Ophthalmic products/drugs sterility

Ophthalmic products have to be manufactured sterile and be free from micro-organisms. Once opened, the sterility of a multidose product must be maintained during its period of use. This is usually required for at least 4 weeks, after which the product is discarded. If the drug itself does not possess antimicrobial properties, then an antimicrobial preservative must be included in the formulation to ensure that any micro-organisms accidentally introduced during use are destroyed. 

It is quite rare that the composition or the packaging of an ophthalmic pharmaceutical will lend itself to terminal sterilization, the simplest form of manufacture of sterile products. Only a few ophthalmic drugs formulated in simple aqueous vehicles are stable to normal autoclaving temperatures and times (121°C for 20-30 min). Such heat-resistant drugs may be packaged in glass or other heat-de-formation-resistant packaging and thus can be sterilized in this manner. The convenience of plastic... 

Although ophthalmic drug products can be considered topical products, they have been grouped here with inject-ables because they are required to be sterile (21 CFR 200.50(a)(2)) and the descriptive, suitability, and quality control information is typically the same as that for an injectable drug product. Because ophthalmic drug products are applied to the eye, compatibility and safety should also address the container closure system s potential to form substances which irritate the eye or introduce particulate matter into the product (see USP <771> Ophthalmic Ointments). 

Although ophthalmic drug products can be considered topical products, they have been grouped here with injectables because they are required to be sterile and the descriptive, suitability, and quality control information is typically the same as that for an injectable drug product. 

Topical dosage forms such as unpressurized sprays, lotions, ointments, solutions, and suspensions may be considered for marketing in glass bottles with appropriate dispenser. Some topical drug products, especially ophthalmic, are sterile or may be subject to microbial limits. In these cases, packaging material and handling should be done as those for injectables. 

According to Davies [174], topical ophthalmic suspensions have a number of limitations compared to solutions. They need to be adequately shaken before use to ensure correct dosing, a process which can result in poor patient compliance. In addition, they need to be sterilized, which may cause physical instability of the formulation. Furthermore, the amount of drug required to achieve only a moderate increase in bioavailability is very high, rendering suspensions expensive in terms of their production costs [175],... 

It is noteworthy that, at least presently, sterilization is not required for all drugs. It depends on the type of administration. Hence, it concerns mostly ophthalmic preparations, sterile topical products and injectable solutions, including intramuscular, intravenous and sub-cutaneous ways. 

The primary focus here will be in S3mthesized pharmachemical that would go into two types of pharmaceutical products parental drugs, such as antibiotics or ophthalmic where regulatory authorities require sterile products for topical treatments involving the eye. 

A new field of radiation application is the radiation sterilization of drugs. The requirement for sterility of drugs depends on type of administration. It concerns mostly ophthalmic preparations, sterile topical products, and injectable solutions. In some cases, radiation sterilization appears to be an attractive alternative to other types of sterilization, e.g., heat sterilization. For drugs the usual requirement (six orders of magnitude decrease in the microorganism level) is achieved by applying an absorbed dose of 25 kGy. 

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