Preservative-free products

In-pack pasteurisation. In-pack pasteurisation is normally reserved for dilutable products that are made without preservatives. Unless there are particular circumstances that demand a preservative-free product (e.g. manufacture of a certified organic product), preservatives should always be used in dilutables because of the way the drinks are used and stored. A dilutable without preservatives is very vulnerable to microbial contamination, which can lead to fermentation and possibly bottle bursting. Dilutables without preservative must be labelled to encourage refrigerated storage and short shelf life. 

Tobramycin solution for inhalation has approval from the Food and Drug Administration (FDA) for maintenance therapy in patients with cystic fibrosis and who are colonized with Pseudomonas aeruginosa. The commercially available formulation is a 300 mg per 5mL. It is a sterile, preservative-free product that is pH adjusted to 6.0. According to the labeling, this product should be used with a specific nebulizer, the Pari C Plus. 

Intraocular irrigating solutions are required to be preservative-free to prevent toxicity to the internal tissues of the eye, particularly the corneal endothelium, lens, and retina [298,299]. These products are intended for single use only to prevent intraocular infections,... 

A new antiviral agent, developed for treatment of CMV retinitis, can be administered by intravitreal injection. Formivirsen sodium is a phosphorothioate oligonucleotide that inhibits CMV replication through an antisense mechanism. It is formulated as a sterile and preservative-free solution and supplied in single-use vials (Vitravene ). The product is administered directly into the vitreous cavity posterior to the limbus through a 30-gauge needle. This procedure can be performed on an... 

There is a small but growing market for high-value dilutables that are declared to be free from preservatives. These products must be adequately processed using in-bottle pasteurisation and the label clearly marked with the need for time-limited storage in refrigerated conditions. 

Temperature fluctuations can lead to condensation of moisture on the product and, with liquids, formation of a condensate layer on top of the product. This latter problem is well known and can lead to microbiological spoilage as the condensate is preservative free. 

Refresh products Carboxymethylcellulose preserved Offers preservative-free formulation... 

Genteal products (Novartis) Hydroxypropyl methylceUulose GenAqua is a disappearing preservative (sodium perborate) available in 0.2% drops (mild), 0.3% drops (moderate), and 0.3% gel (severe) formulations as well as 0.3% single-use preservative-free vials contacts may be inserted 15 minutes after drop instUlation. 

Route of administration. The USP, EP, and BP do not allow preservatives to be present in injections intended to come in contact with brain tissues or CSF. Thus intracisternal, epidural, and intradural injections should be preservative free. Also, it is preferred that a drug product to... 

The antibacterial and antifungal properties of organomercurials have resulted in their long-term use as topical disinfectants (thimerosal and merbro-min) and preservatives in medical preparations (thimerosal) and grain products (both methyl and ethyl mercurials). Phenylmercury has been used in the past in paints, and dialkyl mercurials are still used in some industrial processes and in the calibration of certain analytical laboratory equipment. A major issue in recent years has been the presence of mercury in some vaccines, for example, in the vaccine preservative thimerosal - this has led to suspension of some vaccination programs and the development of preservative-free (i.e., mercury-free) vaccines as replacements. 

Knudsen numbers signify the coexistence of both mechanisms. Fickian diffusion is significantly slower than Knudsen diffusion at the same vapor pressure gradient. Experimental measurements of water flux in the presence and absence of air in the pores have shown a two to three-fold increase on degassing. Lowering the total gas pressure in the pores decreases the frequency of water vapor-air collisions, and thereby increases the mean free path of the water molecules. However, feed pretreatment by heating or exposure to a vacuum to remove air is often counterproductive to the preservation of product quality. 

Osmotic distillation is a relatively new membrane separation process, which is used primarily for the dewatering of liquid food products. The majority of reported applications have involved the production of fruit juice concentrates. The main advantage of OD over vacuum distillation, which is the conventional method for concentrate production, is the preservation of product integrity. Osmotic distillation is operated at mild temperatures (typically ambient), and thereby produces concentrates that are free from the effects of thermal degradation. Also, the delicate volatile flavor and fragrance components that are essential to consumer acceptance of fruit juice concentrates are largely retained. 

In summary, although there is considerable evidence that parabens can penetrate into the skin, permeation and systemic availability of intact compounds are likely to be considerably reduced by transcutaneous and systemic metabolism. Furthermore, since these preservatives are present at concentrations of 0.1-0.2 percent w/w in topical pharmaceutical formulations, in-use dermal exposure to these compounds will be relatively low. In the cosmetic industry, there is a trend toward preservative-free and self-preserving formulations (Kabara and Orth 1997). However, before starting down this road, the pharmaceutical formulator must consider the potential implications on the efficacy and safety of the product. 

The marketed products are formulated as a sterile, colorless, preservative-free liquid for intravenous or subcutaneous administration. The vial should not be shaken, or the glycoprotein may become denatured, rendering it inactive. Epoetin alpha is indicated for the treatment of various anemias. Several of the conditions are listed in Table 6.4. Epoetin alpha represents a major scientific advance in the treatment of patients with chronic renal failure, serving as a replacement therapy for inadequate production of endogenous EPO by failing kidneys. Epoetin alpha may decrease the need for infusions in dialysis patients. By several mechanisms related to elevating the erythroid progenitor cell pool, epoetin alpha increases the production of red blood cells. 

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