#alcogels

Hand sanitation is very crucial in the prevention of the spread of infectious diseases. Hand sanitizers may help reduce the bioburden of microbes on the skin.  Although hand sanitizers have been shown to be as effective as hand washing in reducing bacterial load, not all hand sanitizers have the same capability to kill / eradicate the growth of different microorganisms. This study evaluated the efficacy of commercially available disinfectant hand sanitizers in the reduction of the bioburden of bacterial hand contamination in twelve (12) volunteer participants. The products tested were:  (1.) ethyl alcohol-based hand gel sanitizers, (2.) isopropyl  alcohol-based hand gel sanitizers, (3.) water-benzalkonium chloride hand sanitizers, and (4.) 2-propanol-benzalkonium chloride disinfectants, that were all accessible in supermarkets. Samples were picked from various retail outlets. Forty-five healthy volunteers participated in the study: 12 for efficacy and 33 for organoleptic studies. The initial procedure required the evaluators to systematically wash their hands with soap and water and air drying. This was followed by contaminating the right and left palms with 5 mL each of  homogenized filthy river water  suspension . The left palm was rinsed with 10 mL sterile distilled water and air dried. The right palm was sanitized with 10 mL of the test disinfectant solution and air dried. Swabs were taken from the palms of the participants after the procedures. The swab obtained from the left palm served as control, while the swab taken from the right palm served as the test sample. The experiment was repeated four more times per participant, and each repetition used a different test sample until all the four types of hand sanitizers were tried out. The numbers of viable bacterial microbes present after application on each palm were used to calculate the efficacy of the hand rub. Efficiency was calculated by comparing the viable microbial load in the left palm (control) versus the microbial load in the right palm (test setup).  Disinfectants with the ability to reduce the microbial load by 50% (equivalent to Log reduction below 3) were considered effective. For the Total Plate Count (TPC) determination, the conventional pour plate technique as described by ISO Method 4833 was followed. The collected swab samples were inoculated into 5 ml of nutrient broth in test tubes followed by serial dilution until 10-3 dilution of each sample. A 0.1 ml of the last dilution was poured into sterile Petri dishes. To each of this broth culture dilution, sterile nutrient agar was dispensed. The agar was allowed to solidify, after thoroughly mixing the poured solution with the agar. Total Plate Counts expressed as colony forming units per mL(cfu/ml), were determined after incubation at 30°C for 72 h. Average TPC was reported per test setup. Results of the study showed that ethyl alcohol sanitizers reduced the microbial load by 43% while the isopropyl alcohol sanitizers reduced the microbial load by 35%. The benzalkonium chloride-based solutions reduced the bacterial load more significantly. Benzalkonium chloride in water sanitizers reduced microbial load to as much as 92% while the benzalkonium chloride in 2-propanol disinfectant solution completely eliminated the microbes ( TPC=0). The antimicrobial potency of commercially available hand sanitizers were revealed in this study. The organoleptic study involved 33 trained evaluators. The participants were asked to apply one of each kind of the test sanitizers daily on their hands for ten times per day for a period of 5 days. Rating scales which included rheology, greasiness, and skin irritability of the test sanitizers were collected at the end of each week. The hand sanitizer samples were tested one at a time per week using a randomized block design program. The preference for gel sanitizers instead of the water based solutions were demonstrated in the results. Alcogels with moisturizers and which were less greasy were the most preferred hand sanitizers by the respondents.