Safila Naveed*, Sania Basheer and Fatima Qamar
Jinnah University for Women, Pakistan
Received date: November 25, 2016; Accepted date: May 05, 2016; Published date: May 12, 2016
Citation: Naveed S, Basheer S, Qamar F (2016) Stability of a Dosage Form and Forced Degradation Studies. J Bioequiv Availab 8:191-193. doi:10.4172/jbb.1000292
Copyright: © 2016 Naveed S, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
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The stability of the pharmaceutical formulation during its entire shelf life in its final packaging is an important matter. Stability study does not only cover the physiochemical aspects of the drug but also explains the safety and efficacy of the product during its entire shelf life. Force degradation studies are the studies in which stress conditions or accelerated conditions are provided to the drug in bulk or product. For the development of stability indicating methods especially when insufficient information is accessible about degradation products and to obtain information about the degradation pathways and degradations products that might affect during storage conditions forced degradation studies are performed. Forced degradation studies help to facilitate pharmaceutical development, manufacturing, production and packaging where knowledge of chemical behavior can be used to improve drug product. An FDA and ICH regulatory body portrays the layout of these stability limitations for the stability and degradation point of view.
Stability; Force degradation studies; Safety and efficacy; Shelf life; Pharmaceutical formulation
The stability of the pharmaceutical formulation during its entire shelf life in its final packaging is an important matter . Any change in the physical, chemical, micro biological and therapeutic properties in any component of the drug whether it is active or excepient will lead to the un-stability [2-4]. Therefore due to this reason during designing and development of new dosage form special consideration is given that both excipients and active should remain stable and retain their properties during entire their shelf life. And such product must.
• Contain not less than 90% of its therapeutic activity.
• Contain at least 90% of its stated concentration.
• Contain an effective concentration of added preservatives.
• Have no visible change, that is, discoloration, precipitation and development of off odors.
• Contain no toxicity and irritancy.
In United stated Pharmacopeia (USP) definition of stability is given as “the ability of a product to retain its characteristics that it possessed during its manufacturing (physical, chemical, micro biological, therapeutic properties) within specified limits throughout its period of storage and use” .
According to ICH guidelines pharmaceutical stability testing defined as “systematic experiments conducted on pharmaceutical products to understand and provide evidence how the quality of a drug product varies under the influence of variety of environmental factors such as temperature, humidity, and light and to set re-test period for the drug or a shelf life for the drug product and recommend good storage condition” .
Stages of stability studies
Stability studies are conducted at every stages of the drug life cycle from 1st stages of product development to late stage follow up studies. There are 6 different stages:
Stage 1: Early stage i.e., stress and accelerated testing with drug substances.
Stage 2: Stability on pre-formulation lotes/batches.
Stage 3: Stress test done on scale up batches.
Stage 4: Accelerated and long term testing for registration purposes.
Stage 5: Enduring stability testing.
Stage 6: Follow up studies.
Importance of stability studies
The stability study that we done play a significant role in the lifecycle of a successful pharmaceutical formulation and product. Stability study does not only cover the physiochemical aspects of the drug but also explains the safety and efficacy of the product during its entire shelf life [7-11].
Factors influencing drug stability
Moisture: Water soluble solid dosage form will dissolve when comes in contact with any moisture layer and leads to create many physical and chemical changes in the dosage leading it to lose its properties .
Excipients: Some excipients like starch and povidone have high water contents and affect the stability by increasing the water content of the formulation. Sometimes chemical interactions between the excipients and the drug can occur and lead to decrease in stability .
Temperature: Changes in temperature have sometimes drastic effect on the stability of drug. Increase in temperature usually causes increase in hydrolysis rate of drugs. The effect of temperature on stability described by Arrhenius equation .
pH: pH has great effect on the rate of decomposition of drugs that are hydrolyzed in solution. To minimize this effect drug are formulated at the pH of maximum stability using buffers .
Oxygen: The presence of oxygen promotes oxidation in some drugs. Drugs which have higher rate of decomposition when exposed to oxygen are stabilized by replacing the oxygen in the storage container with nitrogen or carbon dioxide [16-17].
Light: Certain drugs are photosensitive and their rate of decomposition enhances when exposed to light. Their susceptibility can be tested by comparing it stability when exposed to light to that when stored in dark. Photosensitive drugs should be stored in amber glass containers and should be kept in dark .
Force degradation studies
Force degradation studies define as the studies in which stress conditions or accelerated conditions are provided to the drug in bulk or product for two reasons i.e., to when developing stability indicating methods specially when very little information is available about degradation products and secondly to get information about the degradation pathways and degradations products that might effect during storage conditions [19-21].
Degradation studies of a drug substance
1. Stressing the drug substance in solution or suspension at alkaline and acidic pH and under oxidation conditions.
2. Stressing the solid bulk drug substance at temperature and temperature + humidity conditions in excess of accelerated conditions.
3. Stressing the drug substance photolytically in the solid state or in solution excess.
4. Demonstration of the specificity of stability indicating methods with forced degraded samples.
5. Full characterization of the degraded products by means of NMR, mass spectrometry(MS), UV analysis
6. Chemical and physical properties of the degradation products, if available.
Conclusion will be discussed in Table 1.
|Drug Substance||Drug Product|
|Conditions||Solid||Solution/Suspension||Solid (Tablet capsules, blends)||Solution
IV, oral suspension
Table 1: General protocol for forced degradation studies (stress studies) of a drug substance and drug product.