Dosage forms specific topics

Concern for the physical and chemical integrity of topical systems is no different than for other dosage forms. However, there are some unique and germane dimensions to stability associated with semisolid systems. A short list of some of the factors to be evaluated for semisolids is given in Table 12. All factors must be acceptable initially (within prescribed specifications), and all must remain so over the stated lifetime for the product (the product s shelf life). 

Very few injectable dosage forms have been specifically developed and approved by FDA for intraocular use. However, the ophthalmologist uses available parenteral dosage forms to deliver antiinfectives, corti-costerioids, and anesthetic products to achieve higher therapeutic concentrations intraocularly than can ordinarily be achieved by topical or systemic administration. These unapproved or off-label uses have developed over time as part of the physician s practice of medicine. However, these drugs are usually administered by subconjunctival or retrobulbar injection and rarely are they injected directly in the eye [301]. 

This part of the chapter is based on consideration of the published EPARs at the EMEA s web site. At the time of writing there were more than 60 EPARs available. The contents of the pharmaceutical assessment section of each of these were examined, and detailed notes were made from more than 50 of those documents. The amount of information in the different EPARs varies considerably. Some have specific sections with the heading development pharmaceutics, while others include relevant information in the text without a heading. In some cases there are simple statements to the effect that satisfactory pharmaceutical development data were submitted. Therefore, an attempt has been made to glean information of a general nature, and this will be presented as a discussion of relevant topics by dosage form. 

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