Ear preparations

Special instructions for specific ear preparations are found in the Summary Drug Table Otic Preparations. When instilling ear drops, the nurse has die patient lie on his or her side with the ear toward the ceiling. If the patient wishes to remain in an upright position, the head is tilted toward the untreated side with the ear toward the ceiling (Fig. 57-1). hi the adult, the earlobe is pulled up and back. In children, the earlobe is pulled down and back. The nurse instills die prescribed number of drops into the ear canal. If die primary health... 

Pharmacists are also responsible for compounding special ear preparations for pets that are not commercially available. Sometimes the availability and cost of certain medications are prohibitive for a veterinarian s private pharmacy. 

Otic or ear preparations are usually very viscous so that they may have contact with the affected area. They can be employed to soften ear wax, relieve an earache, or combat an infection. 

Even when earefully prepared, model eolloids are almost never perfectly monodisperse. The spread in particle sizes, or polydispersity, is usually expressed as the relative width of the size distribution,... 

The formulation of ear drops, especially the choice of the vehicle, depends on the site of action the external auditory canal or the middle ear. When ear drops get to the middle ear, they may come into contact with the inner ear and so cause ototoxicity. Because of the ototoxicity of active substances, non-aqueous vehicles and many other excipients, special precautions are needed in formulations that should, or may accidentally, come into contact with the middle ear. Preparations intended for the middle ear are aqueous, sterile and preferably iso-osmotic. When non-aqueous vehicles are used in ear drops for the external auditory canal, it depends on the state of the patient s ear drum whether they will reach the middle ear. 

The Ph. Eur. states that Ear preparations (Auricularia) are liquid, semisolid or solid preparations intended for instillation, for spraying, for insufflation, or application to the auditory canal or as an ear wash. Ear preparations usually contain 1 or more active substances in a suitable vehicle. They may contain excipients to adjust tonicity or viscosity, to adjust or stabilise the pH, to increase the solubility of the active substances, to stabilise the preparation or to provide adequate antimicrobial properties. The excipients do not adversely affect the intended medicinal action of the preparation, or, at the concentrations used, cause toxicity or local irritation. 

Ear preparations are supplied in multidose or single-dose containers provided, if necessary, with a suitable... 

Unless otherwise justified, aqueous ear preparations supplied in multidose containers contain a suitable antimicrobial preservative at a suitable concentration, except where the preparation itself has adequate antimicrobial properties. An example of this is Bacicoline B . These ear drops contain a borate buffer, but no preservative. This was accepted by the licensing authorities because borate buffers have some antimicrobial properties and because the beyond-use date is 10 days after opening. 

Ear drops that may, or should reach the middle ear are sterile aqueous solutions, with a preservative added when they are supplied in multidose containers. The monograph Ear Preparations of the Ph. Eur. states that ear drops that may or should reach the middle ear, should be sterile and free from antimicrobial preservatives. That sterility is required seems clear, as the solvent in ear drops intended for the middle ear is water, and the middle ear has little defence because of its low blood flow. When preservatives are not to be used, such ear drops should be supplied in single-dose containers, unless otherwise justified. 

Ear drops are best stored at room temperature, provided the chemical and microbiological stability permit this. The reason is that administration of cold drops may cause dizziness (see Sect. 9.10). Ear preparations should only be stored refrigerated when this is absolutely necessary. 

The chief methods used to prepare esters m the laboratory were all described ear her and are summanzed m Table 20 3... 

Farmed animals tend to be subjected to compounds that can be classified more easily as drugs. In some cases, animals may encounter compounds in nature that have considerable limitations in inclusion in the diets of farmed animals. An example is the inclusion of zearalenone (Figure 1) and its derivatives in animal diets these have anabolic and oestrogenic properties " and are permitted to be used in some areas of the world but are prohibited from use in others, such as European Union countries. Thus this compound and its reduced isomers (zearalenols, zeranols) improve growth rates in animals but can cause reproductive problems, especially in pigs. Ralgro, which is a commercially prepared derivative of zearalenone, is used as an ear implant in beef cattle as a growth promoter in... 

Forced Circulation System—Using foreed eireulation in a waste heat reeovery system allows the use of smaller tube sizes with inherent inereased heat transfer eoeffieients. Flow stability eonsiderations must be addressed. The reeireulating pump is a eritieal eomponent from a reliability standpoint and standby (redundant) pumps must be eonsidered. In any event, great eare must go into preparing speeifieations for this pump. 

It is important to note diat antivertigo dragp are essentially antiemetics because many of these preparations, whedier used for motion sickness or vertigo, also have direct or indirect antiemetic properties. They prevent the nausea and vomiting diat occur because of stimulation of die vestibular apparatus in the ear. Stimulation of diis apparatus results in vertigo, which is often followed by nausea and vomiting. 

Various types of preparations are used for the treatment of otic (ear) disorders. Otic preparations can be divided into three categories (1) antibiotics (2) antibiotic and steroid combinations and (3) miscellaneous preparations. The miscellaneous preparations usually contain one or more of the following ingredients ... 

Otic preparations are instilled in the external auditory canal and may be used to relieve pain, treat infection and inflammation, and aid in the removal of earwax. When the patient has an inner ear infection, systemic antibiotic therapy is indicated. 

Before administration of an otic preparation, the primary health care provider examines the ear and external structures surrounding the ear and prescribes the drug indicated to treat the disorder. The nurse may be responsible for examining the outer structures of the ear, namely the earlobe and the skin around the ear. The nurse documents a description of any drainage or the presence of impacted cerumen. 

Promoting an Optimal Response to Therapy Before instillation of otic preparations, die nurse holds the container in the hand for a few minutes to warm it to body temperature. Cold and warm (above body temperature) preparations may cause dizziness or other sensations after being instilled into the ear. 

Educating the Patient and Family The nurse gives the patient or a family member instructions or a demonstration of the instillation technique of an otic preparation. The following information may be given to the patient when an ear ointment or solution is prescribed ... 

Only preparationslabeied as otic are instilled in the ear. The nurse must check the label of the preparation carefully for the name of the drug and a statement indicating that the preparation is for otic use. 

The patient demonstrates the ability to instill an otic preparation in the ear. 

The interest in hyperbranched polymers arises from the fact that they combine some features of dendrimers, for example, an increasing number of end groups and a compact structure in solution, with the ease of preparation of hn-ear polymers by means of a one-pot reaction. However, the polydispersities are usually high and their structures are less regular than those of dendrimers. Another important advantage is the extension of the concept of hyperbranched polymers towards vinyl monomers and chain growth processes, which opens unexpected possibilities. 

In contrast, parenteral suspensions have relatively low solids contents, usually between 0.5 and 5%, with the exception of insoluble forms of penicillin in which concentrations of the antibiotic may exceed 30%. These sterile preparations are designed for intramuscular, intradermal, intralesional, intraarticular, or subcutaneous injection. Syringeability is an important factor to be taken into consideration with injectable dosage forms. The viscosity of a parenteral suspension should be sufficiently low to facilitate injection. Common suspending vehicles include preserved isotonic saline solution or a parenterally acceptable vegetable oil. Ophthalmic and optic suspensions that are instilled into the eye/ear must also be prepared in a sterile manner. The vehicles are essentially isotonic and aqueous in composition. The reader should refer to Chapter 12 for further discussion on parenteral products. 

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