Test protimikrobne učinkovitosti izbranih snovi naravnega izvora v dermalni formulaciji z uporabo mikroorganizmov Pseudomonas aeruginosa in Aspergillus brasiliensis

Oštir, Andraž (author), Kočevar Glavač, Nina (mentor), Ravnikar, Matjaž (co-mentor)

Mikrobiološka kakovost kozmetičnih izdelkov postaja v zadnjih letih, z razcvetom naravne kozmetike, eno vidnejših področij razvoja in inovacij v kozmetični industriji. Mikrobiološko kvarjenje vodi v razpad izdelka, prisotnost patogenov pa predstavlja potencialno zdravstveno tveganje. Za zagotavljanje uporabnikove varnosti in zaščite kozmetičnega izdelka pred mikrobiološko kontaminacijo najpogosteje uporabljamo konzervanse. Rezultati raziskav glede varnosti določenih sinteznih konzervansov so privedle kozmetično industrijo do iskanja njihovih alternativ naravnega izvora. Tako vzbuja veliko zanimanja razvoj kozmetičnih izdelkov, kjer tradicionalne konzervanse nadomeščamo s protimikrobnimi spojinami naravnega izvora. V okviru magistrske naloge smo preskusili učinkovitost 33, na trgu dostopnih protimikrobnih snovi naravnega izvora. V dermalnih kozmetičnih formulacijah smo uporabili njihove najmanjše in največje koncentracije, ki jih priporočajo proizvajalci. Začetno število mikroorganizmov v formulacijah smo preverili s preskusom, navedenim v Evropski farmakopeji, ki temelji na določanju skupnega števila aerobnih bakterij ter skupnega števila kvasovk in plesni. Za ovrednotenje potencialne mikrobne rasti smo preskus ponovili dva meseca po prvem odprtju pripravka. Predpisanih zahtev ni izpolnjevala le formulacija z 1,0 % Leucidal Liquid® PT (ferment Lactobacillus), kjer je prišlo do kontaminacije s plesnijo, medtem ko so preostale preskušane formulacije dokazale ustrezno mikrobiološko kakovost. Izvedli smo tudi izzivni preskus po predpisih standarda ISO 11930, kjer smo formulacije inokulirali s Pseudomonas aeruginosa in Aspergillus brasiliensis ter nato 28 dni spremljali upadanje števila dodanih mikroorganizmov. Pri izzivnem preskusu s P. aeruginosa so vse formulacije z izjemo tiste brez dodane protimikrobne snovi in 1,0 % Leucidal® Liquid PT ustrezale zahtevam kriterija. Pri preskusu z A. brasiliensis pa zahtev kriterija niso izpolnjevale formulacije z 0,2 % Geogard® 221 (dehidroocetna kislina, benzil alkohol), 1,5 % Verstatil® SL (voda, natrijeva sol levulinske kisline, kalijev sorbat) ter 2,0 % Verstatil® Synacid (voda, glicerol, natrijeve soli levulinske, salicilne in janežne kisline). Pri nekaterih formulacijah, ki so izpolnjevale zahteve kriterija, smo zaznali organoleptične spremembe in razrast plesni. Čeprav standard ISO 11930 za takšne okoliščine nima izrecnih navodil, smo mikrobiološko zaščito naslednjih dodanih protimikrobnih snovi smatrali kot nezadostno: 2,0 % in 4,0 % Arborcide® OC (voda, filtrat fermenta Leuconostoc), 2,0 % Leucidal® Liquid (bakterijski ferment korenine redkvice), 2,0 % Leucidal® Liquid Complete (voda, bakterijski ferment korenine redkvice, izvleček plodu kokosa z Lactobacillus), 0,25 % PlantservativeTM WSr (izvleček cvetov navadnega in japonskega kovačnika), 2,0 % Dermosoft® 1388 ECO (voda, glicerol, natrijeva sol levulinske in janežne kisline), 0,05 % Dermosoft® Anisate (natrijeva sol janežne kisline), 1,0 % in 3,0 % Phytocide Black Currant Powder (izvleček črnega ribeza).

• Language: Slovenian
• Keywords: Aspergillus brasiliensis, konzervans, naravne protimikrobne snovi, Pseudomonas aeruginosa, standard ISO 11930
• Work type: Master's thesis/paper
• Organization: FFA - Faculty of Pharmacy
• Year: 2021
• PID: 20.500.12556/RUL-133764
• Publication date in RUL: 15.12.2021

Secondary language

• Language: English
• Title: Antimicrobial test of selected compounds of natural origin in a dermal formulation using Pseudomonas aeruginosa and Aspergillus brasiliensis

Abstract

With natural cosmetics market blooming in recent years, the microbiological quality of cosmetic products has become a significant part of development and innovations in the cosmetic industry. Microbial spoilage leads to product degradation or in case of pathogens to potential health risks. To ensure consumer safety and protect cosmetic products against microbial contamination, we commonly use preservative. Results of research regarding the safety of certain chemical preservatives has driven the cosmetic industry to seek for their alternatives of natural origin. Hence, there is ample interest in development of cosmetic products in which traditional preservatives are replaced with antimicrobial substances of natural origin. In the master thesis we investigated the efficacy of 33 commercially available antimicrobials of natural origin. We used the minimum and maximum concentrations recommended by the manufacturer. Firstly, we analysed dermal formulations for total aerobic bacterial count and total combined yeast count according to European Pharmacopeia to determine the initial number of microorganisms. The test was repeated 2 months after first opening to establish potential microbial growth. The formulation with 1,0 % Leucidal® Liquid PT (Lactobacillus ferment) did not fulfil the criteria as it showed signs of fungal contamination, whereas all other tested formulations exhibited proper microbiological quality. Secondly, we performed a challenge test according to ISO 11930 standard, where we inoculated the formulations with Pseudomonas aeruginosa and Aspergillus brasiliensis and then observed the reduction of microorganisms during 28 days. In the challenge test with P. aeruginosa, the criterion was fulfilled by all formulations excluding one without a preservative and 1,0 % Leucidal® Liquid PT. As for A. brasiliensis; the formulations that did not fulfil criterion were 0,2 % Geogard® 221 (Dehydroacetic Acid, Benzyl Alcohol), 1,5 % Verstatil® SL (Aqua, Sodium Levulinate, Potassium Sorbate) and 2,0 % Verstatil® Synacid (Aqua, Glycerin, Sodium Levulinate, Sodium Salicylate, Sodium Anisate). We noticed organoleptic changes and signs of mold growth on the walls of containers in several formulations meeting criterion. Although ISO standard 11930 does not explicitly describe the procedure in this particular situation, we interpreted that preservation efficacy of the following antimicrobials is not sufficient: 2,0 % and 4,0 % Arborcide OC (Aqua, Leuconostoc Ferment Filtrate), 2,0 % Leucidal® Liquid (Leuconostoc/ Radish Root Ferment Filtrate), 2,0 % Leucidal® Liquid Complete (Aqua, Leuconostoc/ Radish Root Ferment Filtrate, Coconut Fruit Extract), 0,25 % Plantservative WSr (Lonicera Japonica Flower Extract, Lonicera Caprifolium Flower Extract), 2,0 % Dermosoft 1388 ECO (Aqua, Glycerin, Sodium Levulinate, Sodium Anisate), 0,05% Dermosoft Anisate ECO (Sodium Anisate), 1,0 % and 3,0 % Phytocide Black Currant Powder (Black Currant Fruit Extract).

• Keywords: Aspergillus brasiliensis, natural antimicrobials, preservative, Pseudomonas aeruginosa, standard ISO 11930