Ophthalmic dosage form

Ophthalmic Dosage Forms. Ophthalmic preparations can be solutions, eg, eye drops, eyewashes, ointments, or aqueous suspensions (30). They must be sterile and any suspended dmg particles must be of a very fine particle size. Solutions must be particle free and isotonic with tears. Thus, the osmotic pressure must equal that of normal saline (0.9% sodium chloride) solution. Hypotonic solutions are adjusted to be isotonic by addition of calculated amounts of tonicity adjusters, eg, sodium chloride, boric acid, or sodium nitrate. 

The choice of a particular inactive ingredient and its concentration is based not only on physical and chemical compatibility, but also on biocompatibility with the sensitive and delicate ocular tissues. Because of the latter requirement, the use of inactive ingredients is greatly restricted in ophthalmic dosage forms. 

Factors that may increase absorption from ophthalmic dosage forms include lax eyelids of some patients, usually the elderly, which creates a greater reservoir for retention of drops, and hyperemic or diseased eyes. 

Although conventional eye drops still represent about 90% of all marketed ophthalmic dosage forms, there have been significant efforts towards the development of new drug delivery systems. 

Topical administration of the fluoroquinolones to immature animals does not cause arthropathy, and the ophthalmic dosage form does not appear to affect the weight-bearing joints in humans. All the topical ophthalmic fluoroquinolones, except levofloxacin, are approved for use in patients 1 year of age and older. 

Is the drug a dry or liquid oral or ophthalmic dosage form only PP... 

Ocular topical drug delivery is particularly challenging because of the inherent difficulties associated with absorption of topically applied drugs into the eye. Ophthalmic dosage forms are administered via the topical route to treat both surface and intraocular conditions. Consideration of the anatomical and physiological features of the eye, as well as the physicochemical properties of the drug, are all important when developing a topical ophthalmic delivery system. 

The exact product optimisation studies to be conducted will depend on the type of ophthalmic dosage form to be developed (liquid drops, semi-solid gel/ointment or solid device). However, the dosage form type should be clearly defined from the product design evaluation and supporting preformulation studies, to enable the formulator to focus on the most relevant product optimisation studies. 

Table 12.5 Formulation components used in common ophthalmic dosage forms. ...

Aseptic manufacture has diverse applications. It is in use with liquid and solid sterile parenteral and ophthalmic dosage forms in simple and complex presentations including glass ampoules, rubber-sealed glass vials, plastic ampoules, prefilled glass syringes, etc. The form of presentation may be single-dose or it may... 

The most common ophthalmic dosage forms are solutirms. ointments, and su.Hpen sion.s. According to a recent article (I), the.se account for nearly 90 of currently available ophthalmic formulations in the United Slates, and a similar percentage is presumably valid for the global market. The individual shares are 62.4% (solutions), 17.4% (ointments), and 8,7% (suspensions). Solutions, in spite of (heir... 

Each type of ophthalmic dosage form has advantages and drawbacks. The administration of aqueous eye drops appears to be the most practical and comfortable dosage form for an ocular medication. However, the residence time on the eye is very short. Viscous eye drops and eye ointments adhere better to and stay longer on the ocular surface. 

Figure 1. Essential components of an ophthalmic dosage form.

It is hoped that the present review, notwithstanding its incompleteness, will provide some useful information to readers (such as clinicians, toxicologists, etc.) not directly involved in the formulation, development and testing of ophthalmic dosage forms. 

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