Safety assessment and adverse drug reaction reporting of tea tree oil (Melaleuca aetheroleum).

Tea tree (Melaleuca alternifolia) essential oil is widely used as an antiseptic. It mainly consists of monoterpenes with terpinen-4-ol as the major constituent. The aim of this study was to review literature on safety data about tea tree oil and to assess its safety by investigating 159 cases of adverse reactions possibly caused by the oil, reported to the World Health Organization (WHO) from December 1987 until September 2021. To extract these data, VigiBase, the WHO global database of individual case safety reports maintained by the Uppsala Monitoring Centre (UMC), was used. All cases were categorized and analysed and 16 serious cases further assessed. It was concluded that tea tree oil should never be administered orally, as it can lead to central nervous system depression and pneumonitis. Applied topically, skin disorders may occur, especially when the oil had been exposed to light or air. This yields monoterpene oxidation products, being potent skin irritants. Tea tree oil stored under appropriate conditions and not exceeding the expiration date should be considered safe to use by non-vulnerable people for non-serious inflammatory skin conditions, although the occurrence of adverse reactions such as contact allergies is difficult to predict.

A Retrospective Surveillance of the Antibiotics Prophylactic Use of Surgical Procedures in Private Hospitals in Indonesia.

Background: According to international guidelines, prophylactic antibiotics in elective surgery should be given as a single dose 30 to 60 minutes before the operation is conducted. Postoperative administration of antibiotics should be discontinued 24 hours after surgery to minimize bacterial resistance and to keep control over hospitalization costs. There is a lack of data on the actual antibiotic use around surgical procedures in Indonesia. Objective: This retrospective surveillance study aimed to obtain defined daily doses (DDD) and DDDs per 100 bed days (DDD-100BD) for prophylactically used antibiotics in two private hospitals in Surabaya, East Java. These hospitals are considered to be representative for the current situation in Indonesia. Method: Data from a total of 693 patients over a nearly 1-year period (2016) were collected and evaluated. Results: The overall DDD per patient was 1.5 for hospital A and 1.7 for hospital B. The overall DDD-100BD was 30 for hospital B. Of the 24 antibiotics given prophylactically, ceftriaxone was the most commonly used in both hospitals. Conclusion: There was a clear discrepancy between daily practice in both hospitals and the recommendations in the guidelines. This study shows that better adherence to antibiotic stewardship is needed in Indonesia. Substantial improvements need to be made toward guided precision therapy regarding quantity (dose and frequency), route of administration (prolonged intravenous), and choice of the type of antibiotic.

Personalized Medicine in Pediatrics: The Clinical Potential of Orodispersible Films.

Children frequently receive medicines that are designed for adults. The dose of commercially available products is adapted, mostly based on the child's bodyweight, thereby neglecting differences in pharmacokinetic and pharmacodynamics parameters. If commercial products are unsuitable for administration to children or are unavailable, extemporaneous pharmacy preparations are a good alternative. For this particular population, orodispersible films (ODFs) can be a highly attractive dosage form for the oral administration of drugs. ODFs are relatively easy to prepare in a hospital setting, create dose flexibility, and may suit an individual approach, especially for patients having difficulties in swallowing tablets or being fluid restricted. In this article, various aspects related to pharmacy preparations, clinical application, and preparation of ODFs for pediatric patients are highlighted and discussed.

Development and Implementation of an Ultraviolet-Dye-Based Qualification Procedure for Hand Washing and Disinfection to Improve Quality Assurance of Pharmacy Preparations and Compounding, Especially in Cleanrooms: A Pilot Study.

Even though, nowadays, most medicines are manufactured industrially, patients may have medical needs that can only be met by a tailor-made approach. This requires the availability of pharmacy preparations made under Good Manufacturing Practice (GMP) conditions. An efficient hand hygiene practice is essential herewith, especially if sterile products that are prepared in a cleanroom are concerned. The effectiveness of hand washing and hand disinfection procedures greatly relies on adequate training. We carried out an observational cross-sectional pilot study aimed at optimizing hand hygiene training with objective and measurable quality assessments using an ultraviolet (UV) dye. Practical acceptance criteria for qualifying personnel through this method were set and evaluated. In total, 25 GMP-qualified cleanroom operators washed and disinfected their hands with UV dye hand wash lotion and UV dye hand alcohol, respectively. To obtain a proof-of-concept, the results were judged based on adherence to the WHO six-step protocol and associated acceptance criteria. Commonly missed areas were brought to light, and the influence of procedure duration was investigated. UV-dye-based assessments appeared to be more valuable in hand disinfection than in hand washing. In both procedures, the back of the hands and the thumbs were frequently missed. This underpins the need for enhanced and repeated education on hand washing and disinfection. Additionally, a dry skin gave rise to extra cleaning challenges. From this pharmacy practice pilot study with a focus on pharmaceutical product care, it may be concluded that the application of UV-dye-based assessments offers valuable insights for pharmacists to optimize hand hygiene, thereby increasing the safety of tailor-made medicines and on-site preparations.

The Therapeutic Potential of Essential Oils in Managing Inflammatory Skin Conditions: A Scoping Review.

Conventional therapy is commonly used for the treatment of inflammatory skin conditions, but undesirable effects, such as erythema, dryness, skin thinning, and resistance to treatment, may cause poor patient compliance. Therefore, patients may seek complementary treatment with herbal plant products including essential oils (EOs). This scoping review aims to generate a broad overview of the EOs used to treat inflammatory skin conditions, namely, acne vulgaris, dermatitis and eczema, psoriasis, and rosacea, in a clinical setting. The quality, efficacy, and safety of various EOs, as well as the way in which they are prepared, are reviewed, and the potential, as well as the limitations, of EOs for the treatment of inflammatory skin conditions are discussed. Twenty-nine eligible studies (case studies, uncontrolled clinical studies, and randomized clinical studies) on the applications of EOs for inflammatory skin conditions were retrieved from scientific electronic databases (PubMed, Embase, Scopus, and the Cochrane Library). As an initial result, tea tree (Melaleuca alternifolia) oil emerged as the most studied EO. The clinical studies with tea tree oil gel for acne treatment showed an efficacy with fewer adverse reactions compared to conventional treatments. The uncontrolled studies indicated the potential efficacy of ajwain (Trachyspermum ammi) oil, eucalyptus (Eucalyptus globulus) oil, and cedarwood (Cedrus libani) oil in the treatment of acne, but further research is required to reach conclusive evidence. The placebo-controlled studies revealed the positive effects of kanuka (Kunzea ericoides) oil and frankincense (Boswellia spp.) oil in the treatment of psoriasis and eczema. The quality verification of the EO products was inconsistent, with some studies lacking analyses and transparency. The quality limitations of some studies included a small sample size, a short duration, and the absence of a control group. This present review underscores the need for extended, well-designed clinical studies to further assess the efficacy and safety of EOs for treating inflammatory skin conditions with products of assured quality and to further elucidate the mechanisms of action involved.

Analysis of Safety Concerns on Herbal Products with Assumed Phytoestrogenic Activity.

Phytoestrogens (PEs) are plant-based compounds that can interact with estrogen receptors and are mainly used to treat menopausal complaints. However, the safety of products with assumed phytoestrogenic activity is not fully understood. This study aimed to identify plant species with assumed phytoestrogenic activity, review existing literature on their use and safety, and critically evaluate adverse reaction (AR) reports of single-herb, multi-herb, and mixed-multiple products, as submitted to the Netherlands Pharmacovigilance Centre Lareb and to VigiBase of the World Health Organization (WHO). In the Lareb database, the most commonly reported plant species to cause ARs (total of 67 reports) were Actaea racemosa L. (black cohosh) (47.8%), Humulus lupulus L. (hops) (32.8%), and Glycine max (L.) Merr. (soybean) (22.4%). In the VigiBase database (total of 21,944 reports), the top three consisted of Glycine max (L.) Merr. (71.4%), Actaea racemosa L. (11.6%), and Vitex agnus-castus L. (chaste tree) (6.4%). In the scoping review (total of 73 articles), Actaea racemosa L. (30.1%), Glycine max (L.) Merr. (28.8%), and Trifolium pratense L. (13.7%) were the most frequently mentioned plant species. ARs were most frequently reported in the system organ classes "gastrointestinal disorders", "skin and subcutaneous tissue disorders", "reproductive system and breast disorders", and "general disorders and administration site conditions". Furthermore, from the scoping review, it appeared that the use of products with assumed phytoestrogenic activity was associated with postmenopausal bleeding. It was concluded that, while the potential benefits of products with assumed phytoestrogenic activity have been extensively pursued, the potential occurrence of ARs after using these products is less well understood. This study highlights the need for further investigation and careful monitoring of these products to better understand their effects and ensure the safety and well-being of individuals using them.

Potential, Limitations and Risks of Cannabis-Derived Products in Cancer Treatment.

The application of cannabis products in oncology receives interest, especially from patients. Despite the plethora of research data available, the added value in curative or palliative cancer care and the possible risks involved are insufficiently proven and therefore a matter of debate. We aim to give a recommendation on the position of cannabis products in clinical oncology by assessing recent literature. Various types of cannabis products, characteristics, quality and pharmacology are discussed. Standardisation is essential for reliable and reproducible quality. The oromucosal/sublingual route of administration is preferred over inhalation and drinking tea. Cannabinoids may inhibit efflux transporters and drug-metabolising enzymes, possibly inducing pharmacokinetic interactions with anticancer drugs being substrates for these proteins. This may enhance the cytostatic effect and/or drug-related adverse effects. Reversely, it may enable dose reduction. Similar interactions are likely with drugs used for symptom management treating pain, nausea, vomiting and anorexia. Cannabis products are usually well tolerated and may improve the quality of life of patients with cancer (although not unambiguously proven). The combination with immunotherapy seems undesirable because of the immunosuppressive action of cannabinoids. Further clinical research is warranted to scientifically support (refraining from) using cannabis products in patients with cancer.

A non-invasive, low-cost study design to determine the release profile of colon drug delivery systems: a feasibility study.

PURPOSE: Conventional bioavailability testing of dosage forms based on plasma concentration-time graphs of two products in a two-period, crossover-design, is not applicable to topical treatment of intestinal segments. We introduce an isotope dual-label approach ((13)C- and (15)N(2)-urea) for colon drug delivery systems that can be performed in a one-day, non-invasive study-design. METHODS: Four healthy volunteers took an uncoated or a ColoPulse-capsule containing (13)C-urea and an uncoated capsule containing (15)N(2)-urea. In case of colon-release (13)C-urea is fermented and (13)C detected as breath (13)CO(2). Absorbed (13)C-urea and (15)N-urea are detected in urine. RESULTS: C and (15)N in urine released from uncoated capsules showed a ratio of 1.01 ± 0.06. The (13)C/(15)N-recovery ratio after intake of a ColoPulse-capsule was constant and lower >12 h post-dose (median 0.22, range 0.13-0.48). The (13)C/(15)N-ratio in a single urine sample at t ≥ 12 h predicted the 24 h non-fermented fraction (13)C of <26 %. Breath (13)CO(2) indicated delayed (>3 h) release and a fermented fraction (13)C >54 %. CONCLUSIONS: Breath and urine (13)C and (15)N data describe the release-profile and local bioavailability of a colon delivery device. This allows non-invasive bioavailability studies for evaluation of colon-specific drug delivery systems without radioactive exposure and with increased power and strongly reduced costs.

Film coated tablets (ColoPulse technology) for targeted delivery in the lower intestinal tract: influence of the core composition on release characteristics.

The design of a film coating technology which allows a tablet to deliver the drug in the ileocolonic segment would offer new treatment possibilities. The objective is to develop a platform technology that is suitable for a broad range of drug compounds. We developed a coated tablet with a delayed, pulsatile release profile based on a pH-sensitive coating technology (ColoPulse). The production process was validated, and the effect of core composition on the in vitro release and water uptake investigated. The release profile of the standard tablet core composition, based on the use of cellulose as a filler, was independent of the coat thickness in a range of 9.0-13.2 mg/cm(2). The release profile of a coated tablet was strongly influenced when cellulose was partly replaced by the model substance glucose (loss of sigmoidal release), citric acid (stabilization), sodium bicarbonate (destabilization) or sodium benzoate (destabilization). The film coating takes up water when below the pH-threshold. However, this did not cause early disintegration of the coating. The ColoPulse technology is successfully applied on tablets. The in vitro release characteristics of the coated tablets are influenced by the composition of the core.

The Development and Implementation of Airflow Visualization Studies ("Smoke" Studies) as a Training Tool in Aseptic Hospital Compounding Facilities.

In the compounding facilities of hospital pharmacies, extemporaneous preparations for parenteral administration are produced using aseptic handling. The designated environment for this practice is a clean area, such as a laminar airflow (LAF) cabinet placed in a classified cleanroom complying with good manufacturing practices (GMP) and International Organization for Standardization (ISO) 14644-1 guidelines. The European GMP Annex 1 (Revision 2020) and United States Pharmacopeia (USP) <797> monograph state that airflow visualization studies ("smoke" studies) should be performed to substantiate the cleanroom and LAF cabinet performance and their qualification status. Even though smoke studies are required by these guidelines, current literature does not describe detailed practical protocols and acceptance criteria. The objective of this study was to develop and implement a practical smoke study protocol to ensure compliance with aseptic handling guidelines in hospital pharmacies. First, a literature search was performed to collect information about smoke study protocols and acceptance criteria. Subsequently, a smoke study protocol was developed for a downflow and crossflow LAF cabinet as well as for grade C/B cleanroom areas. As a proof of concept, the smoke study protocol for the downflow LAF cabinet was executed in the at-rest and in-operation states. Video recordings of the smoke studies were analyzed to assess the performance of the cabinet. Finally, the video recordings obtained from the smoke studies were used in a training program for hospital pharmacy operators, which showed that smoke studies might aid in operators' aseptic handling awareness. To the best of our knowledge, the present study provides for the first time a practical approach for the development of smoke study protocols in a hospital pharmacy setting and shows potential for training operators, process optimization, and continuous quality improvement.

Analysis of Reports on Adverse Drug Reactions Related to Herbal Medicinal Products and Herbal Supplements in the Netherlands Received by the National Pharmacovigilance Centre Lareb.

INTRODUCTION: The inclusion of herbal medicinal products and herbal supplements in pharmacovigilance systems is important because a systematic approach of collecting and analyzing adverse drug reactions related to these products will help practitioners, patients, and regulators to gain more knowledge and prevent harm. OBJECTIVE: We aimed to categorize the adverse drug reaction reports on herbal medicinal products and herbal supplements submitted to the Pharmacovigilance Centre Lareb between 1991 and February 2021 on the basis of their regulatory status, herbs included, and adverse drug reactions involved. METHODS: We categorized products on the basis of their registration status and herbal ingredients. The products were then categorized according to the Herbal Anatomical Therapeutic Chemical Classification System. We used descriptive statistics in Microsoft Excel 2019. Pivot tables were used for the analysis and presentation of the data. RESULTS: Until February 2021, a total of 789 reports of herbal medicinal products and herbal supplements were received by Lareb. In these reports, a total of 823 herbal products were labeled as suspect. These products caused a total of 1727 adverse drug reactions. Of the 823 products, 229 were registered as a medicine, and 594 were on the market as a herbal supplement. Of the 823 herbal products, 522 reports concerned single-herb products, 256 reports concerned combination products, 27 reports concerned vitamin products containing herbal ingredients, and 18 reports concerned product issues. Approximately 15% of reports concerned serious adverse drug reactions, and adulterated products harbored a high risk of causing serious adverse drug reactions. CONCLUSIONS: Analysis of the herbal medicinal products and herbal supplements in the Dutch pharmacovigilance database revealed a variety of suspected herbal ingredients. The reports provide insight into the variety of herbal products used in the Netherlands and the adverse reactions associated with their use. Pharmacovigilance of herbal products is essential to ensure their safe use.

Performance of Tablet Splitters, Crushers, and Grinders in Relation to Personalised Medication with Tablets.

Swallowing problems and the required dose adaptations needed to obtain optimal pharmacotherapy may be a hurdle in the use of tablets in daily clinical practice. Tablet splitting, crushing, or grinding is often applied to personalise medication, especially for the elderly and children. In this study, the performance of different types of (commercially available) devices was studied. Included were splitters, screwcap crushers, manual grinders, and electric grinders. Unscored tablets without active ingredient were prepared, with a diameter of 9 and 13 mm and a hardness of 100-220 N. Tablets were split into two parts and the difference in weight was measured. The time needed to pulverise the tablets (crush time) was recorded. The residue remaining in the device (loss) was measured. The powder was sieved to obtain a particle fraction >600 µm and <600 µm. The median particle size and particle size distribution of the later fraction were determined using laser diffraction analysis. Splitting tablets into two equal parts appeared to be difficult with the devices tested. Most screwcap grinders yielded a coarse powder containing larger chunks. Manual and especially electric grinders produced a finer powder, making it suitable for administration via an enteral feeding tube as well as for use in individualised preparations such as capsules. In conclusion, for domestic and incidental use, a screwcap crusher may provide sufficient size reduction, while for the more demanding regular use in hospitals and nursing residences, a manual or electric grinder is preferred.

Applications of stable isotopes in clinical pharmacology.

This review aims to present an overview of the application of stable isotope technology in clinical pharmacology. Three main categories of stable isotope technology can be distinguished in clinical pharmacology. Firstly, it is applied in the assessment of drug pharmacology to determine the pharmacokinetic profile or mode of action of a drug substance. Secondly, stable isotopes may be used for the assessment of drug products or drug delivery systems by determination of parameters such as the bioavailability or the release profile. Thirdly, patients may be assessed in relation to patient-specific drug treatment; this concept is often called personalized medicine. In this article, the application of stable isotope technology in the aforementioned three areas is reviewed, with emphasis on developments over the past 25 years. The applications are illustrated with examples from clinical studies in humans.

Legislation and current developments in adverse drug reaction reporting in Mongolia: how far are we?

Monitoring adverse drug reactions is a vital issue to ensure drug safety and to protect the general public from medication-related harmful effects. In order to properly monitor drug safety, a regulatory system needs to be in place as well as an infrastructure that allows for analyzing national and international safety data. In Mongolia, adverse drug reaction (ADR) reporting activities have been implemented in the past decade. During this period, the basic structure and legal basis of an adverse drug reaction monitoring system was established. Because of the fragmented but growing healthcare system and the complexity of pharmaceutical issues in Mongolia, a sustainable process for the development of the adverse drug reaction reporting system is a key issue. The aim of this article is to disclose the Mongolian situation for the rest of the world and to share experiences on how an ADR reporting system can be developed towards a higher and more advanced level to contribute to both national and international drug safety issues. In this article, we review the features of the Mongolian health care and pharmaceutical systems, as well as the current development of the adverse drug reaction reporting system.

Educational Video Improves Knowledge about Outpatients' Usage of Antibiotics in Two Public Hospitals in Indonesia.

The inappropriate use or misuse of antibiotics, particularly by outpatients, increases antibiotic resistance. A lack of public knowledge about "Responsible use of antibiotics" and "How to obtain antibiotics" is a major cause of this. This study aimed to assess the effectiveness of an educational video about antibiotics and antibiotic use to increase outpatients' knowledge shown in two public hospitals in East Java, Indonesia. A quasi-experimental research setting was used with a one-group pre-test-post-test design, carried out from November 2018 to January 2019. The study population consisted of outpatients to whom antibiotics were prescribed. Participants were selected using a purposive sampling technique; 98 outpatients at MZ General Hospital in the S regency and 96 at SG General Hospital in the L regency were included. A questionnaire was used to measure the respondents' knowledge, and consisted of five domains, i.e., the definition of infections and antibiotics, obtaining the antibiotics, directions for use, storage instructions, and antibiotic resistance. The knowledge test score was the total score of the Guttman scale (a dichotomous "yes" or "no" answer). To determine the significance of the difference in knowledge before and after providing the educational video and in the knowledge score between hospitals, the (paired) Student's t-test was applied. The educational videos significantly improved outpatients' knowledge, which increased by 41% in MZ General Hospital, and by 42% in SG General Hospital. It was concluded that an educational video provides a useful method to improve the knowledge of the outpatients regarding antibiotics.

Candida Biofilm Formation Assay on Essential Oil Coated Silicone Rubber.

Development of biofilm associated candidemia for patients with implanted biomaterials causes an urgency to develop antimicrobial and biofilm inhibitive coatings in the management of recalcitrant Candida infections. Recently, there is an increase in the number of patients with biofilm formation and resistance to antifungal therapy. Therefore, there is a growing interest to use essential oils as coating agents in order to prevent biomaterial-associated Candida infections. Often high costs, complicated and laborious technologies are used for both applying the coating and determination of the antibiofilm effects hampering a rapid screening of essential oils. In order to determine biofilm formation of Candida on essential oil coated surfaces easier, cheaper and faster, we developed an essential oil (lemongrass oil) coated surface (silicone-rubber) by using a hypromellose ointment/essential oil mixture. Furthermore, we modified the "crystal violet binding assay" to quantify the biofilm mass of Candida biofilm formed on the lemongrass oil coated silicone rubber surface. The essential oil coating and the biomass determination of biofilms on silicone rubber can be easily applied with simple and accessible equipment, and will therefore provide rapid information about whether or not a particular essential oil is antiseptic, also when it is used as a coating agent.

Orodispersible films as a personalized dosage form for nursing home residents, an exploratory study.

Background A frequent problem in ageing patients, and thus in nursing home residents, is dysphagia, affecting the ability to swallow solid dosage forms. A promising and personalized drug delivery system for this patient group is the orodispersible film. Orodispersible films could be prepared extemporaneously in a (hospital) pharmacy setting or in specialty compounding community pharmacies using the solvent casting method. Little has been done to systematically investigate which medications should be chosen for orodispersible film formulation development. Objective In this study, the medication use of nursing home residents was examined to identify medications that are suitable for orodispersible film formulation development. Setting Nursing homes of three Northern provinces of Netherlands. Method Medication intake data from 427 nursing home residents from nine nursing homes from the three northern provinces of the Netherlands were used to identify candidates for orodispersible film formulation development. A stepwise approach, with exclusion steps, was used. Selection criteria included systemic use with a maximum amount of 100 mg per dose unit, no commercially available suitable dosage forms for administration in dysphagia, indication for diseases associated with dysphagia. Furthermore, the characteristics of the active pharmaceutical ingredient needed for the orodispersible film formulation development, such as water solubility and taste, were reviewed. Main outcome measure Active pharmaceutical ingredients suitable for orodispersible film formulation development. Results The nursing home residents used three hundred forty one different medications. Of those, 34 active pharmaceutical ingredients from six therapeutic groups were considered as candidates for orodispersible film formulation development. Most of these active pharmaceutical ingredients have a bitter taste and poor water solubility, which is a challenge for orodispersible film production. Conclusions The most suitable active pharmaceutical ingredient candidates for manufacturing of orodispersible films for the ageing patient population may be the combination of levodopa and carbidopa used to treat the symptoms of Parkinson's disease, and baclofen used to treat spasticity.

A Pediatrics Utilization Study in The Netherlands to Identify Active Pharmaceutical Ingredients Suitable for Inkjet Printing on Orodispersible Films.

BACKGROUND: The use of medication in pediatrics, children aged 0-5 years, was explored so as to identify active pharmaceutical ingredients (APIs) suitable for inkjet printing on a plain orodispersible film (ODF) formulation in a pharmacy. METHODS: The database IADB.nl, containing pharmacy dispensing data from community pharmacies in the Netherlands, was used to explore medication use in the age group of 0-5 years old, based on the Anatomical Therapeutic Chemical classification code (ATC code). Subsequently, a stepwise approach with four exclusion steps was used to identify the drug candidates for ODF formulation development. RESULTS: there were 612 Active Pharmaceutical Ingredients (APIs) that were dispensed to the target group, mostly antibiotics. Of the APIs, 221 were not registered for pediatrics, but were used off-label. After the exclusion steps, 34 APIs were examined regarding their suitability for inkjet printing. Almost all of the APIs were sparingly water soluble to practically insoluble. CONCLUSION: Pharmaceutical inkjet printing is a suitable new technique for ODF manufacturing for pediatric application, however the maximal printed dose as found in the literature remained low. From the selected candidates, only montelukast shows a sufficiently high water-solubility to prepare a water-based solution. To achieve higher drug loads per ODF is ambitious, but is theoretically possible by printing multiple layers, using highly water-soluble APIs or highly loaded suspensions.

pH-dependent ileocolonic drug delivery, part II: preclinical evaluation of novel drugs and novel excipients.

Novel drugs and novel excipients in pH-dependent ileocolonic drug delivery systems have to be tested in animals. Which animal species are suitable and what in vivo methods are used to verify ileocolonic drug delivery?

pH-dependent ileocolonic drug delivery, part I: in vitro and clinical evaluation of novel systems.

After the pH dependency of novel pH-dependent ileocolonic drug delivery systems is confirmed in vitro, their performance should be evaluated in human volunteers.