Evaluation of preservative effectiveness in pharmaceutical products: the use of a wild strain of Pseudomonas cepacia

Polyphenols: Natural Preservatives with Promising Applications in Food, Cosmetics and Pharma Industries; Problems and Toxicity Associated with Synthetic Preservatives; Impact of Misleading Advertisements; Recent Trends in Preservation and Legislation

The global market of food, cosmetics, and pharmaceutical products requires continuous tracking of harmful ingredients and microbial contamination for the sake of the safety of both products and consumers as these products greatly dominate the consumer's health, directly or indirectly. The existence, survival, and growth of microorganisms in the product may lead to physicochemical degradation or spoilage and may infect the consumer at another end. It has become a challenge for industries to produce a product that is safe, self-stable, and has high nutritional value, as many factors such as physical, chemical, enzymatic, or microbial activities are responsible for causing spoilage to the product within the due course of time. Thus, preservatives are added to retain the virtue of the product to ensure its safety for the consumer. Nowadays, the use of synthetic/artificial preservatives has become common and has not been widely accepted by consumers as they are aware of the fact that exposure to preservatives can lead to adverse effects on health, which is a major area of concern for researchers. Naturally occurring phenolic compounds appear to be extensively used as bio-preservatives to prolong the shelf life of the finished product. Based on the convincing shreds of evidence reported in the literature, it is suggested that phenolic compounds and their derivatives have massive potential to be investigated for the development of new moieties and are proven to be promising drug molecules. The objective of this article is to provide an overview of the significant role of phenolic compounds and their derivatives in the preservation of perishable products from microbial attack due to their exclusive antioxidant and free radical scavenging properties and the problems associated with the use of synthetic preservatives in pharmaceutical products. This article also analyzes the recent trends in preservation along with technical norms that regulate the food, cosmetic, and pharmaceutical products in the developing countries.

Thermodynamic investigation of the interaction between cyclodextrins and preservatives - Application and verification in a mathematical model to determine the needed preservative surplus in aqueous cyclodextrin formulations

Preservatives are inactivated when added to conserve aqueous cyclodextrin (CD) formulations due to complex formation between CDs and the preservative. To maintain the desired conservation effect the preservative needs to be added in apparent surplus to account for this inactivation. The purpose of the present work was to establish a mathematical model, which defines this surplus based upon knowledge of stability constants and the minimal concentration of preservation to inhibit bacterial growth. The stability constants of benzoic acid, methyl- and propyl-paraben with different frequently used βCDs were determined by isothermal titration calorimetry. Based upon this knowledge mathematical models were constructed to account for the equilibrium systems and to calculate the required concentration of the preservations, which was evaluated experimentally based upon the USP/Ph. Eur./JP monograph. The mathematical calculations were able to predict the needed concentration of preservation in the presence of CDs; it clearly demonstrated the usefulness of including all underlying chemical equilibria in a mathematical model, such that the formulation design can be based on quantitative arguments.

Burkholderia cepaciaInfections Associated With Intrinsically Contaminated Ultrasound Gel: The Role of Microbial Degradation of Parabens

Objective:

To describe an outbreak of serious nosocomialBurkholderia cepaciainfections occurring after transrectal prostate biopsy associated with ultrasound gel intrinsically contaminated with paraben-degrading microorganisms.

Methods:

A retrospective chart review prompted by a blood culture isolate ofB, cepacia.Identification of microorganisms in ultrasound gel in two Canadian centers and characterization by pulsed-field gel electrophoresis and assays for paraben degradation.

Setting:

Two Canadian university-affiliated, tertiary-care centers in Newfoundland and Alberta.

Results:

Six seriousB. cepaciainfections were identified at the two centers. Isolates ofB. cepaciarecovered from the blood of patients from both centers and the ultrasound gel used during the procedures were identical, confirming intrinsic contamination. Strains ofEnterobacter cloacaeisolated from ultrasound gel at the two centers were also identical. The ability to degrade parabens was proven for bothB. cepaciaandE. cloacaestrains recovered from the ultrasound gel.

Conclusions:

Ultrasound gel is a potential source of infection. Contamination occurs at the time of manufacture, with organisms that degrade parabens, which are commonly used as stabilizing agents. There are far-reaching implications for the infection control community.

Comparison of antimicrobial activity of essential oils, plant extracts and methylparaben in cosmetic emulsions: 2 months study

The aim of the study was to compare the preservative effectiveness of plant extracts (Matricaria chamomilla, Aloe vera, Calendula officinalis) and essential oils (Lavandulla officinalis, Melaleuca alternifolia, Cinnamomum zeylanicum) with methylparaben in cosmetic emulsions against skin microflora during 2 months of application by volunteers. Cosmetic emulsions with extracts (2.5 %), essential oils (2.5 %), methylparaben (0.4 %) or placebo were tested by 40 volunteers during 2 months of treatment. In order to determine microbial purity of the emulsions, the samples were taken after 0, 2, 4, 6 and 8 weeks of application. Throughout the trial period it was revealed that only cinnamon oil completely inhibited the growth of bacteria, yeast and mould, as compared to all other essential oils, plant extracts and methylparaben in the tested emulsions. This result shows that cinnamon oil could successfully replace the use of methylparaben in cosmetics, at the same time ensuring microbiological purity of a cosmetic product under its in-use and storage conditions.

Investigation of current infection-control practices for ultrasound coupling gel: a survey, microbiological analysis, and examination of practice patterns

BACKGROUND AND OBJECTIVES

Ultrasound coupling gel may serve as a vector for the spread of bacteria and has been the causative agent for significant health care-associated infections. The purpose of this study was to document existing infection-control procedures and level of contamination present within nonsterile ultrasound gel from several clinical departments at a single institution. A second purpose was to examine the effectiveness of clinician education and manufacturer-based ultrasound additives on ultrasound gel contamination and in vitro bacterial proliferation, respectively.

METHODS

Compliance with Health Canada recommended infection-control policies were determined by survey. Contamination of in-use ultrasound gel bottles was determined by inspecting cultures after 72 hours of incubation. After infection-control education, a 28-day interval assessment was used to examine contamination rates in newly provided ultrasound gel. The ability of ultrasound gel containing parabens to prevent bacterial growth was examined in cultures grown with and without ultrasound gel.

RESULTS

Practitioners were not compliant with Health Canada recommendations, but the baseline ultrasound gel contamination rate within these departments was only 2.5%. Education in infection control did not improve the contamination rate over 28 days. Contamination was discovered in ultrasound gel supplied directly from the manufacturer. Ultrasound gel suppressed but did not prevent bacterial growth in a species- and time-specific manner.

CONCLUSIONS

The source of contamination for in-use ultrasound gel may be of manufacturer or human origin. Because additives to the ultrasound gel are not bactericidal, sterile ultrasound gel should be used for invasive and high-risk cases, and improving infection-control policies is warranted.

Rubus rosaefolius extract as a natural preservative candidate in topical formulations

Even though the synthetic preservatives may offer a high antimicrobial efficacy, they are commonly related to adverse reactions and regarded as having potentially harmful effects caused by chronic consumption. The development of natural preservatives provides a way of reducing the amount of synthetic preservatives normally used in pharmaceutical and cosmetic preparations. In addition, these agents have less toxic effects and represent a possible natural and safer alternative of the preservatives. The purpose of this research was to evaluate the Rubus rosaefolius Smith extract efficiency as a natural preservative in base formulations. Of the extract, 0.2% (w/w) was assayed for its effectiveness of antimicrobial protection in two different base formulations (emulsion and gel). The microbial challenge test was performed following the standard procedures proposed by The United States Pharmacopoeia 33nd, European Pharmacopoeia 6th, Japanese Pharmacopoeia 15th, and the Cosmetics, Toiletries, and Fragrance Association using standardized microorganisms. The results demonstrated that R. rosaefolius extract at the studied concentration reduced the bacterial inocula, satisfying the criterion in all formulations, even though it was not able to present an effective preservative behavior against fungi. Thus, the investigation of new natural substances with preservative properties that could be applied in pharmaceutical and cosmetic products is relevant due to the possibility of substituting or decreasing the concentration of synthetic preservatives, providing a way for the development of safer formulas for the use of consumers.

Efficiency of Calamintha officinalis essential oil as preservative in two topical product types

AIMS

To verify the efficiency of Calamintha officinalis essential oil as natural preservative in two current formulations.

METHODS AND RESULTS

The 1.0 and 2.0% (v/v) C. officinalis essential oil was assayed for its preservative activity in two product types (cream and shampoo). The microbial challenge test was performed following the standards proposed by the European Pharmacopoeia Commission (E.P.) concerning topical preparations using standard micro-organisms and in addition wild strains, either in single or mixed cultures were used. The results clearly demonstrated that the C. officinalis essential oil at 2.0% concentration reduced the microbial inoculum satisfying the criterion A of the E.P. in the cream formulation and the criterion B in the shampoo formulation. Standard and wild strains showed a behaviour similar, both in cream and in shampoo formulation, with no significant difference (gerarchic variance, P > 0.05).

CONCLUSION

C. officinalis essential oil confirmed its preservative properties but at higher concentration than that shown in previous studies on cetomacrogol cream.

SIGNIFICANCE AND IMPACT OF THE STUDY

The nature of the formulation in which an essential oil is incorporated as preservative could have considerable effect on its efficacy.