Time to expiry

The longer the option s time to expiry, the more valuable is the option. In all cases, the options expiring in May are more valuable than those expiring in April with the same strike price and, similarly, June options are more valuable still. This is sensible when one thinks of the risk experienced by the option seller. The further the expiry date, the greater the uncertainty as to where the price of the underlying bond will be in the future, and therefore the more valuable the right to execute a trade in the future at a price fixed at the outset. 

This demonstrates the point made earlier that an option s premium increases when the time to expiry, the volatility, or the interest rate (or any combination of these) is increased. 

As noted in chapter 8, the value of an option is a function of five factors The price of the underlying asset The option s strike price The options time to expiry... 

The manufacturer should advise on proper storage conditions for both warehouse and shop, and on recommended shelf-life. The criterion to be applied in determining storage conditions and shelf-life is that, at time of sale, no detectable loss of nutritional quality shall have occurred. Date coding shall be observed and customers attention shall be drawn to expiry dates for perishable commodities. Adequate control of stock rotation must be practised in both warehouse storage and retail outlets to ensure that the commodity meets these requirements. 

The current value (fair price) V of the option should depend upon the current asset price S and the time remaining to expiry, T — t. The Black-Scholes equation (derived in Chapter 7) states that V(S, t) satisfies... 

Epinephrine is an inherently unstable chemical in aqueous solution, even at a low pH and in the presence of an antioxidant such as sodium metabisulfite, up to 1 mg/ ml. With the passage of time, the epinephrine dose gradually decreases due to degradation into inactive compounds. If the expiry date has passed, the epinephrine dose correlates inversely with the number of months or years past that date, and will likely be lower than the dose stated on the label even if the solution appears clear and colorless. Nevertheless, if this is the only source of epinephrine available for injection, it should be used in preference to not administering epinephrine at all [32]. 

Very strict price control systems can give rise to higher prices at the time of introduction of a new product and the weakening of potential price reductions on expiry of a product s patent (the case for 88 per cent of products in the USA). These observations support the idea that it does not appear to be at all efficient to continue with the system of product-by-product price intervention currently in force in Spain. A regulation system that gives the company flexibility of pricing and excludes products that are subject to competition would be far more recommendable.1... 

All antibodies age and therefore have a specific shelf life. Aging may be different for different antibodies, and real aging may be quite different from the expiry dates printed on containers of antibodies. Mixtures of antibodies as are found in secondary antibody cocktails may show distinct aging differences. In other words, over time, one of the species in a secondary cocktail may age at a more rapid rate than the other(s). This would result in a significant decrease in sensitivity for that particular species of primary antibody. A user performing IHC stain runs with multiple tissues, and using primary antibodies from more than one species, must utilize primary controls for each species of primary antibody to detect a change in one of the components of the secondary antibody cocktail. 

Storing and titrating antibodies correctly are often easy solutions when no staining is observed. Some antibodies are extremely sensitive to repeat freeze-thaw cycles and others have a limited shelf life, as evidenced by a short expiry dates, ft is important to check the compatibility of the primary and secondary antibodies before starting IHC, as using the wrong secondary IgG is a common but easily corrected problem. As mentioned, antigen retrieval can be a problem when tissue has been overfixed, so special attention should be paid to fixation time and, once optimized, should be held constant for all subsequent runs. 

The dye ingress challenge test is performed at the end of expiry to show container-closure integrity over the production shelf life. Dye ingress testing is performed on vials having rubber stoppers exposed to the maximum exposure time and temperature during sterilization cycle. 

Calibration of dissolution equipment. It is very important to ensure that the calibration of the dissolution equipment is kept up to date. The expiry date of the calibration status should be checked each time that dissolution testing is performed. 

Extrapolation of data from one material to another must always be based on sound scientific principles and all available data. Even so, extrapolation always bears risk. To demonstrate that every batch of clinical trial material was within applicable specifications for the duration of its use in clinical studies, some firms test every batch of clinical trial material at expiry. This is especially valuable when an expiration-dating period was not based on real-time data for the precise clinical trial material in the precise container-closure used in the clinical trials. 

By the time of the development of the CWC RevCon provisions in the late 1980s, the convening of Review Conferences of other multilateral arms control treaties at approximately five-yearly intervals had become an estabhshed norm, in particular for the 1968 Nuclear Non-Proliferation Treaty (NPT) and the BWC. The CWC negotiators readily agreed that CWC RevCons should be held no later than one year after the expiry of the fifth and the tenth year after entry into force of this Convention . Although the actual procedures to initiate RevCons under the CWC dif-... 

When determining an expiry date, the analyst should take into account the frequency of use of the standard. The number of times the bottle is opened or aliquots removed and the temperature at which it is stored will have an impact on the integrity of the standard. Once the integrity of the standard has been significantly altered then the standard has to be disposed of and a new standard made. 

IPC-generated data and records subject to regulation by 21 CFR Part 11 are required to be retained for a defined retention period, typically for a number of years beyond the expiry date of the product. The retention period is to be determined by reference to predicate rules and a risk-based assessment of the value of the record over time. 

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