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PubMed1993

Development and evaluation of a novel sterilizer with rotary vibrators.

A novel steam-air sterilizer with rotary vibrators was developed with the aim of promoting heat transfer and the effective sterilization of foods. To evaluate the effects of the sterilizer, experiments to examine heat transfer and sterilization tests were carried out. In the experiments to examine heat transfer, heat penetration factors of sterilizer with vibration, j and fh values, were 1.70 and 1.50, respectively, while those of sterilizer without vibration were 1.83 and 2.32, respectively. In the sterilization with vibration, no surviving cells were detected after 3 min, whereas 7 min were required for sterilization without vibration. The rate of the amino carbonyl reaction was repressed by heat treatment with vibration.

Amines↗
PubMed1995

Assessment of the efficacy of a low temperature hydrogen peroxide gas plasma sterilization system.

The STERRAD 100 sterilization system (Johnson & Johnson Medical Ltd) uses low temperature hydrogen peroxide gas plasma for sterilization of heat labile equipment. The efficacy of the machine was tested by contaminating a standard set of instruments with different organisms and using a filtration method to assess recovery of organisms from the wash fluids of instruments post-sterilization. Experiments were performed under clean (the organism only) and dirty (organism mixed with egg protein) conditions. A parallel study conducted using a 3M STERIVAC ethylene oxide sterilizer could not be completed owing to closure of the ethylene oxide plant. For sterilization of instruments with long and narrow lumens, hydrogen peroxide adaptors are necessary. The STERRAD 100 sterilizer can achieve effective sterilization of heat labile instruments with a reduction of 6 log10 cfu/mL of organisms tested. This method has the advantages over ethylene oxide sterilization of safety, ease of maintenance and no requirement for aeration time.

Clostridium perfringens↗
PubMed1990

Efficiency of skin sterilization for a venipuncture with the use of commercially available alcohol or iodine pads.

Skin sterilization for a venipuncture is routinely done with commercially available alcohol or iodine pads. Selection of the antiseptics, alcohol or iodine, however, in most situations has been made on the basis of very little scientific data. With many patients with granulocytopenia who are undergoing venipunctures, the choice of antiseptic may be an important factor in preventing infections. We investigated two widely and commercially available disinfectant pads, alcohol and iodine, in the efficacy of skin sterilization. Seventy subjects (35 adults and 35 children) were randomly selected for this study. A designated area of the right and left forearm was sterilized either with alcohol or with an iodine pad in a predetermined uniform fashion. Specimens were obtained for cultures before and after sterilization. The bacterial cultures were performed with the use of blood agar plates and trypticase soy broth. For data analysis growth of any organisms on agar plates or trypticase soy broth after sterilization was interpreted as a sterilization failure. The iodine swab was significantly more efficient than the alcohol swab; the former yielded an 80% sterilization rate whereas the latter resulted in a rate of 61% (p less than 0.02). If, however, the growth only in agar plates was compared, the alcohol wipe yielded no growth in 83% and iodine in 84%, virtually identical success rates. Bacillus spp. predominated the residual organisms after either the alcohol or the iodine wipe. A variety of other organisms, however, including Staphylococcus and Corynebacterium spp., grew after alcohol but not after iodine sterilization.(ABSTRACT TRUNCATED AT 250 WORDS)

1-Propanol↗
PubMed2005

Steam sterilization and automatic dispensing of [18F]fludeoxyglucose (FDG) for injection.

UNLABELLED: For the purpose of implementing steam sterilization of 2-[18F]FDG (FDG) in the final container into routine production, we have validated and established a fully automated dispensing and sterilization system, thereby considerably reducing the radiation burden to the personnel. METHODS: The commercially available system combines aseptic dispensing of the product solution under a miniaturized laminar flow unit with subsequent steam sterilization, realized by heating of the product in the final containers by an autoclave included in the dispensing unit, thus incorporating current pharmaceutical manufacturing standards for the production of parental radiopharmaceuticals. The efficiency of the used sterilization cycle, the stability of FDG under the conditions of sterilization and the stability of the final product towards radiolysis was investigated with respect to various pH-formulations. RESULTS: The system was found to be fully valid for filling of vials in a laminar flow class A (US-class 100) environment and for sterilization of FDG in the final container. The pH for sterilizing FDG solutions must be slightly acidic to avoid decomposition. A pH of 5.5 appears to be optimal and gives FDG of very high radiochemical purity (approximately 99%). In addition, radiolysis of FDG in solutions of high activity concentration was significantly lower at pH 5.5 than at neutral pH. CONCLUSION: Terminal sterilization enables the production of FDG in full compliance with GMP-regulations even in Class C or D (US class 10,000 or 100,000) laboratories.

Fluorodeoxyglucose F18↗
PubMed2006

Microbiological safety and clinical efficacy of radiation sterilized amniotic membranes for treatment of second-degree burns.

Amniotic membranes collected from the placentae of screened donors were processed and sterilized by gamma irradiation at 25 kGy. The sterility assurance level (SAL) of gamma irradiated amniotic membranes and clinical efficacy in second-degree burn wound healing were evaluated. Processed air-dried amniotic tissue from 159 batches of processing was checked for the bioburden level before sterilization. About 39% of the tissues had bioburden in the range of 10(1)-10(2)/100 cm(2) and 54.8% in the range of 10(2)-10(3)/100 cm(2). Based on the bioburden of the processed tissue prior to sterilization and the D(10) value of 2.3 kGy for the radiation resistant reference strain Bacillus pumilus, the sterility assurance level of the amniotic membranes irradiated at 25 kGy is found to be 10(-7) to 10(-11). The burn wound healing rate was compared between the radiation sterilized amniotic membranes and glycerol preserved amniotic membranes. Fifty patients with partial-thickness burns (up to 70% TBSA) were selected for the study. The scalds constituted 82% (41 patients) whereas flame burns accounted for 18% (9 patients). Various aspects like ease of application, patient comfort, development of fluid under the membrane, bacterial culture of drained fluid, rate of epithelialization, development of hypertrophic scars, keloids, unstable scars and restriction of joint movements were recorded with the application of gamma irradiated and glycerol preserved membranes. Radiation sterilized amniotic membranes had advantage over the glycerolized membranes with respect to the ease of application. Five patients with glycerol preserved membranes and four with gamma irradiated membranes developed fluid. The bacteriology of fluid showed Pseudomonas aeruginosa in four cases, Staphylococcus aureus in two cases, Escherichia coli in two cases and Acinetobacter in one case. The application of radiation sterilized amniotic membranes on the burn wound favoured epithelialization. In all the patients, membranes dessicated and separated in 10-14 days time leaving behind an epithelialized surface.

Adult↗
PubMed2006

An in vitro analysis of microbial transmission during EUS-guided FNA and the utility of sterilization agents.

BACKGROUND: The risk of infection and potential microbial transmission with EUS-guided FNA (EUS-FNA) of cystic lesions remains unknown. OBJECTIVE: We developed an in vitro model to study the incidence of transmucosal microbial transmission during EUS-FNA of cystic lesions and to evaluate the in vitro efficacy of bacteriocidal agent washings of mucosa before FNA under experimental conditions. DESIGN: Conical tubes, 15 mL, filled with aerobic blood culture bottle media were prepared. Then sterile sections of bovine tripe were fastened over the top of the conical tubes in a sterile fashion (conical tube-tripe unit). FNA was performed with 22-gauge FNA needles. A series of 6 experiments were performed. Ten conical tube-tripe units underwent FNA once through the tripe into the blood culture media to ensure sterility. The surface of 10 conical tube-tripe units were inoculated with 50 microL of a 1.5 x 10(8) 1:1 mixture of Escherichia coli (E coli) and Enterococcus sp, and FNA was performed one time into the blood culture media to ensure contamination (controls). The surface of 40 conical tube-tripe units were inoculated with 50 microL of a 1.5 x 10(8) 1:1 mixture of E coli and Enterococcus sp Each of 4 sets of 10 conical tube-tripe units underwent experimental scenarios that consisted of washings with either 1 mL of 0.5% povidone iodine, chlorhexidine, absolute ethanol, or sterile water. FNA was performed once through the tripe into the blood culture media after washing the surface of the tripe. After each conical tube-tripe unit underwent FNA one time, 1 mL blood culture media was obtained and mixed on pour plate agar media and was incubated along with the conical tubes. Microbial evaluation of the conical tubes that contained the blood culture media and pour plates was performed after 48 hours of incubation. SETTING: Gastroenterology and Microbiology Departments of Scott White Memorial Hospital and Clinic in Temple, Texas. INTERVENTIONS: EUS-FNA of cystic lesions. MAIN OUTCOME MEASUREMENTS: Microbial contamination during EUS-FNA of an in vitro cystic environment. RESULTS: A control without E coli and Enterococcus sp was with 0% contamination. A control group with E coli and Enterococcus sp was with 100% contamination; sterile water washings, 100% contamination (P = 1.00); iodine washings, 20% contamination (P < .001); chlorhexidine washings, 80% contamination (P = .47); and absolute ethanol washings, 90% contamination (P = 1.00). Results were compared with our control group by statistical tests of proportions by using the Fisher exact test. CONCLUSIONS: EUS-FNA of sterile cystic lesions resulted in transmucosal microbial contamination. However, our model demonstrated that iodine sterilization of a contaminated mucosal surface produced a very highly statistically significant (P < .001) reduction in the transmission of infectious agents into a sterile environment. This in vitro model could translate into clinical practice by providing evidence that microbial transmission by FNA occurred. The utility of povidone iodine washings could alter procedure methods and patient care.

Animals↗
PubMed1996

The sterilization of endodontic hand files.

Several different methods of file sterilization were analyzed to determine the best method of providing complete file sterility, including the metal shaft and plastic handle. Six test groups of 15 files were studied using Bacillus stearothermophilus as the test organism. Groups were "sterilized" by glutaraldehyde immersion, steam autoclaving, and various techniques of salt sterilization. Only proper steam autoclaving reliably produced completely sterile instruments. Salt sterilization and glutaraldehyde solutions may not be adequate sterilization methods for endodontic hand files and should not be relied on to provide completely sterile instruments.

Colony Count, Microbial↗
PubMed1999

The effect of solvent extraction and sterilization procedure on the tissue response to Dacron velour.

The effects of solvent extraction and sterilization procedure on tissue response to Dacron velour were studied in a canine model, using histomorphometrical techniques. The solvents used for extraction of low molecular weight moieties were either ethanol or water: the sterilization techniques examined were ethylene oxide (ETO) treatment, steam sterilization, and radiofrequency glow discharge (RFGD) treatment. The effect of the sterilization procedure was most marked in the outermost regions (velour) of the implant; no sterilization effects were determined in the capsule or the knitted regions. Velour in the steam sterilized implants had the smallest blood vessel dimensions compared with those that were treated with ETO or RFGD. The effects of different extraction methodologies appeared to be more significant than sterilization effects and were detected further into the implant. That is, not only were extraction effects detected in the capsule and velour, they were also detected in the outer knitted region. Extraction with water resulted in histological responses considered more biologically desirable (thinner capsule, lower giant cell presence, and larger blood vessel diameters) than responses to extraction with ethanol. Neither extraction nor sterilization effects were detected in the inner layers of the knitted region, which were adjacent to the adhesive.

Animals↗
PubMed1997

[Peracetic acid: alternative to the sterilization of bronchofibroscopes].

The Steris system for cold sterilization with peracetic acid was evaluated by effecting a series of contaminations of a fiberoptic bronchoscope (FB) with specimens of Pseudomonas aeruginosa, Acinetobacter baumanii and Mycobacterium kansasi. The FB was contaminated 24 times, 8 times by each microorganism, using specimens containing more than 10(8) cfu/ml. After fixing the secretions on the FB and washing it with enzyme soap, the BF was sterilized. Specimens were taken for culturing after contamination of the FB, after washing, immediately after sterilization and 1 hour after sterilization. No microorganism growth of any of the samples was detected either immediately after sterilization or one hour later. Microbiological data confirmed contamination of the FB after aspiration and fixation of the inoculate. Chemical and biological tests with B. stearothermophilus spores as specified by the manufacturer were correct in all cases: 24 contaminations and 52 processes of prior training. The efficacy of washing with enzyme soap before sterilization stands out. In 14 of the 24 samples, culture was negative after washing and in 7 the concentration of microorganisms was less than 500 cfu/ml, which confirms the need for appropriate washing before any disinfection or sterilization process is begun. In conclusion, the Steris system based on peracetic acid is an alternative to other systems for cold sterilization or high level disinfection.

Acinetobacter↗
PubMed1983

Proper monitoring of sterilization procedures used in oral surgery.

The sterilization procedures used by oral surgeons in Norway have been surveyed. In 22 of the 25 oral surgical clinics controlled, instruments were sterilized by saturated steam at 121 degrees C or 134 degrees C; 3 used a dry heat oven sterilizer; dry heat and/or gas sterilization procedures supplemented steam sterilization in 17 clinics. When these sterilization procedures were monitored with biological indicators, 5 autoclaves (challenged with B. stearothermophilus spores), 2 dry heat sterilizers (B. subtilis spores), and all the Harvey Chemiclaves tested (B. subtilis spores) did not inactivate the bacterial spores. A biological monitoring system that fulfills the valid requirements for sterilization procedures given by the national health authorities and that is reliable, convenient, economical and self-contained should be used routinely in oral surgery clinics.

Evaluation Studies as Topic↗
PubMed1999

Effect of sterilization on the cutting efficiency of rotary nickel-titanium endodontic files.

OBJECTIVE: Nickel-titanium instruments that offer greater flexibility than instruments made of other metallic materials have been developed. This study evaluated the behavior in vitro of nickel-titanium rotary instruments under repeated sterilization cycles. STUDY DESIGN: To investigate changes in cutting ability and superficial alterations, 36 ProFile instruments, 18 with a taper of .04 and 18 with a taper of .06, were exposed to different sterilization cycles. Samples were divided into 3 groups of 12 files each. The 12 group A samples were exposed to 14 cycles of sterilization for 30 minutes; the 12 group B samples were exposed to 7 cycles of sterilization for 30 minutes; the 12 group C samples were not sterilized and served as a control group. Chemical compositions of the near surface layers of samples of each group were determined by means of Auger spectroscopy. RESULTS: The instruments that underwent the greatest number of sterilizations (group A) showed in-depth distributions of chemical composition that were different from those seen in the control group; this was the result of greater amounts of titanium oxide on the surfaces of the sterilized instruments. The files of group A showed a decrease in cutting efficiency in comparison with those of the control group. CONCLUSIONS: On the basis of this research on nickel-titanium files, we determined that repeated sterilizations under autoclave alter the superficial structure of such instruments.

Dental Instruments↗
PubMed1999

Influence of sterilization on injectable bone biomaterials.

Injectable biomaterials used in bone surgery include acrylic bone cements, calcium phosphate cements, and new composite-type biomaterials with a mineral content and an organic phase dispersed or dissolved in water. Cellulose derivatives, chitosan solutions, alginates, and other polymers are studied as useful modifiers and binding agents in calcium phosphate cements. We have developed proprietary polyester copolymers including lactic acid moieties and present here results concerning the effect of sterilization on the physico-chemical properties of derived bone biomaterials. Chitosan solutions show a dramatic decrease in viscosity after 25-kGy gamma sterilization. Aqueous copolylactic solutions also show, by capillary electrophoresis, that hydrolysis occurs to liberate monomers after 25-kGy gamma sterilization. Heat sterilization also degrades chitosan solutions, and ultrafiltration is difficult because of high viscosity. However, apatite-copolylactic solids can be steam sterilized without deterioration. Gelatin has been used as a natural polymer to bind apatite particles. Gel exclusion chromatography reveals crosslinking of the chains by irradiation. Standard acrylic cements contain monomers sterilized by ultrafiltration because they do not tolerate irradiation. We have used ultrafiltration to prepare aqueous copolylactic solutions without polymer hydrolysis. Implantation of calcium phosphate cement modified by copolylactic acid in a rabbit metaphyseal model defect shows progressive substitution of the biomaterial by new bone tissue. At 3 months, a mild inflammatory reaction still remains associated with the continuing resorption of the biomaterial. These results show that interesting biological properties can be obtained with products not sterilized by irradiation. Undoubtedly, many biopolymers are fragile and, like reactive monomers, need to be sterilized by special methods if they are to be used in injectable, liquid form.

Animals↗
PubMed1992

Sterile filtration of a parenteral emulsion.

The Syntex adjuvant formulation (SAF) containing [thr1]-muramyldipeptide in an oil-in-water emulsion has proven to be an effective adjuvant eliciting both cell-mediated and humoral immune response. As a parenteral emulsion, sterility of the final product was a concern, and various methods of achieving sterility were considered. For emulsions, most conventional sterilization methods are not viable, requiring the more cumbersome technique of sterilizing individual components and assembling/manufacturing under sterile conditions. Emulsion vehicles were manufactured with various models in the Microfluidizer M110 series. All equipment examined was capable of reducing the average dispersed oil droplet size to approximately 160 nm, with varying size ranges. Operating at an internal equipment pressure of greater than 16,000 psi, with at least five cycles through the interaction chamber, the resulting emulsion had a narrow droplet size range distribution, with the largest droplets being small enough to enable sterile filtration. Under specific-manufacturing conditions, the adjuvant emulsion becomes easily filtered through a 0.22-micron cartridge filter, thus yielding a sterile end product. This is the first published example of emulsion sterilization being achieved by terminal filtration.

Chemistry, Pharmaceutical↗
PubMed2000

Sterilization of reusable implant components: a pilot study.

STATEMENT OF PROBLEM: The placement and restoration of dental implants require the use of numerous reusable instruments and components. The adequate sterilization of reusable instruments and components is essential to prevent cross contamination between patients. Sterilization usually is accomplished with single-use sterilization envelopes. A reusable sterilization vehicle would reduce costs as well as the waste generated in patient care. PURPOSE: This study was designed to determine the efficacy of a 10-cc Pyrex test tube as a sterilization vehicle for reusable dental implant instruments and components. MATERIAL AND METHODS: In this study, a reusable dental implant component was placed in a Pyrex test tube, along with a biologic test strip. A control biologic test strip was kept for each test tube. The test tube was closed with a cotton roll folded in half and placed in the opening. Twenty test tubes were prepared. five sets of 4 test tubes were placed in an autoclave in different locations with varying orientations. The autoclave completed a standard sterilization cycle. RESULTS: The biological monitoring service indicated that the biologic test strips in 100% of the test tubes were sterile, whereas the control strips were 100% nonsterile. CONCLUSION: A Pyrex test tube sealed with a cotton roll can serve as a sterilization vehicle for reusable dental implant instruments and components.

Bacillus subtilis↗
PubMed2003

Increase in early polyethylene wear after sterilization with ethylene oxide: radiostereometric analyses of 201 total hips.

We evaluated polyethylene wear by measuring femoral head penetration in 201 THA (median age 62 (31-81) years, 117 women) extracted from 5 randomized studies aimed to assess various fixation principles. There were 30 cemented all-polyethylene Lubinus cups sterilized by gamma irradiation in a reduced oxygen environment, 65 porous-coated Trilogy cups with liners gamma-sterilized in inert gas. Moreover, 37 cemented cups were sterilized with ethylene oxide (Reflection all-poly) and 69 porous-coated cups had liners sterilized in ethylene oxide (Reflection). 28 mm femoral heads were used in all cups. The patients were followed with repeated radiostereometric measurements (RSA) up to 2 years. The activity level of the patients was evaluated by a questionnaire. After 2 years, cups with polyethylene sterilized in EtO had almost twice the proximal and 3D penetration rates, as compared with gamma-sterilized polyethylene. The penetration did not differ between the gamma-irradiated designs. Using stepwise linear regression analysis, we found that the type of sterilization, age and weight were the most important predictors and that they determined the direction of the proximal penetration rate. Activity score, male gender and proximal migration of the cup had little effect. The accelerated wear observed with the EtO-sterilized polyethylene causes concerns about long-term problems and especially in younger patients.

Adult↗
PubMed1999

Development and evaluation of a laboratory-scale apparatus to simulate the scale-up of a sterile semisolid and effects of manufacturing parameters on product viscosity.

The purpose of this study was to develop a benchtop apparatus to simulate the scale-up of the moist-heat sterilization process of sodium carboxymethylcellulose (CMC) gel and identify critical process parameters that affect the sterilized gel viscosity. A 600-ml benchtop Parr reactor was modified and used to achieve good correlation with a previously established heating profile using different equipment at the manufacturing site. The Parr reactor is constructed with 316 stainless steel, pressure rated to 2000 psig, and temperature rated to 350 degrees C. After several trials, a low-wattage heater (300 W) was determined to be suitable for this sterilization process (122 degrees C for 20 min). An anchor stirrer was installed for more efficient mixing while the gel was being sterilized. Evacuation and nitrogen flushing of the vessel could easily be performed through the gas inlet valves. The temperature controller (model 4843) has a microprocessor-based control module that provides a temperature profile control with adjustable tuning parameters. This apparatus was used to mimic the full-scale sterilization process by simulating the production sterilization temperature profile. Using this device, we found that the critical process parameters that affected final product viscosity were heating time, the starting pressure, residual oxygen concentration in the vessel, and the inherent viscosity of the CMC raw material. This study indicated that it is possible to use the Parr reactor to simulate the scale-up sterilization process of a semisolid product. A product with a consistent viscosity range could be manufactured by controlling critical process parameters during sterilization.

Carboxymethylcellulose Sodium↗
PubMed2004

Disinfection and sterilization in health care facilities: what clinicians need to know.

All invasive procedures involve contact between a medical device or surgical instrument and a patient's sterile tissue or mucous membranes. A major risk of all such procedures is the introduction of pathogenic microbes that could lead to infection. Failure to properly disinfect or sterilize reusable medical equipment carries a risk associated with breach of the host barriers. The level of disinfection or sterilization is dependent on the intended use of the object: critical items (such as surgical instruments, which contact sterile tissue), semicritical items (such as endoscopes, which contact mucous membranes), and noncritical items (such as stethoscopes, which contact only intact skin) require sterilization, high-level disinfection, and low-level disinfection, respectively. Cleaning must always precede high-level disinfection and sterilization. Users must consider the advantages and disadvantages of specific methods when choosing a disinfection or sterilization process. Adherence to these recommendations should improve disinfection and sterilization practices in health care facilities, thereby reducing infections associated with contaminated patient-care items.

Cross Infection↗
PubMed1996

National survey of quality assurance activities for pharmacy-prepared sterile products in hospitals and home infusion facilities--1995.

The results of a survey of hospital pharmacy and home infusion facility activities for quality assurance in the preparation of sterile drug products are reported, and the hospital results are compared with those of a 1991 ASHP survey. A questionnaire was mailed in May and June 1995 to 778 hospital pharmacy directors and 203 home infusion pharmacy directors. Usable questionnaires were returned by 547 hospitals and 111 home infusion facilities, for an overall response rate of 67%. The percentages of hospitals with pharmacists involved in extemporaneous (70%) and batch (28%) preparation of sterile drug products have decreased since 1991, while the percentage with technicians who are not limited as to the types of sterile products they may prepare has increased. Some 16% of all sterile products compounded in hospitals were prepared by nonpharmacy personnel. Few respondents contracted with outside sources for compounding of sterile products. A need for educational programs on aseptic technique was identified by 83% of hospitals, and 84% of home infusion facilities indicated a need for education on environmental monitoring. Three fourths of respondents used the ASHP Technical Assistance Bulletin on Quality Assurance for Pharmacy-Prepared Sterile Products in developing their policies and procedures. Significant improvements in orientation and training techniques have occurred since 1991. Use of a laminar-airflow hood in a limited-access room has increased. The aspects of sterile product compounding most often modified since 1991 were, for hospitals, personnel training and evaluation (74%), facilities and equipment (48%), and garb policies (36%); for home infusion facilities, personnel training and evaluation (76%), facilities and equipment and garb policies (both 69%), and end-product testing and evaluation (66%). There have been advances in quality assurance procedures related to pharmacy-prepared sterile products, but opportunities for improvement remain.

Drug Compounding↗