Els Adriaens

A proposed eye irritation testing strategy to reduce and replace in vivo studies using Bottom–Up and Top–Down approaches

In spite of over 20 years of effort, no single in vitro assay has been developed and validated as a full regulatory replacement for the Draize Eye Irritation test. However, companies have been using in vitro methods to screen new formulations and in some cases as their primary assessment of eye irritation potential for many years. The present report shows the outcome of an Expert Meeting convened by the European Centre for the Validation of Alternative Methods in February 2005 to identify test strategies for eye irritation. In this workshop test developers/users were requested to nominate methods to be considered as a basis for the identification of such testing strategies. Assays were evaluated and categorized based on their proposed applicability domains (e.g., categories of irritation severity, modes of action, chemical class, physicochemical compatibility). The analyses were based on the data developed from current practice and published studies, the ability to predict depth of injury (within the applicable range of severity), modes of action that could be addressed and compatibility with different physiochemical forms. The difficulty in predicting the middle category of irritancy (e.g. R36, GHS Categories 2A and 2B) was recognized. The testing scheme proposes using a Bottom-Up (begin with using test methods that can accurately identify non-irritants) or Top-Down (begin with using test methods that can accurately identify severe irritants) progression of in vitro tests (based on expected irritancy). Irrespective of the starting point, the approach would identify non-irritants and severe irritants, leaving all others to the (mild/moderate) irritant GHS 2/R36 categories.

Home Medication Cabinets and Self-Medication: A Source of Potential Health Threats?

BACKGROUND: Data regarding the contents of home medication cabinets (HMCs), the management of leftover medications, and the inclination of patients toward self-initiated treatment using nonprescription drugs are scarce. OBJECTIVE: To evaluate the nature and safety of medication storage and intended self-medication in a general population. METHODS: A cross-sectional study was conducted in 72 Belgian community pharmacies. Pharmacy customers (N = 288, aged 18–80 y) were visited in their homes by pharmacy students. The HMCs were inventoried and the participants were interviewed. RESULTS: A mean of 31 ± 17 (range 6–136) drug packages were identified per household; in one-third of the cases, the packages were not stored safely. Prescription drugs accounted for 34% of the total. The most frequently encountered categories of registered medicines were nonopioid analgesics (7.2%), nonsteroidal antiinflammatory drugs (NSAIDs) (6.9%), nasal decongestants (3.5%) and antinausea agents (3.2%). Despite their high prevalence, NSAIDs and non-opioid analgesics did not predominate among the most frequently used drugs, whereas food supplements were used daily in 23.3% of households. Twenty-one percent of the drugs were expired, 9% were not stored in the original container, and the package insert was missing for 18%. Self-initiated treatment was considered for 56% of all drugs (over-the-counter drugs, 74%; prescription drugs, 21%). Indication, dosage, or treatment duration was misjudged by only 5.2% of the participants, but consulting the package insert was allowed. The tendency toward self-treatment decreased with age and with increasing number of medications taken daily (p = 0.002). CONCLUSIONS: We found large amounts of drugs per household, with a high prevalence of analgesics and NSAIDs. Self-medication, although generally acceptable in terms of indication and dosage, was commonly practiced, also with prescription drugs. Taking into account that younger people showed a significantly higher intention of self-medication, a sustained awareness of the risks of self-medication is warranted for the future.

Toxicological evaluation of a bioadhesive nasal powder containing a starch and Carbopol® 974 P on rabbit nasal mucosa and slug mucosa

The purpose of this study is the investigation of possible adverse effects of a powder formulation containing drum-dried waxy maize (DDWM) starch and Carbopol 974 P (90/10) on the nasal mucosa of rabbits and the foot mucosa of slugs after multiple administrations. In the rabbit, the effect of the formulation was measured by the release of proteins and lactate dehydrogenase (LDH) from the nasal mucosa with a new non-invasive in vivo method and also by histopathology. The mucosal toxicity of the formulation was evaluated using slugs by measuring the effect on the body weight and the amount of mucus produced during a repeated contact period. Additionally, the release of proteins, lactate dehydrogenase and alkaline phosphatase from the body wall of the slugs after a repeated treatment was measured. Twenty four hours after the powder administration to the rabbits the release of the marker molecules was comparable with the negative controls. The histopathological study showed only a slight increase of granulocytes in the epithelium. The formulation induced a higher mucus production in the slugs but no additional effects were detected on the body weight and on the release of proteins. No enzymes were released from the body wall. The results indicate that the effect of the bioadhesive powder consisting of DDWM/Carbopol 974 P (90:10, w/w) on the mucosa was negligible.

Development of injection moulded matrix tablets based on mixtures of ethylcellulose and low-substituted hydroxypropylcellulose

The objective of this study was to produce sustained-release matrix tablets by means of injection moulding and to evaluate the influence of matrix composition, process temperature and viscosity grade of ethylcellulose on processability and drug release by means of a statistical design. The matrix tablets were physico-chemically characterized and the drug release mechanism and kinetics were studied. Formulations containing metoprolol tartrate (30%, model drug), ethylcellulose with dibutylsebacate (matrix former and plasticizer) and L-HPC were extruded and subsequently injection moulded into tablets (375mg, 10mm diameter, convex-shaped) at different temperatures (110, 120 and 130 degrees C). Dissolution tests were performed and tablets were characterized by means of DSC, X-ray powder diffraction studies, X-ray tomography, porosity and hardness. Tablets containing 30% metoprolol and 70% ethylcellulose (EC 4cps) showed an incomplete drug release within 24h (<50%). Formulations containing L-HPC and EC in a ratio of 20/50 and 27.5/42.5 resulted in nearly zero-order drug release, while the drug release rate was not constant when 35% L-HPC was included. Processing of these formulations was possible at all temperatures, but at higher processing temperatures the drug release rate decreased and tablet hardness increased. Higher viscosity grades of EC resulted in a faster drug release and a higher tablet hardness. The statistical design confirmed a significant influence of the EC and L-HPC concentration on drug release, while the processing temperature and EC viscosity grade did not affect drug release. Tablet porosity was low (<5%), independent of the formulation and process conditions. DSC and XRD demonstrated the formation of a solid dispersion. The hydration front in the tablets during dissolution was visualized by dynamic X-ray tomography, this technique also revealed an anisotropic pore structure through the tablet.

Mucosal irritation potential of personal lubricants relates to product osmolality as detected by the slug mucosal irritation assay.

Background: The slug mucosal irritation assay has recently been used as a sensitive measure of mucus membrane tolerance for vaginal microbicide products and carriers. In the current study, it was determined whether musosal irritation potency of personal lubricants is related to varying product osmolalities. Methods: Five commercial lubricants with an osmolality range were evaluated using the previously validated slug mucosal irritation assay. Specifically, Arion lusitanicus were treated with lubricants over 5 days to quantify mucus production and tissue damage, allowing assignment of each product into an irritation potency category (none, mild, moderate, or severe). Results: The irritation potency (assessed by the mucus production) of the lubricants showed a significant, quadratic relationship with the product osmolality (P = 0.001; R2 = 0.99). Femglide, a hypo-osmotic lubricant (32 mOsm/kg), caused a negative mucus production. Pré, an iso-osmotic lubricant (316 mOsm/kg), caused no changes. Two moderately hyperosmotic lubricants, Replens and K-Y jelly (2143 and 2463 mOsm/kg), induced mild and moderate irritation, respectively. The highly hyperosmotic lubricant Astroglide (5848 mOsm/kg) resulted in severe irritation and tissue damage. Conclusions: Commonly used personal lubricants show a full range of mucosal irritation potential, which is related to product osmolality.

Evaluation of a mucoadhesive tablet for ocular use

The present study investigates the use of a polymer mixture containing Carbopol 974P and drum dried waxy maize starch to obtain prolonged drug release to the anterior eye segment. Two dosage forms with this composition are compared: a hydrated polymer dispersion and a minitablet. A model fluorescent tracer is used to study the ocular release and diffusion from the two dosage forms in humans. To evaluate the prolongation in the cornea/tearfilm compartment, the Apparent Fluorescein TurnOver (%/min) is calculated. The parameters Cmax, tmax, and C9h are used to characterize the pharmacokinetics of Na-fluorescein in the anterior chamber. Furthermore, the swelling behavior of the minitablet is evaluated macroscopically, while the degree of interaction with mucin is characterized by rheological measurements. Calculation of an acceptability score and a slug irritation potential is performed to evaluate user acceptability. In contrast to the hydrated dispersion, the minitablet significantly decreases the Apparent Fluorescein TurnOver (%/min) (P<0.05) and increases the apparent fluorescence in the anterior chamber 9 h after application of the preparation. Rheological data demonstrate the presence of elastic interactions between the polymer and mucin. The dry core of the minitablet becomes fully hydrated after approximately 2 h and is subsequently transformed into a highly concentrated gel. The acceptability of the minitablet is comparable to that of the polymer dispersion. Prolonging the release of Na-fluorescein to the anterior eye segment is only feasible with the dry preparation.

Gastropods as an Evaluation Tool for Screening the Irritating Potency of Absorption Enhancers and Drugs

AbstractPurpose. The objective of this study was to develop a simple alternative test using naked snails (slugs) for screening the irritating potency of chemicals on mucosal surfaces. Methods. The effect of various absorption enhancers and two β-blocking agents on the mucosal tissue was determined from the total protein and lactate dehydrogenase released from the foot mucosa after treatment. Additionally, mucus production and reduction in body weight of the slugs caused by the treatment were measured. Results. According to the effects on the mucosal epithelium of the slugs the following rank order of increasing toxicity was established: PBS, HP-β-CD (5%), β-CD (1.8%) and oxprenolol hydrochloride (1 %) < DDPC (l%) < STDHF (l%) < BAC (l%), SDC (l%) and propranolol hydrochloride (1 %). The results of the present study are in agreement with other studies using the same compounds on other models. Conclusions. The results of this study indicated the mucosa of slugs can serve as a primary screening tool for the evaluation of chemicals on mucosal surfaces. By simply measuring mucus production and weight loss reliable toxicity information can be obtained. This demonstrates rapid screening tests can be carried out using simple toxicity endpoints.

Effectiveness of pharmaceutical care for patients with chronic obstructive pulmonary disease (PHARMACOP): a randomized controlled trial

AIMS Few well-designed randomized controlled trials have been conducted regarding the impact of community pharmacist interventions on pharmacotherapeutic monitoring of patients with chronic obstructive pulmonary disease (COPD). We assessed the effectiveness of a pharmaceutical care programme for patients with COPD. METHODS The pharmaceutical care for patients with COPD (PHARMACOP) trial is a single-blind 3 month randomized controlled trial, conducted in 170 community pharmacies in Belgium, enrolling patients prescribed daily COPD medication, aged ≥ 50 years and with a smoking history of ≥ 10 pack-years. A computer-generated randomization sequence allocated patients to an intervention group (n = 371), receiving protocol-defined pharmacist care, or a control group (n = 363), receiving usual pharmacist care (1:1 ratio, stratified by centre). Interventions focusing on inhalation technique and adherence to maintenance therapy were carried out at start of the trial and at 1 month follow-up. Primary outcomes were inhalation technique and medication adherence. Secondary outcomes were exacerbation rate, dyspnoea, COPD-specific and generic health status and smoking behaviour. RESULTS From December 2010 to April 2011, 734 patients were enrolled. Forty-two patients (5.7%) were lost to follow-up. At the end of the trial, inhalation score [mean estimated difference (Δ),13.5%; 95% confidence interval (CI), 10.8-16.1; P < 0.0001] and medication adherence (Δ, 8.51%; 95% CI, 4.63-12.4; P < 0.0001) were significantly higher in the intervention group compared with the control group. In the intervention group, a significantly lower hospitalization rate was observed (9 vs. 35; rate ratio, 0.28; 95% CI, 0.12-0.64; P = 0.003). No other significant between-group differences were observed. CONCLUSIONS Pragmatic pharmacist care programmes improve the pharmacotherapeutic regimen in patients with COPD and could reduce hospitalization rates.

Partial hydrolysis of poly(2-ethyl-2-oxazoline) and potential implications for biomedical applications?

The hydrolysis of PEtOx is studied to evaluate the potential toxicity of partially hydrolyzed polymers that might interfere with its increasing popularity for biomedical applications. The hydrolysis of PEtOx is studied in the presence of digestive enzymes (gastric and intestinal) and at 5.8 M hydrochloric acid as a function of temperature (57, 73, 90, and 100 °C). It is found that PEtOx undergoes negligible hydrolysis at 37 °C and that thermal and solution properties are not altered when up to 10% of the polymer backbone is hydrolyzed. Mucosal irritation and cytotoxicity is also absent up to 10% hydrolysis levels. In conclusion, PEtOx will not decompose at physiological conditions, and partial hydrolysis will not limit its biomedical applications.

COPD Management in Primary Care: An Observational, Community Pharmacy–Based Study

Background: Chronic obstructive pulmonary disease (COPD) is a prevalent disease that is frequently treated in primary care. However, data regarding the primary care management of COPD are scarce. Such observational data are necessary to detect problem areas and to develop targeted interventions for improvement of COPD management. Objective: To provide a detailed description of (1) drug therapy, (2) drug adherence, (3) inhalation technique, and (4) health status of patients with COPD recruited via community pharmacies. Methods: A cross-sectional, observational study was conducted in 93 pharmacies in Belgium. Participants (N = 555) completed a questionnaire collecting information on personal characteristics, smoking history, influenza vaccination, COPD medication, and adverse effects. Adherence to COPD maintenance medication was analyzed 1 year retrospectively through prescription refill rates. Inhalation technique was scored using a checklist. Health status was evaluated with the St. Georges Respiratory Questionnaire, the Clinical COPD Questionnaire, and the Modified Medical Research Council dyspnea scale. Results: The mean age of the patients was 68.6 years; 73.7% were men and 37.2% were current smokers. The influenza vaccination status was significantly lower in patients aged less than 65 years (65.7%) than in patients aged 65 years or more (86.2%) (p < 0.001). Fixed combinations of inhaled corticosteroids and long-acting β2-agonists were the most frequently used COPD medications (75.4%). About 48% of patients were underadherent (<80% adherence), 47% were adherent (80–120% adherence) and 5% were overadherent (>120% adherence). Predictors for underadherence were age and number of drugs. Twenty-one percent of patients made major inhalation technique errors with rescue medication; these were all errors in handling pressurized metered-dose inhalers (pMDIs). Conclusions: This observational study on COPD management in primary care highlights 4 main aspects that could be improved: (1) drug adherence, (2) inhalation technique with pMDIs, (3) influenza vaccination in COPD patients younger than 65 years, and (4) smoking cessation.