when mixing quaternary ammonium salt with sodium tetraphenylborion; yellow deposition when mixing with potassium ferricyanide; the color of solution will become peachblow when mixing with bromeosin; yellow deposition which is dissolved in dilute nitric acid is generated when mix with potassium dichromate; the color will become yellow when mixing with thymol blue-methylene blue; the colorless organic layer will be changed into yellow when mixing with chloroform; the colorless organic layer will be changed into blue when mixing with dimidium bromide-acid blue or ethidium bromide-acid blue. Above reagents can react with quaternary ammonium salts significantly, which can be used as the indicator of qualitative identifying analysis.⑵We mix glutaraldehyde, chlorhexidine acetate, ethanol, isopropyl alcohol which may affect the color with quaternary ammonium salt respectively, then use sodium tetraphenylborion, potassium ferricyanide, bromeosin, potassium chromate - dilute nitric acid, thymol blue - methylene blue, ethidium bromide- acid blue to do the test. The results show that: sodium tetraphenylborion, potassium ferricyanide and bromeosin can react with chlorhexidine acetate and the phenomenon is the same as the reaction with quaternary ammonium salt, which interferes with the identification of the quaternary ammonium salt; the result is negative when potassium dichromate - dilute nitric acid react with quaternary ammonium alcohol solution by the impact of ethanol and isopropyl alcohol; only thymol blue - methylene blue and ethidium bromide- Acid Blue is not interfered.⑶The result of experiment that using quaternary ammonium salt of different concentration react with thymol blue - methylene blue and ethidium bromide- acid blue shows that the color of the solution gradually changes from positive result to negative result. The sensitivity of thymol blue - methylene blue method 1 is 0.01%. The sensitivity of thymol blue - methylene blue method 2 and ethidium bromide- acid blue method is 0.001%. The experiments that mixing above four interferences with quaternary ammonium salt of different concentrations (1%, 0.1%, 0.05%, and 0.01%) shows that: the result of containing quaternary ammonium salt is positive, while the result of excluding quaternary ammonium salt is non-positive. According to the above methods, 10 disinfectant products chose from market are identified respectively. The result of the three methods of identifying is exactly the same with the actual result. 2 Research on quaternary ammonium germicidal gel⑴The screen result of five gel matrix through chemical reaction test screen shows: the gel of HPMC has a transparent appearance and feels comfortable; carbomer and sodium alginate can react with benzalkonium bromide and a white deposition can be generated. Because the two matrixes are anionic compounds which can react with the cation of quaternary ammonium salt, and gel formed by reacting with sodium alginate is yellow; PVA and carboxymethyl cellulose can not react with benzalkonium bromide but they're poor in molding and visco-hand.⑵We study the gel of HPMC containing benzalkonium bromide and octoxinol of different concentration to know that the viscosity of gel also increases as the concentration of HPMC increases. The viscosity of 0.5% concentration is more appropriate. Considered the shape, feel, viscosity, and other factors, the final formula is 0.2% benzalkonium bromide, 0.5% HPMC, 0.5% octoxinol, 2% glycerol.⑶After the original solution work on the Staphylococcus aureus and Pseudomonas aeruginosa for 0.5 min, the average logarithmic value of the killing reached 7.3940 and 7.4510 respectively, while working on Candida albicans for five minutes, it reached 5.1770.The correlation between Candida albicans survival logarithmic value and work time of gel is: for Candida albicans, Y = 5.6250-0.5538X (r = 0.9011, P = 0.0368). The time of quaternary ammonium gel killing 90 percent of Candida albicans is 1.8057 min (D value).⑷The results of killing microbe by different concentration are showed as below. After 1:1 diluted solution work on the Staphylococcus aureus and Pseudomonas aeruginosa for 0.5 min, the average logarithmic value of the killing reached 7.3757 and 7.2613 respectively. After 1:10 diluted solution work on the Staphylococcus aureus for 0.5 min, the average logarithmic value of the killing reached 5.0537, while 7.3879 after 3 min. After this solution work on Pseudomonas aeruginosa for 1 min, the average logarithmic value of the killing reached 5.7433, while 7.3721 after 3 min.The coefficient of the concentration is 0.7781.⑸The results of killing microbe by different temperature are showed as below. Under the experimental condition of 10℃to 35℃, the average logarithmic value of the killing of the original solution of quaternary ammonium gel working on Candida albicans increases as the temperature rises. At different temperatures, the correlations between the survival logarithmic value of Candida albicans and working time of disinfectant are: at 10℃,Y = 6.1772-0.3901X ( r = -0.9000, P = 0.037 ), D = 2.5634min; at 20℃,Y = 5.6250-0.5538X ( r =-0.9011, P = 0.0368 ), D = 1.8057 min; at 30℃,Y = 6.5786-1.2222X ( r =-0.9659, P = 0.0341 ), D = 0.8182 min; at 35℃,Y = 6.3903-1.2482X ( r =-0.9523, P = 0.0477 ), D = 0.8011 min. The average temperature coefficient Q10 is 1.8133.⑹At the same working time, the average logarithmic value of the killing of the original solution of quaternary ammonium gel working on Candida albicans decreases as the concentration of fetal calf serum increases. At different concentrations of fetal calf serum, the correlations between the survival logarithmic value of Candida albicans and working time of disinfectant are: when the concentration is 0, Y = 4.2897-0.3512X ( r =-0.9561, P = 0.0439); when the concentration is 25%, Y = 5.1351-0.4255X ( r =-0.9607, P = 0.0393), when the concentration is 50%, Y =5.1404-0.4162X ( r =-0.9582, P = 0.0418).⑺The stability of recipe can be measured by the accelerated stability test. After the gel is stored under the temperature of 54℃for 14 days, the final results showed the decline rate of benzalkonium bromide concentration is only 0.05%, the storage period can be set for one year.