The Sampling Plan

Sampling is always done for a specific purpose and (his purpose will determine, to some extent, the sampling procedure used. Canned food is examined for 

A sampling plan needs to be established which describes when, where and how samples are to be taken. IUPAC [1] define the sampling plan as follows  

A predetermined procedure for the selection, withdrawal, preservation, transportation and preparation of the portions to be removed from a population as 

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Because the sampling plan is central to the overall objective of an LSMBS, the plan should be statistically designed. The overall intent of the design is that... 

Once the target number of samples was defined, the frequency of collection and the number of samples to be collected on each collection date were determined, based on an overall total sampling period of 1 year. The sampling plan specified collection every other week, primarily to accommodate the workload at the analytical laboratories. Sampling had to occur early in the week to preclude problems with shipping samples over the weekend. With these considerations in place, specific dates for collection of commodity samples could readily be set. 

The sampling plan for the OPMBS required that no organic or hydroponically grown produce be obtained, that the precise commodity, i.e., head, not leaf lettuce, be collected, and that only two representative single-serving samples of each commodity be collected on a given date by each of 20 shoppers. The plan also specified two back-up (secondary) stores for each primary store and instructed that the collection coordinator be notified if samples could not be collected on the specified date so that the sample collection could be rescheduled. 

The implications of the analysis have to be considered before taking the sample or devising a sampling scheme. It is the responsibility of the analytical chemist, through discussion with the customer, to establish the real nature of the problem. How much cadmium is there in this sample is not sufficiently specific. You must always ask why the information is required. The answer affects both the sampling plan and the choice of analytical method. These will depend on the acceptable level of uncertainty in the final result. 

Systematic sampling is one of the most commonly used sampling techniques. This type of sampling involves taking increments from the bulk material at predetermined intervals, as defined by the sampling plan. 

The sampling plan should specify the number and size of primary samples which need to be obtained from the lot/batch. It should also describe how the laboratory sample is to be obtained. These issues may well be outside of the analyst s control, but it is important to consider how the validity of any analysis will be affected. 

Most chemical tests are destructive and so all the material cannot be tested. In any case, this would not be very cost-effective. There may be a problem in taking a representative sample from bulk material known to be heterogeneous. The sampling plan must be such that the degree of homogeneity can be tested. 

Random sample inspection from the accepted vials (good) per the sampling plan and disposition (OK for packaging/reinspection)... 

Sampling plan. To determine the number of samples, the areas are reviewed for criticality. Samples are taken from representative location at frequencies specihed in the respective procedures. The sampling frequencies are based on the environmental classihcations per current USP. The sampling plans shall be dynamic with monitoring frequencies and sample plan locations adjusted based on trending performance. It is appropriate to increase or decrease sampling based on this performance. 

Collect a representative sample per the single sampling plan (general level B) and inspect. Record the observation in the attached format. Following is the sampling plan. 

Preliminary Testing Data Any data generated during the developmental and clinical trial phases of the drug may be useful to determine the expected manufacturing process variability. The process variability is an important factor to define the sampling plan to be used in the stability study. 

There should be a sampling plan for finished excipient testing. The sampling plan should be in accordance with the in-process sampling requirements outlined above. It is important that if only one sample from the finished batch is taken, that it be representative of the excipient. This is usually not possible if the lot is not homogeneous. In that event, it is important to establish a sampling plan that assures sufficient samples are taken so that with all samples in conformance, the entire excipient batch is known to be conforming. 

The facilities where the samples are to be taken should be safe with proper access, ventilation, light, etc. Also, fine powders can explode and precautions must be taken to prevent this. All safety concerns should be explicitly mentioned in the sampling plans. 

Validation Sampling Plan. Any process undergoing validation must be sampled. This section will tell the reader the logic that went into the sample plan, the frequency of collecting the samples, the sampling locations, and so on. 

Confidence intervals can be generated for any population parameter. Specifically, a two-sided confidence interval about the mean is an interval that contains the true unknown mean with a specified degree of confidence, 100(1 - a)%. The form of this equation, which depends on the sampling plan, is as follows. For sampling plan 1... 

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