Preservation is a term used to describe the process where something maintains its original form where it can perform a desired function. Product preservation in the pharmaceutical industry is a necessary area in promoting drug shelf life because of the different types of chemicals used in their production, how they degrade and how they are administered. This procedure ensures a product’s optimal pharmacotherapy and patient response to a particular the treatment regime. Spoilage of products can result in detrimental side effects due to toxicity, ineffectiveness of the drug or even loss of life; therefore, preservation methods are vital in eradicating the deterioration of product quality. Magnifying the importance of dispensing of a quality product, factors such as varying temperatures, air, light, relative humidity and microbes have to be accounted for concerning their quality assurance.
The primary determinant of the required preservation method is the active ingredient within the product, how it can undergo a conformational change towards the target site, leading to a decreased interaction and drug delivery to the active site. As a result, Pharmacists have formulated various types of dosage forms, each aimed at achieving adequate bioavailability and therapeutic effect with the least adverse consequences to a patient. Because of the different physical and chemical states, degradation rates and drug delivery presented by each dosage form, the methodology in which they are preserved differs as it has to be complementary to their nature. The most popular method of storage is the highly glorified, “cool dry place” accommodating most tablets, capsules and Polyethylene glycol base suppositories, preventing changes in disintegration, dissolution time, hardness and appearance. Silica gel sachets absorb moisture, disabling the water molecules from increasing the Van der Waals forces and therefore, smoothen the surface micro-irregularities resulting in reduced inter-particle separation. Aluminium foil used in suppository packaging also serves this purpose, will dissolve accordingly when exposed to the 37oC body temperature.
If the not place at cool temperature conditions, oral solutions may lose their flavour and taste, while precipitation with evident discolouration where suspensions may form a caked solid phase and emulsions lose uniformity. Other dosage forms such as Oleaginous and Glycerinated gelatine base suppositories and vaccines are kept refrigerated, maintaining proper cold temperature-controlled supply chain preventing degradation of active ingredients, optimising drug quality until patient reception. Majority of the medication currently found on the market have to be stored in away from light, and liquid dosages are packaged in amber coloured bottles, as there are photosensitive. Solid dosages (tablets and capsules) are kept in white, tight-closed containers, which completely radiate light. On exposure to light, some drugs undergo photodecomposition, resulting in loss of potency and reduced therapeutic activity.
In summative view, product preservation is an important aspect in every manufacturing industry that produces quality products. In pharmaceutical point of view, preservation goes beyond the physical appearance, possible toxic effect posed against a patient. In addition, the mode of storage is also an important part in product preservation because there are considerations of external forces such as temperature, moisture and pressure. These external forces can interfere with the product content causing chemical and physical instabilities.