Effectiveness of ophthalmic solution preservatives: a comparison of latanoprost with 0.02% benzalkonium chloride and travoprost with the sofZia preservative system

<p>Abstract</p> <p>Background</p> <p>Although in vitro and in vivo laboratory studies have suggested that benzalkonium chloride (BAK) in topical ophthalmic solutions may be detrimental to corneal epithelial cells, multiple short- and long-term clinical studies have provided evidence supporting the safety of BAK. Despite the conflicting evidence, BAK is the most commonly used preservative in ophthalmic products largely due to its proven antimicrobial efficacy. This study was designed to characterize the antimicrobial performance of two commonly used topical ocular hypotensive agents that employ different preservative systems: latanoprost 0.005% with 0.02% BAK and travoprost 0.004% with sofZia, a proprietary ionic buffer system.</p> <p>Methods</p> <p>Each product was tested for antimicrobial effectiveness by <it>European Pharmacopoeia </it>A (EP-A) standards, the most stringent standards of the three major compendia, which specify two early sampling time points (6 and 24 hours) not required by the <it>United States Pharmacopeia </it>or <it>Japanese Pharmacopoeia</it>. Aliquots were inoculated with between 10⁵and 10⁶colony-forming units of the test organisms: <it>Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Candida albicans </it>and <it>Aspergillus brasiliensis</it>. Sampling and enumeration were conducted at protocol-defined time points through 28 days.</p> <p>Results</p> <p>BAK-containing latanoprost met EP-A criteria by immediately reducing all bacterial challenge organisms to the test sensitivity and fungal challenges within the first six hours while the preservative activity of travoprost with sofZia did not. Complete bacterial reduction by travoprost with sofZia was not shown until seven days into the test, and fungal reduction never exceeded the requisite 2 logs during the 28-day test. Travoprost with sofZia also did not meet EP-B criteria due to its limited effectiveness against <it>Staphylococcus aureus</it>. Both products satisfied United States and Japanese pharmacopoeial criteria.</p> <p>Conclusions</p> <p>Latanoprost with 0.02% BAK exhibited more effective microbial protection than travoprost with sofZia using rates of microbial reduction, time to no recovery for all challenges and evaluation against EP-A criteria as measures. The rapid and complete reduction of all microbial challenges demonstrates that antimicrobial activity of latanoprost with 0.02% BAK exceeds that of travoprost with sofZia preservative system in these products and provides a more protective environment in the event of contamination and subsequent exposure to microorganisms during use.</p

A systematic review of the use of dosage form manipulation to obtain required doses to inform use of manipulation in paediatric practice

This study sought to determine whether there is an evidence base for drug manipulation to obtain the required dose, a common feature of paediatric clinical practice. A systematic review of the data sources, PubMed, EMBASE, CINAHL, IPA and the Cochrane database of systematic reviews, was used. Studies that considered the dose accuracy of manipulated medicines of any dosage form, evidence of safety or harm, bioavailability, patient experience, tolerability, contamination and comparison of methods of manipulation were included. Case studies and letters were excluded. Fifty studies were eligible for inclusion, 49 of which involved tablets being cut, split, crushed or dispersed. The remaining one study involved the manipulation of suppositories of one drug. No eligible studies concerning manipulation of oral capsules or liquids, rectal enemas, nebuliser solutions, injections or transdermal patches were identified. Twenty four of the tablet studies considered dose accuracy using weight and/or drug content. In studies that considered weight using adapted pharmacopoeial specifications, the percentage of halved tablets meeting these specifications ranged from 30% to 100%. Eighteen studies investigated bioavailability, pharmacokinetics or clinical outcomes following manipulations which included nine delayed or modified release formulations. In each of these nine studies the entirety of the dosage form was administered. Only one of the 18 studies was identified where drugs were manipulated to obtain a proportion of the dosage form, and that proportion administered. The five studies that considered patient perception found that having to manipulate the tablets did not have a negative impact on adherence. Of the 49 studies only two studies reported investigating children. This review yielded limited evidence to support manipulation of medicines for children. The results cannot be extrapolated between dosage forms, methods of manipulation or between different brands of the same drug

Scientific Opinion on the safety and efficacy of niacin (nicotinic acid and nicotinamide) as a feed additive for all animal species based on a dossier submitted by Lonza Benelux BV

&lt;p&gt;The term ‘niacin’ is used as a generic description of nicotinic acid and nicotinamide with pyridine as the basic structure. Nicotinic acid and nicotinamide function mainly as precursors of the co-enzymes NAD and NADP. Thus, nicotinamide has physiologically critical roles in mitochondrial respiration and in the metabolism of carbohydrates, lipids, and amino acids. Oral administration routes of nicotinic acid and nicotinamide via feed or water for drinking were considered bioequivalent. Niacin is safe for the target animals with a margin of safety that is at least ten times the requirements and use levels. The FEEDAP Panel assumes that exposure figures for a population already include the contribution of edible tissues and products of animals fed niacin-supplemented diets. Information on niacin metabolism and the limited data available on retention in edible tissues and products indicate that supplemental levels in feeds even far higher than the requirements (1–35 mg/kg feed) are highly unlikely to lead the tolerable upper intake level being exceeded. The FEEDAP Panel considers that the use of niacin in animal nutrition is not of safety concern for consumers. Nicotinic acid and nicotinamide are not irritant to skin, but can cause irritancy to eyes and mucous membranes. They are unlikely to cause skin sensitisation. Workers might be exposed to a respirable dust when handling nicotinic acid, which should be regarded as being potentially harmful to their health. Nicotinamide is considered to be of no concern for inhalation exposure. The use of nicotinic acid and nicotinamide in animal nutrition does not pose a risk to the environment. Nicotinic acid and nicotinamide are regarded as effective sources of niacin in animal nutrition.&lt;/p&gt