Spray weight

A test to assess pump-to-pump reproducibility in terms of drug product performance and to evaluate the delivery from the pump should be performed. The proper performance of the pump should be ensured primarily by the pump manufacturer, who should assemble the pump with parts of precise dimensions. Pump spray weight delivery should be verified by the applicant for the drug product. In general, pump spray weight delivery acceptance criteria should con-... 

As with other packaging components, the incoming tests and specifications of metered valves, inspection attributes, and AQLs (acceptable quality levels) will need to be coordinated with the supplier. The valve should be considered as a critical package component and have incoming performance tests, such as spray weights and weight loss [13,14], The performance test could be conducted on a sample of the valve lots from either scale-up or pilot trials before the validation lots are prepared. This information may also be available for each lot from the supplier. It is recommended that each test shown in Table 3 be conducted on at least three valve lots as part of the validation program. 

Valve delivery (spray weights), 40 Meter chamber size, in-use test,... 

It is imperative to also consult the vendor to determine an adequate number of valves for spray weight testing. If the metered chamber is plastic, valves totaling at least twice the number of the vendor s mold impressions should be tested to guarantee complete evaluation of the lot of valves. The spray weight methodology conducted on valves can drastically influence the results. Because the valve is a mechanical device, the way in which it is actuated is technique-oriented. Manual actuation versus automatic actuation can cause variation in the results. Method ruggedness is essential in evaluation of the valve performance. 

Various studies (Bond et al. 1984 Newman et al. 1987a) have found droplet size distributions of aqueous nasal spray products to have mass mean (median) diameter values between 44 and 62 pun. These studies showed that the majority of the dose was deposited locally in the anterior one-third of the nose. The relationship between retention time and viscosity has shown that the addition of various concentrations of methylcellulose (MC) to a metered spray pump containing desmopressin resulted in a dose-related increase in mean particle size from 51 pan (0 percent MC) to 81 pan (0.25 percent MC) to 200 pirn (0.5 percent MC), without a change in mean spray weight. The longest retention time was observed for the 0.25 percent MC solution, which was attributed to its particle size (81 p,m) and not to an increase in viscosity, since a decrease in retention time was observed for the highest viscosity (0.5 percent MC) solution... 

Spray Weight Droplet Size and Spray Angle... 

It is important for data on nasal sprays to include the following (a) spray weight variation (important to measure the amount of drug reaching the patient), (b) droplet size distribution and (c) spray angle. Spray weight is volume dependent and is effectively a measure of the amount... 

In addition to the fundamental testing of spray weight, droplet size and spray angle, there are a variety of additional tests to be performed as part of the development process. 

Chemical binders are appHed to webs in amounts ranging from about 5 to 60 wt %. In some instances when clays (qv) or other weight additives ate included, add-on levels can approach or even exceed the weight of the web. Waterborne binders ate appHed by spray, saturation, print, and foam methods. A general objective of each method is to apply the binder material in a manner sufficient to interlock the fibers and provide chemical and mechanical properties sufficient for the intended use of the fabfic. 

AATCC methods for determining water repeUency are AATCC 22 (spray test) and AATCC 70 (tumble jar dynamic absorption test). In the spray test, water is sprayed against the taut surface of the test specimen to produce a wetted pattern the size of which depends on the repeUency of the fabric. Evaluation is by comparing the pattern with a series of patterns on a standard chart. The latter method evaluates the percentage by weight of water absorbed by a sample after dynamic exposure to water for a specified period of time. 

Water resistance test methods include AATCC 127 (hydrostatic pressure test), AATCC 42 (impact penetration test), and AATCC 35 (rain test). In the hydrostatic pressure test, a sample is subjected to a column of increasing water pressure until leakage occurs. The impact penetration test requires water to be sprayed on the taut surface of a fabric sample from a height of two feet. The fabric is backed by a blotter of predeterrnined weight, which is reweighed after water penetration. The rain test is similar in principle to the impact penetration test. 

As shown in Figure 6, desirable fixative properties superior to PVP homopolymer can be specified by judicious selection of the amount of vinyl acetate. Hair sprays are limited in the molecular weight of the resin because if they are too high the resulting viscosity of the formulation will result in a poor (coarse) spray pattern. Increasing the VP/VA ratio causes properties to increase in the direction shown by the arrows. 

SUicones are suppUed as aqueous emulsions or as solvent solutions. Dow-Coming and OSi Specialties are primary manufacturers and suppUers. Emulsions are usuaUy appUed to fabrics by pa dding or exhaustion. Solvent solutions can be appUed by spraying. With either type of product, coappUcation of a catalyst is necessary. The level of sUicone soUds on the weight of fabric should be 0.5—1.5%. Most of the sUicone emulsions can be coappUed with durable-press resins. Curing occurs at about 150°C. 

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