Pharmaceutical aids & Flavoring agents

 PHARMACEUTICAL AIDS

The substances which are of little or no therapeutic value, but are essentially used in manufacturing or compounding of various pharmaceuticals are known as Pharmaceutical Aids or Pharmaceutical Necessities.

Classification of Pharmaceutical Aids :-

• Acidifiers and Alkalisers
• Buffers
• Antioxidants
• Hydrocolloids
• Surfactants
• Perservatives
• Filter Aid
• Coloring Agents
• Flavoring Agents
• Sweetening Agents
• Disintegrating Agents
• Lubricants

ACIDIFIERS AND ALKALISERS

Acidifiers :-

Acidifiers are inorganic chemicals that, put into a human (or other mammalian) body, either produce or  become acid. These chemicals increase the level of gastric acid in the stomach when ingested, thus decreasing the stomach pH. 

Out of many types of acidifiers, the main four are:

1. Gastric acidifiers, these are the drugs which are used to restore temporarily the acidity of stomach in patient suffering from hypochlorhydria.
2. Urinary acidifiers, used to control pH in urine.
3. Systemic acidifiers, used to control pH in the overall body.
4. Acids, mostly used in laboratory experiments.

Alkalisers :-

Patients who suffer from achlorhydria have deficient secretion of hydrochloric acid in their stomach. In such cases, acidifiers may provide sufficient acidity for proper digestion of food. Systemic acidifiers, usually given by injection, act by reducing the alkali reserve in the body, and are also useful in reducing metabolic alkalosis. Alkalinizing agents are drugs used to manage disorders associated with low pH. For example, they may be used to treat acidosis due to kidney failure. Used for oral or parenteral therapy, sodium bicarbonate is the commonly preferred alkalinizing agent. Others include potassium citrate, calcium carbonate, sodium lactate and calcium acetate.

BUFFERS

Buffers are acidic or alkaline agents added in formulations to adjust it's pH.

There are two types of buffers.

• Acidic buffers = acetate buffer, hydrochloric acid buffer.
• Alkaline buffers = phosphate buffer.

ANTIOXIDANTS

Antioxidants are compounds that inhibit oxidation (usually occurring as autoxidation), a chemical reaction that can produce free radicals. Autoxidation leads to degradation of organic compounds, including living matter. Antioxidants are frequently added to industrial products, such as polymers, fuels, and lubricants, to extend their usable lifetimes. Foods are also treated with antioxidants to forestall spoilage, in particular the rancidification of oils and fats. In cells, antioxidants such as glutathione, mycothiol, or bacillithiol, and enzyme systems like superoxide dismutase, can prevent damage from oxidative stress.

Known dietary antioxidants are vitamins A, C, and E, but the term antioxidant has also been applied to numerous other dietary compounds that only have antioxidant properties in vitro, with little evidence for antioxidant properties in vivo. Dietary supplements marketed as antioxidants have not been shown to maintain health or prevent disease in humans.

HYDROCOLLOIDS 

A hydrocolloid is defined as a high molecular weight polysaccharide gum that forms a glue-like suspension in water, allowing it to create viscous solutions or gels in aqueous environments. In oral drug delivery, hydrocolloids are used to slow and extend drug release over time.

PRESERVATIVES 

A preservative is a substance or a chemical that is added to products such as food products, beverages, pharmaceutical drugs, paints, biological samples, cosmetics, wood, and many other products to prevent decomposition by microbial growth or by undesirable chemical changes. In general, preservation is implemented in two modes, chemical and physical. Chemical preservation entails adding chemical compounds to the product. Physical preservation entails processes such as refrigeration or drying. Preservative food additives reduce the risk of foodborne infections, decrease microbial spoilage, and preserve fresh attributes and nutritional quality. Some physical techniques for food preservation include dehydration, UV-C radiation, freeze-drying, and refrigeration. Chemical preservation and physical preservation techniques are sometimes combined.

SURFACTANTS

Surfactants are chemical compounds that decrease the surface tension or interfacial tension between two liquids, a liquid and a gas, or a liquid and a solid. The word "surfactant" is a blend of surface-active agent, coined in 1950. As they consist of a water-repellent and a water-attracting part, they enable water and oil to mix; they can form foam and facilitate the detachment of dirt.

Surfactants are among the most widespread and commercially important chemicals. Private households as well as many industries use them in large quantities as detergents and cleaning agents, but also for example as emulsifiers, wetting agents, foaming agents, antistatic additives, or dispersants.

FILTER AID

Filter aids can improve the permeability and sometimes porosity of a filter cake, improve filtrate clarity and help to prevent filter medium blinding. They comprise relatively porous particles such as diatomite, perlite and activated carbon and are either filtered as a precoat onto the medium or mixed as body feed with the suspension during a pretreatment stage; the latter beneficially improves the porosity of a subsequently formed filter cake. Both the cost of filter aid and the need to remove filter aid from the processed solids can present problems; however, the use of filter aids on rotary drum filters and in the filtration of dilute feeds (such as those found in the brewing industries) can bring undoubted benefits.

COLORING AGENT

A coloring agent is any dye, pigment or substance which when added or applied to a food drug or cosmetic is capable of imparting color. Coloring agent is nontoxic and have no side effect on human body. It should be pure, free from all types of impurities. It should have high Tinctorial (coloring) powder in small quantities. It should be stable on storage, It should remain unaffected by light, temperature, moisture, air, oxygen, etc. It should be stable at different pH. It compatible with other ingredients in formulation. It should be soluble in solvent.

FLAVORING AGENT 

The flavor ia the combination of taste and odour, It is the sensory impression of a food or other substances.

1) Natural Flavoring Agent :-

     Flavoring substances obtained form plant or animal origin.

     Ex. aldehyde (vanillin), Aloevera, Mentha/ Peppermint oil, Ginger oil, Lemongrass oil.

2) Nature-identical Flavoring Agent :-

     This flavoring substances obtained or generated by chemical synthesis. These are chemically                    equivalent to natural flavoring agents.

      Ex. Vanillin.

3)  Artificial Flavoring Agents :- 

     These flavoring substances are not present in a natural products. These flovaring substances                   produced by chemical reactions.

     Ex. Cinnamaldehyde and benzaldehyde.

SWEETENING AGENTS

Sweetening agents are excipients after added to pharmaceutical dosage forms to madk bitter taste of drugs. They should be effective im small concentration. They must be stable at a wide range of temperature. Prolonged use of these agents should not produce any harmful effects. They should have very low or non-calorific value. They should compatible with other ingredients in formulations. They should not show batch to batch variations. They should be readily available and imexpensive. 

DISINTEGRATING AGENTS

Disintegrating agent (disintegrant) is an important component of tablet dosage forms. They are added to a tablet formulation to break apart (disintegrate) the compressed tablet when placed in aqueous environments. Disintegration of conventional compressed tablets must occur within 15 minutes.

LUBRICANTS

A lubricant is a substance that helps to reduce friction between surfaces in mutual contact, which ultimately reduces the heat generated when the surfaces move. It may also have the function of transmitting forces, transporting foreign particles, or heating or cooling the surfaces. The property of reducing friction is known as lubricity.

In addition to industrial applications, lubricants are used for many other purposes. Other uses include cooking (oils and fats use in frying pans and baking to prevent food sticking), to reduce rusting and friction in machinery, through the use of motor oil and grease, bio-applications on humans (e.g., lubricants for artificial joints), ultrasound examination, medical examination. It is mainly used to reduce friction and contribute to a better, more efficient functioning of a mechanism.