Spraying dose control systems

Desmopressin may be given orally, intranasally, SC, or IV. The oral dose must be determined for each individual patient and adjusted according to the patient s response to therapy. When the drug is administered nasally, a nasal tube is used for administration. The nasal tube delivery system comes with a flexible calibrated plastic tube called a rhinyle. The solution is drawn into the rhinyle. One end is inserted into the nostril and the patient (if condition allows) blows the other end to deposit solution deep into the nasal cavity. A nasal spray pump may also be used. Most adults require 0.2 mL daily in two divided doses to control diabetes insipidus. The drug may also be administered via the SC route or direct IV injection. 

The effects of budesonide aqueous nasal spray (64 micrograms/day) on adrenal function were studied in a 6-week double-blind, placebo-controlled study in 78 patients with allergic rhinitis aged 2-5 years (39). Adrenal function, evaluated by the mean change in morning plasma cortisol concentration after cosyntropin stimulation, was not suppressed. This dose of budesonide by nasal spray is unlikely to have significant systemic activity. 

Agricultural crop sprayers employ one of two methods for controlling the dose of a spraying system travelling at a defined or measured forward speed, namely ... 

Methods by which dose and mixtures of spray chemicals can be delivered at different controlled rates have been discussed earlier in this section. For spatially variable (patch) applications, Miller et al. (1997) summarised the performance requirements of the application system as follows ... 

It is stated that nasal sprays have unique characteristics with respect to formulation, container closure system, manufacturing, in-process and final controls and stability. The product must deliver reproducible doses during the whole life of the product. Excipient controls are discussed in the FDA draft guidance in many respects, the chemistry, manufacturing and controls (CMC) standards expected of excipients are starting to approach those required of the active pharmaceutical ingredient (API). 

Controlled release of agrochemicals (e.g., by hydrolysis of a polymeric ester) can offer the advantages of constant level, smaller dose, reduced evaporation loss, lower toxicity, longer life, decreased environmental pollution, and reduced effect on nontarget species by wind or runoff.20 Systemic pesticides are preferred. This ensures protection of the growing tip of the plant. For weed killers, this means that it is not necessary to hit every leaf of the plant with the herbicide. Pesticides are often applied on a spray schedule according to the calendar as a prophylactic measure. Chemical pesticides are used 98% of the time. 

The delivery is based on the piezoelectric fluid ejection system, which monitors every application of a drug. Using sophisticated technology, the system is able to control the dosing and ejection of micro-droplets to enable direct application on the ocular surface. It can be used across a platform of topical medications. Glaucoma, antibiotic, and mydriatic drops have been successfully sprayed using this delivery system. 

---