Oral liquids suspensions

Liquid medicines generally include oral liquids, suspensions, emulsions, inhalations, nasal solutions and suspensions, topical semisolids and topical liquids, ophthalmics, and parenterals. There are numerous excipients used for liquid... 

Solid oral dosage forms, particularly tablets, are the preferred type of formulation in the United States. Not only are these products widely accepted by consumers, but they are also relatively cheaper to develop and manufacture than oral liquids or suspensions, par-enterals, or suppositories. Figure 4 shows, quite clearly, that even the elderly primarily make use of solid oral dosage forms [162]. 

Oral (PO = per os) By the mouth. Oral administration is the most common route employed for a variety of dosage forms tablets, capsules, liquids, suspensions. The major site of absorption is the small intestine. Alcohol is absorbed from the stomach. 

The present chapter deals with calculations involving oral liquid dosage forms including homogenous systems such as syrups and elixirs, and heterogenous systems such as suspensions. 

Suspensions are two-phase systems consisting of a finely divided solid dispersed in a liquid, solid, or a gas (Table 6). They are appropriate when the drug to be incorporated is not sufficiently soluble in an ordinary solvent or cosolvent system. They are used orally and topically. Examples of compounded suspensions include pediatric oral liquids where a commercial pediatric dosage form is not available. Commercial tablets and capsules are formulated into a vehicle and can be individually flavored to the patient s preference. 

Excretion - Following oral administration of an 80 mg dose of C-isotretinoin as a liquid suspension, C-activity in blood declined with a half-life of 90 hours. The metabolites of isotretinoin and any conjugates are ultimately excreted in the feces and urine in relatively equal amounts (total of 65% to 83%). After a single 80 mg oral dose of isotretinoin to 74 healthy adult subjects underfed conditions, the mean elimination half-lives of isotretinoin and 4-oxo-isotretinoin were approximately 21 and 24 hours, respectively. After single and multiple doses, the observed accumulation ratios of isotretinoin ranged from 0.9 to 5.43 in patients with cystic acne. 

We have established that codeine is most commonly taken as an oral medication. So, once a pill or liquid suspension containing codeine is swallowed, what happens Figure 3.4 gives a simplified answer. 

Part IC Specific requirements for manufacture of oral liquids (syrups, elixirs, emulsions, and suspensions)... 

In the guide to inspection of oral solutions and suspensions [29], it is stated that in some oral liquids microbiological contamination can present significant health hazard. For instance, microbiological contamination with gram-negative... 

Choosing an acceptable preservative when developing an oral liquid formulation is primarily limited by the number of approved excipients. As Table 10 demonstrates, there are many preservatives listed in the FDA inactive ingredient guide for dosage forms other than oral liquids however not many have been commonly used in oral solutions or suspensions. 

It is essential to understand how and when the polymorphs of drug substance in oral liquid dosage forms and suspensions can be controlled. One approach to study this phenomenon is to seed the formulation with a small amount of a known polymorphic crystal (other than what is used for the product), which is a common practice to rapidly determine what effect this may have on long-term storage. From these types of studies, the appropriate excipients can be used to preserve the specific polymorphic form desired. However, even when the drug in its crystalline form is studied extensively, there are cases when a previously unknown polymorph may be formed in solution and lead to precipitation (14). 

Haloxon is probably the safest of the organophosphate anthelminthics (37). It is approved by the Food and Drug Administration (FDA) for use in sheep, cattle, and goats at a dosage of 30-50 mg/kg bw. It is not intended for use in swine and poultry, although certain parasites can be very effectively controlled by the drug in these hosts. It is usually administered orally in the form of a paste, bolus, drench, or liquid suspension, and as a feed premix for poultry. 

Liquids and semisolids. Include oral liquids, injectable, aqueous, and oil-based liquids, emulsions, suspensions, dispersions, solutions, drops, lotions, creams, ointments, pastes, gels, liniments, aerosols and foams, suppositories, and pessaries. 

The oral route of drug administration may be indicated for some conditions in pediatric patients, such as in dacryocystitis and orbital or preseptal cellulitis. Young patients are able to swallow liquid suspensions and solutions more easily than oral solids (e.g., tablets or capsules). Oral medications are the most reliable form of dosing and delivery and continue to be the mainstay in pediatric drug therapy. 

This important testing procedure is best performed using either unit of use volume (e.g., 5 mL of oral liquid or a spray actuation of an oral inhalation product) or sampling from a well-mixed dispensing container from the top, middle, and bottom of the suspension. 

Oral dosage forms available for administration to animals include oral solutions, liquids, suspensions, gels, pastes, capsules, tablets, ruminal boluses, powders and granules for addition to feed, soluble powders for... 

Adjustments in pH lo maintain water solubility cun sometimes lead lo chemical stability problems. An example is indomelhacin (HA acid pK ,4.S). which is unstable in alkaline media. Therefore. Ihc preferred oral liquid dosage form is a suspension buffered at pH 4 to 5. Because this is near the drug s pK . only. W f will be in the water-soluble form. There is a medical indication requiring intravenous administration of indomelhacin to premature infants. The intravenous dosage form is the lyophilized (freeze-dried) sodium salt, which is reconstituted just prior lo use. 

Oral liquids would typically be aqueous, nonaqueous, or blends to create a solution. In some cases they may be a suspension if it is difficult to find a vehicle that completely solubilizes the active or yields chemical stability. The liquid may be used directly as is from the container or, if sold in a concentrated form, is diluted before administration. Oral... 

Many of the criteria described for parenteral solutions should be considered for other solution formulations however, the pH values of the solutions are not as critical as for the parenteral route. If it is not possible to achieve the required solubility, oral liquids may simply be formulated as a suspension, though solution forms are preferable to ensure good product homogeneity and patient compliance. 

As described previously, unpleasant tasting drugs for administration as oral liquids are often presented as suspensions of insoluble salts to improve patient acceptability. An example of this is the bitter tasting analgesic drug, propoxyphene, which is presented as the hydrochloride salt in tablets and as the napsylate salt in oral suspension formulations. 

Many of the principles here are the same as for normal oral aqueous suspensions, except that the liquid is essentially non-polar, hence steric stabilisation is thought to be more important than by electrostatic means (DLVO theory). A stabilising agent is normally added to give an adequate suspension. The agent may also act as a valve lubricant, which may be necessary for... 

The oral route is used for tablets, capsules, liquids, suspensions, and elixirs. Don t use this route if the patient cannot swallow or is not conscious or alert. 

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