Instillation route

The instillation route consists of administering medication by drops, ointments, or sprays. Special care must be taken to prevent the spread of the disease when instilling the medication. When administering medication to the eye using the instillation route ... 

When administering medication to the ear using the instillation route ... 

When administering medication to the nose using the instillation route, first ask the patient to blow his or her nose. When instilling nose drops ... 

Medication that you place in your eyes, ears, or in your nose is administered using the instillation route in the form of drops, ointment, and sprays. Patients with lung problems sometimes receive medication using the inhalation route. Medication is delivered using an inhaler that changes liquid medication into a spray. 

C]taurine-labeled MWNTs were administered to mice by three different exposure routes (intravenous injection, gavage, and intratracheal instillation) and their biodistribution was monitored [134], After intravenous injection, [14C]taurine-labeled MWNTs accumulated in the liver, heart, and lung after gavage administration, [14C]taurine-labeled MWNTs was only detectable in the stomach, intestine, and feces. No [14C]taurine-labeled MWNTs were detected in the blood. Finally, [14C] taurine-labeled MWNTs were partly cleared from the lungs after intratracheal instillation. Since various cell and tissue types have demonstrated a high affinity for uptake of taurine, it should be noted that the label used in this investigation may have influenced the biodistribution of the MWNTs tested [101]. 

With increased meningeal inflammation, there will be greater antibiotic penetration (Table 36-3). Problems ofCSF penetration maybe overcome by direct instillation of antibiotics by intrathecal, intracisternal, or intraventricular routes of administration (Table 36-4). 

Uses (routes) Dermal and oral. Not preferred for oral volume of instillation should be limited to 5 m I kg 1 by the oral route... 

In rats exposed by intratracheal instillation to radiolabeled phenol, elimination was 95% complete after 72 hours, with the primary elimination route being through the urine (Hughes and Hall 1995). Fecal elimination was slower and accounted for less overall. 

The ocular route is used mainly for the local treatment of eye pathologies. Absorption of drugs administered by conventional eyedrops can result in poor ocular bioavailabilities (2-10%). This is due to the limited area of absorption, the lipophilic character of the corneal epithelium, and a series of elimination factors that reduce the contact time of the medication with the comeal surface, such as drainage of instilled solutions, lacrimation, and tear turnover and tear evaporation [56]. 

Other routes of administration can be employed in certain situations. Methotrexate and cytarabine are given intrathecally or intraventricularly to prevent relapses in the meninges in acute lymphocytic leukemia and to treat carcinomatous meningitis. Thiotepa and bleomycin have been administered by intravesical instillation to treat early bladder cancers. Fluorouracil can be applied topically for certain skin cancers. 

The routes of delivery of rAAV in animal models have been largely based upon the specific needs dictated by the disease process to be treated. For example, rAAV-cystic fibrosis transmembrane conductance regulator (CFTR) vectors that have been developed for treatment of cystic fibrosis (CF) were tested in New Zealand white rabbits and in rhesus macaques by the endobronchial route (Flotte et al., 1993 Afione et al., 1996 Conrad et al., 1996). In each instance aliquots of vector were instilled directly into the lumen of a bronchus through a fiberoptic bronchoscope. Vector DNA transfer and mRNA expression were detectable (albeit at low levels) for more than 6 months in each instance, without any indication of inflammation or any other toxicity. Studies in rhesus monkeys also indicated that the likelihood of rescue of rAAV by concomitant wild-type AAV and adenovirus infection was low. These studies... 

The model was developed from several data sets in which rats were dosed with chromium(VI) or chromium(III) intravenously, orally, or by intratracheal instillation, because depending on route of administration, different distribution and excretion patterns occur. In cases where parameters were not available (absorption rates, tissue affinity, biotransformation), estimates were obtained by fitting. This was done by duplicating the initial conditions of published experiments in the model, varying the unknown parameters and comparing the results of the simulation to the reported results. Tissue affinity constants were estimated using reported chromium levels in tissues at various times after exposure. 

There are two pathways for ocular absorption, the corneal route and the conjunctiva/scleral route as shown in Figure 12.3. Conjunctival absorption is nonproductive and constitutes an additional loss following instillation of a topical dose. 

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