Dose accuracy

Constraints on nasal delivery include a restricted capacity (i.e., the volume of formulation that can be delivered is limited), attainment of dose accuracy, and the reproducibility of delivery. The distribution of drug in the nasal cavity is highly dependent on the delivery device, formulation, and administration technique. In turn, the distribution of drug will affect permeability, residence time, and metabolism in the nasal cavity. 

Since the device itself meters the dose, it must contain a precisely working measuring mechanism to ensure dose accuracy and consistency. The metering unit of the Turbuhaler consists of groups of truncated... 

Which quality attributes need to be built into the dosage form Dose accuracy, content uniformity, purity and stability are aspects to be evaluated, all of which are of particular interest to the scientist developing low-dose formulations. 

You might improve the dosing accuracy with a good scale and by presetting the dose. 

Figure 8-10 shows ideas that have been collected. There are two ideas to increase dosing accuracy a screw preset to fix the amount injected and a ratchet preset, where the piston is pulled out a certain distance beforehand. The force for pushing the fluid through the needle should not be too large even when very thin needles are used. There are two proposals for this using a screw and gears. 

Dosing accuracy of 0.1%. Accurate dosing of raw materials can save margarine producers significantly in the cost of ingredients. 

Griessmann K, Breitkreutz J, Schubert-Zsilavecz M, et al. Dosing accuracy of measuring devices provided with antibiotic oral suspensions. Paediatr Perinat Drag Ther 2007 10 61-70. 

Clarke A, Spollett G. Dose accuracy and injection force dynamics of a novel disposable insulin pen. Expert Opin Drug Deliv 2007 4 165-174. 

Some unique delivery devices are used in animal health as discussed later in this chapter. Knowing the compatibility of the formulation with these devices and whether any deleterious components are extracted from the devices is required. One example would be the rabber or silicone seals in oral drenching guns. Numerous manufactures of these guns exist, and each gun should be examined to be sure that as product contacts the seals those components are not removed that will either affect dosing accuracy and ease or be toxic to the animals receiving the product. 

Dose accuracy over time should be recorded this is done at the beginning, middle and end of delivery life for the product. This test is usually performed during the stability test programme to check dose accuracy at the end of shelf life. 

Particle-based formulations for pulmonary protein delivery request novel types of powder inhalers, which combine several attributes Kke the ability to apply rather high dosages of up to the milligram range. They need to exhibit high dose accuracy as well as to be even less dependent on the breath rate of the patient. 

The dose to be administered should also be measured. Also for this purpose the volume of the syringe to be used should be as close as possible to the required dose (volume). To achieve this, the injection fluid can be diluted, but when administered to neonates this is not common practice because fluid restriction in this patient group is more important than ultimate dose accuracy. In practice for example, a 1 mL syringe is preferably used for the administration of 0.6 mL (or even less), but a 2 mL syringe is taken if a 1 mL is unavailable. 

For the uniformity of content and dose accuracy. Particle size reduction increases the number of particles per tmit of weight and thereby the homogeneity of the mixture. 

It is the physical stability that determines the dosing accuracy of a suspension. To assure the quality of the final product, it is best to process just one dosage unit shortly before administration. 

Dosing accuracy in parenterals depends on the accuracy of the syringes used, the dead volume in the syringe (see Sect. 29.1.7) and what stays behind in the needle. This is important in the following manipulations ... 

The inclusion of nucleation inhibitors such as silicon dioxide can modulate nu-cleation process, thus prolonging the suspension stability. Particle size control of amorphous formulations is essential for homogeneity and withdrawability for dosing accuracy. 

Milled lactose particles of the size carrier particle. The carrier serves to increase the flow ability and dosing accuracy. It avoids agglomeration of APIs. In the mixture, the particles adhere to the surface of the carrier as single particles or small agglomerates. During the inhalation process, the API particles are separated from the carrier by impact and the carrier particle deposits within the pharynx. However, the surface of the milled particles is irregular and their size is characterized by a broad distribution. This may lead to uncontrolled disposal of the API [44]. 

In order to discuss the factors which affect the dosing accuracy it will be assumed that a pneumatically driven piston dosing pump is being used. The free cross sections of the piston dosing pump and pneumatic motor define the transmission ratio. For example, a transmission... 

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