@jauhar123 | Posted 12 Jun. 2019
There are two main types of formulations that are used by pharmaceutical companies in Durham NC while developing medicinal drugs. Further, the form of the drug varies by its route of administration, say, like tablets, pills, capsules, and so on. The three main types of formulations are enteral formulation, parenteral formulations, and topical formulations.
***** drugs are usually taken in the form of tablets or capsules. The drug, active substance, itself should be soluble in aqueous solution at a controlled rate. Factors such as particle size and crystal form can considerably affect dissolution. Fast dissolution may not always be ideal. For example, slow dissolution rates can extend the duration of action or avoid high initial plasma levels. Treatment of active ingredient by special ways like spherical crystallization can have some benefits for drug formulation.
A tablet is typically a compressed preparation that contains:
5 to 10% of the drug (active substance),
80% of fillers, disintegrants, glidants, lubricants, and binders; and
10% of compounds which ensure easy disaggregation, disintegration, and dissolution of the tablet in the stomach or the intestine.
The dissolution time can be altered for a rapid effect or sustained release.
Special coatings on the tablet can make it resistant to the acids present in the stomach such that it only disintegrates in the jejunum, duodenum, and colon due to the enzyme action or alkaline pH.
Pills may be coated with sugar, varnish, or wax to cover the taste.
A capsule is a gelatinous cover enclosing the active substance. These can be designed to remain intact for a few hours after ingestion so that the absorption gets delayed. They can also contain a mixture of slow and fast release particles in order to produce rapid as well as sustained absorption in the same dose.
These types of formulations are also called injectable formulations and are used with intravenous, intramuscular, subcutaneous, and intra-articular administration. The drug is generally stored in liquid, and if unstable, in lyophilized form.
Most parenteral formulations are unstable at higher temperatures and require storage at refrigerated or sometimes, in frozen conditions. A cold chain is the logistics process of delivering these drugs to the patient.
Many of the protein formulations are parenteral due to the fragile nature of the molecule which will be destroyed by enteric administration. Proteins have tertiary and quaternary structures that can be degraded or cause aggregation at room temperature. This can impact the safety and efficiency of medicine.
Liquid drugs are stored in vials, ampoules, IV bags, cartridges, and prefilled syringes. Many compounds are added in them such as solubilizers, stabilizers, buffers, bulking agents, tonicity modifiers, chelating agents, viscosity enhancers/reducers, surfactants, and adjuvants.
Lyophilized drugs are stored in vials, dual chamber syringes, cartridges, and prefilled mixing systems.
Medicinal drugs developed through topical formulation development are very common and can be used to treat various conditions along with skin conditions. The main forms in which topical formulation drugs are available are as follows.
Cream: It is an emulsion of oil and water in almost equal proportions. They are mainly applied to the outer layers of skin.
Paste: It takes a combination of three agents to form a paste, and they are oil, water, and powder. It is mainly an ointment in which a powder is suspended.
Ointment: Combines oil, say, about 80% and 20% of water. They are an effective barrier against moisture loss.
Gel: This medicine liquefies when it comes in contact with the skin.
Powder: A finely subdivided solid substance that is applied onto the affected areas of the skin.