PHARMA - Nature, Sources, and Drug Dosage Forms

Drugs

Medicines or other substances which have physiological effects when ingested or, otherwise, when introduced into the body.

Drugs

May also be substances which may cause dependencies due to their behavioral or mood-altering actions.

Cure disease, Relieve unwanted symptoms, Ease pain, Correct deficiencies

What are the effects of drugs?

Chemical properties, Biological activity, Medical purpose

What are the characteristics of drugs?

Pharmacokinetics

What the body does to the drug once it is inside the body. e.g. Absorption, Distribution, Metabolism, Excretion

Pharmacodynamics

What the drug does to the body. e.g. Mechanisms of action, Effects (side effects or adverse effects)

Pharmacognosy

Stems from herbalism. Science which identifies and distinguishes drugs sourced from plants to those which are derived from animals or animal products.

Pharmacobiotechnology

In the modern day context, many drugs are synthesized from their original source in the laboratory through their very thorough chemical process or even genetic engineering

Tincturing

Extraction of the raw ingredient which are useful for the purpose of the study or research

Elaboration

Process of standardization and validation of drugs

Testing

Step after tincturing or elaboration. Must be emphasized that a good part of drug development is testing for safety, effectivity, and efficacy

Approval

Prior to approval, the risks from the effect of the administered drug is weighed against the benefits gained from the use of that drug. Once deemed safe it can then be approved

Marketing

Brand or trade name

Chemical name

Drugs should be identified and classified according to?

Generic term, Brans name, Chemical name

How do you classify drugs according to specific names?

Chemical similarity, Use, Biological effect

How do you classify drugs according to general terms?

Over-the-counter (OTC), Prescription

How do you classify drugs according to legal?

Agonist-Receptor Interaction

Most medicines exert their effect by making physical contact with receptors on cell surface. “A key fitting into a lock”. RECEPTORS located anywhere in the body play a critical role on knowing or producing the effect of a drug or substance which occupies it

Agonists

Open cellular locks and are often the first step of communication between the outside of a cell and its internal milieu

Antagonist

Drugs that act to COMPETE with natural agonists but act as DECOYS, freezing up the receptors and PREVENTING agonists from using or occupying it

Molecular Shape

The key for Agonists to “fit” into their respective receptors. After “fitting” into receptors, agonists effect their actions depending on the kind of cell or tissues that they belong. Side effects may be significant especially when the agonist encounters receptors other than the target receptors

Drug Resistance

A cell’s defense mechanism against the onslaught of substances that it deems foreign

Multi-Drug Resistance

Caused by Multi-drug Resistance pumps (MDRs)

Multi-Drug Resistance Pumps (MDRs)

In humans, can frustrate efforts to get a drug where they need to go. Virtually all living things has this.

Plants

Have evolved to produce natural chemicals that block the action of bacterial MDR pumps

Periwinkle (Chichirica)

What is the plant source of Vincristine, an anticancer drug?

Willow tree bark

What is the plant source of Aspirin?

Chinchona bark

What is the plant source of Quinine?

Pacific Yew Tree

What is the plant source of Taxol?

Guggul Tree

What is the plant source of Guggulsterone?

Poppy plant

What is the plant source of Opium and Heroin?

Meadow saffron

What is the plant source of Colchicine?

Atropa belladonna

What is the plant source of Atropine?

Papaver somniferum

What is the plant source of Morphine?

Cannabis

What is the plant source of Marijuana?

Snakes (Reptiles)

What is the animal source of Anti-venoms?

Horses

What is the animal source of Equine vaccines?

Pigs (Bovine)

What is the animal source of Hormones (i.e. insulin)?

Duck Embryo

What is the animal source of Rabies vaccines?

Cytosar-U

Derived from sea sponge. Staple for treating leukemia and lymphoma

Ecteinascidin

Derived from sea tunicate from the reefs of the West Indies (Ecteinascidia turbinate). For treatment of liposarcomas and leiomyosarcomas

Prialt

Drug discovered by Dr. Baldomero Oliva (University of Utah, Salt Lake City). Derived from a cone-snail found in the waters of the Philippines. Jams nerve transmission in the spinal cord and blocks certain pain signals from reaching the brain. This effect is produced by substances called Conotoxins

Bacteria

Have an uncanny ability to protect or defend themselves against antibiotics by having Multidrug Resistance Pumps (MDRs)

Multi-drug Resistance Pumps (MDRs)

Large ejection system pumps that traverse the cellular membranes

Streptomyces griseus

What is the bacterial source of Streptomycin?

Penicillium notatum

What is the bacterial source of Penicillin?

Semi-Synthetic Drugs

Derived from natural sources/compounds, but are chemically modified in the laboratory. To enhance activity or reduce toxicity/adverse effects in every modified generation of the drug

Synthetic Drugs

Created in the laboratory using chemical processes

Genetically Engineered Drugs

Ex: recombinant DNA technology insulin, vaccines, monoclonal antibodies

Endogenous Sources

Neurotransmitters, hormones that naturally occur in the body. Ex: oxytocin, dopamine, epinephrine

Minerals

Common examples: Iron, Lithium, Gold, Magnesium sulfate

Chemists

Have an essential role in extracting the lead raw ingredient from the source (plant and marine natural products) with a known potential found in minute quantities into useful medicines

Combinational genetics

Are used to custom-make products that do not even exist in nature. Genetic instructions are removed for entire metabolic pathways from certain microorganisms. These instructions are altered then put back in, generating new and different “NATURAL” products

Drug Dosage Forms

Physical form of a dose of a chemical compound used as a drug in medication intended for administration or consumption

Tablets

The most administered or ingested is in the tablet form. Compressed solid drugs

Compressed

A characteristic of tablet that is single, multiple

Coated

A characteristic of tablet that is sugar-, film, -enteric

Route

A characteristic of tablet that is either sublingual or bucca

Scored

A type of tablet scored in the middle for easy division in half

Chewable

Tablets meant to be chewed, NOT swallowed (e.g. Antacid)

Effervescent

Tablets dissolved in water before ingestion, releasing gas (e.g. Vitamin C)

Sustained-release

Tablets designed to release active drug component at various times or durations along the GIT

Oral Disintegrating Tablets

Tablets that disintegrates in the mouth quickly (e.g. Ondansetron ODT)

Active drug component

25% of the tablet’s structure

Filler

65% of the tablet’s structure. To increase the bulk in order to produce a tablet of practical compression

Binders

To impart cohesive properties to the powders by formation of granules

Lubricants

To reduce interparticulate friction. To prevent adhesion of powder to surfaces of patches and dyes. To facilitate tablet ejection from the dye

Disintegrants

To facilitate rapid break-up and disintegration after administration

Surfactants

To aid in wetting and dissolution of drugs

Initial Wetting

A step in drug administration of tablets: The tablet surface wets and methocel polymer begins to hydrate, forming a gel layer. Initial burst of drug from the external tablet layer also occurs

Expansion of Gel Layer

A step in drug administration of tablets: Water permeates into the tablet, increasing thickness of the gel layer. Soluble drugs diffuse through this gel layer

Tablet Erosion

A step in drug administration of tablets: Outer layer becomes fully hydrated, eventually dissolving into the gastric fluids. Water begins to permeate towards the tablet core. If the active drug is SOLUBLE: released primarily by diffusion through the gel layer. If the active drug is INSOLUBLE: released primarily by tablet erosion

Capsules

Round or oblong-shaped gelatin containers filled with medication. Easier to swallow due to their shape and become slippery when taken with water due to their gelatin exterior

Sustained-release

Release of a drug substance from a dosage form or a delivery system over an extended period of time. Provides longer duration of action

Controlled Release

Rate of the drug’s release is more precisely controlled. Avoids very high concentrations in the GIT

Repeat-action capsules

Sequentially releases two full doses of a drug

Hard Gelatin, Soft Gelatin, Spansules

What are the types of capsules?

Spansules

Designed to release drugs at a steady rate over a period of hours. Form of sustained-release capsule

Powders

Finely divided drugs for dissolution or suspension (e.g. Oral rehydration)

Granules

Larger than powders, may be coated (e.g. Omeprazole)

Effervescent (Carbon tablets)

Designed to dissolve in water and release carbon dioxide. Packaged and sold as effervescent powders or may be granulate and sold as effervescent granules

Suppository and Pessaries

Solid medications in a roughly, conical or cylindrical shape. Designed to be inserted into the rectum or vaginal canal to dissolve in the mucosa

Lozenges (Troches)

Dissolves slowly in the mouth for local action. Example: Zinc

Ointments

Simple mixtures of drug substances in an ointment or oily base. Greasy preparations with a petroleum jelly base

Creams

Semi-solid emulsions. Generally less viscid and lighter than ointments. Greater aesthetic appeal due to their non-greasy character and ability to vanish into the skin upon rubbing. Do not offer much protection as ointments. More appealing to patients. Less greasy. Absorbed by the skin

Lotions

Suspensions of solid materials in an aqueous vehicle. Certain emulsions and some true solutions have been designated as lotions due to appearance or application. Non-greasy character

Poultice

Soft, moist, mass of material, typically of plant material or flower, applied to the body to relieve soreness and inflammation. Kept in place with a cloth

Plaster

Adhesive strips of material for covering cuts and wounds

Paste

Contain more solid materials than ointments. Stiffer and less penetrating. Employed for protective function and ability to absorb serous discharges from skin lesions

Aqueous Solutions

Preparations in which the solid ingredients of medications are dissolved completely in a liquid (usually water). Homogeneous and may have color, but is usually clear. Ex: D50-50, oral rehydration

Syrups

Concentrated solutions of/a viscous mixture of sugar in water with a drug or active ingredients. This may contain alcohol or may be flavored. Ex: cough syrups

Mucilage

Jelly-like, viscous substance made out of polysaccharides produced by plants or microorganisms. Expands with water (Has low viscosity). Insoluble in alcohol = gel-like. Characteristics: Often from plants like aloe, gum Arabic, psyllium, linseed. Thick, sticky, slippery if mixed with water. Solubility - expands in water to form a colloidal dispersion. Can degrade or ferment so preservatives may be added

Infusion

Crushed or powdered plant parts are STEEPED in water. The usual solvent is water (typically hot, but may be cold). Strained to separate the plant material from the liquid. Plant parts used: flowers, leaves, soft stems. Suitable for heat-sensitive plant parts where the constituents are destroyed by boiling. Usually lighter color than decoction

Decoction

Drug preparation made by BOILING the crude drug in water for a specific time, cooled, and strained for the extract. Usually done to extract the drug from the hard parts of the plants (e.g. bark, stem). Must be used immediately or stored for a short time (easily spoils)

Aromatic Waters

Saturated solutions of volatile oils in water. Ex: rose water

Aqueous Suspension

Preparations in which the solid ingredients of medications are suspended in the liquid (usually water). The medicine is not dissolved within the liquid. Medications are meant to be shaken well before administering for ingestion

Emulsions

2 immiscible liquids (ex: oil in water) stabilized by an emulsifying agent like castor oil. Distinct from a suspension

Elixirs

Sweetened hydro-alcoholic liquids for oral use. Clear and sweetened solution. Alcohol and water are used as solvents when the drug will not dissolve in water alone. In addition to active drugs, they usually contain flavoring and coloring agents to improve patient acceptance

Essences (Spirits)

Thin watery solutions packed with vitamins and moisturizing agents. Volatile substance of alcoholic or hydro-alcoholic solutions

Tinctures

Alcoholic extracts from plants or animals. Concentrated herbal extracts made by soaking the bark, berries, leaves, or roots of one or more plants in alcohol or vinegar. The alcohol or vinegar pulls out the active ingredients in the plant parts concentrating them in the liquid