THE SYSTEM OF MEASUREMENT & COMMON LATIN ABBREVIATIONS
USED IN DISPENSING PHARMACY
o The Imperial System of Measurement
• The Avoirdupois System
• The Apothecary System
• The Troy System
o The Metric System of Measurement
The Imperial System of Measurement
The Avoirdupois System
• The avoirdupois system is a system of weights based on a pound of sixteen ounces. It is the everyday system of weight used in the United States, and is still widely used to varying degrees by many people in Canada, the United Kingdom, and some other former British colonies despite the official adoption of the metric system.
• The word avoirdupois is from Old French aveir de peis (later avoir de pois), literally "goods of weight”
• In the avoirdupois system, all units are multiples or fractions of the pound, which is now defined as 0.45359237 kg in most of the English-speaking world since 1959
• The Avoirdupois Units in their original French forms:
• Note: The plural of quintal is quintaux.
• The British adaptation of Avoirdupois Units:
• The American Customary System – Adapted from British System by colonizers in North America
The Apothecaries' system
• Apothecary - A health professional trained in the art of preparing and dispensing drugs; a chemist or a pharmacist
• The apothecaries' system of weights is a historical system of mass units that was used by physicians and apothecaries for medical prescriptions, and also sometimes by scientists.
• The English version of the system is closely related with the English troy system of weights, the pound and grain being exactly the same in both.
• It divides a pound into 12 ounces, an ounce into 8 drachms, and a drachm into 3 scruples or 60 grains.
• Troy weight is a system of units of weight customarily used for precious metals, gun powder, and gemstones.
• Named after ‘Troyes’, France, the troy system of weights was known to exist in medieval times, at the celebrated fair at Troyes in North Eastern France.
• One cubic inch of distilled water, at 62 °F (17 °C), and at a barometric pressure of 30 inches of mercury, was determined to weigh 252.458 troy grains (gr).
• There are 12 troy ounces per troy pound, rather than 16 avoirdupois ounces (oz) in the avoirdupois pound (lb) as in the more common avoirdupois system.
Etymology of some units from imperial system
• Grain: A grain was said equal to the mass of an average grain of wheat taken from the middle of an ear. There are 7,000 grains in the avoirdupois pound and 5,760 grains in the troy pound.
• Scruple: From the Latin word ‘scrupus’, meaning, a small rough pebble or a chip of stone — basically, something small. A scruple is 20 grains.
• Pennyweight: At one time English pennies weighed 24 grains.
• Dram: A fraction of an ounce (an eigth or a sixteenth depending on the system). The word is derived from the ancient Greek coin the drachma . One drachma weighed about one dram.
• Ounce: The word ounce has the same origin as the word inch — the Old English word for one twelfth: uncia. An inch is one-twelfth of a foot and an ounce is one twelfth of a pound.
• Pound: Pound comes from Latin pondus for weight. The abbreviation lb for pound comes from the Roman unit libra (about three-quarters of an English pound), which comes from the Latin libro, to weigh.
• Ton: The origin of this word is the Middle English tun — a big container
• Pint: The word pint came to English from the Spanish word for a mark ‘pinta’ probably a mark that was made on a larger measure (it is 1/3 of a gallon)
• Gallon: The word gallon comes from the Latin ‘galleta’ and refers to a standard container about the same size as a helmet. (The Latin word for helmet is galea.) A gallon is 4 quarts or 8 pints.
The Metric System of Measurement
• This system is used in modern science, includes Meter, Gram. etc.
Latin Terms and Abbreviations
Quantities of Ingredients
• Quantum Sufficiat (or Sufficit) (q.s.) – As much as is sufficient
• Ad – Upto , Sufficient to produce
• Ana (aa) – Of each
• Partes aequales (pt.aeq.) – Equal Parts
• Auristillae (auristill) – Ear Drops
• Capsula (caps.) – A Capsule
• Cataplasma (cataplasm.) – A Poultice
• Cereolus (cereol.) – An Urethral boughie
• Charta (chart.) – A Powder
• Collunarium (collun.) – A nose wash
• Collutorium (collut.) – A mouth wash
• Cremor (crem.) – A Cream
• Emulsio (emul.) – An emulsion
• Enema – An Enema
• Gargarisma (garg.) – A gargle
• Gelatina (gelat.) – A jelly
• Guttae (gtt.) – Drops
• Haustus (ht.) – A draught
• Injectio (inj.) – An injection
• Liquor (liq.) – A solution
• Lotio (lot.) – A lotion
• Mistura (m., mist.) – A mixture
• Naristillae (narist.) – Nasal Drops
• Nebula (neb.) – A spray solution
• Pasta (past.) – A paste
• Pigmentum (pigm.) – A paint (like throat paints)
• Pilula (pil.) – A pill
• Pulvis (pulv.) – A powder
• Tabella or Tabletta (tab.) – A tablet
• Trochiscus (troch.) – A lozenge
• Unguentum (ung.) – An ointment
• Vapor (vap.) – An inhalation
• Vitrella (vitrell.) – A crushable glass capsule
Instructions Relating to Preparation
• Adde, Addatur (add.) – Let (it) be added or simply add
• Calefac, Calefiat (calef.) – Let (it) be warmed or warm it
• Dividatur – be divided
• Dividatur in partes aequales (div. in pt. aeq.) – Divide into equal parts
• Fiat (ft.) – Let (it) be made; make it
• Fiant (ft.) – Let them be made; make them
• Misce. Misceatur (m.) – Mix it
• Misce secundum (m.s.a.) – Mix Pharmaceutically
• Solve – Dissolve
• Infricetur (infric.) – Let (it) be rubbed in
Instructions Relating to Preparation
• Instillandus (instilland.) – To be dropped in
• Miscendus (miscend.) – To be mixed
• Signa (sig.) – Label
• Sugendus (sugend.) – To be sucked
• Sumendus (s. or sum.) – To be taken
• Ut antea (u.a.) – As before
• Utendus (u. or utend.) – To be used
• Ad libitum (ad. Lib.) – As much as you please
• Dimidium (dimid.) – Half
• Dosis (dos.) – A dose
• Guttatim (guttatim) – Drop by drop
• Mensura (mens.) – By measure
• Pro (pro) – For; on behalf of
• Pro dosi – As a dose
• Reliquum (reliq.) – The remainder
Qty. to be sent and manner of sending
• Duplum – Twice the quantity
• In phiala - In a bottle
• Mitte (mitt.) – Send
• Phiala prius agitata (p.p.a) – Shake the bottle first
• Quantitas duplex (qt. dx.) – Twice the qty.
• Talis, Tales, Talia (tal.) - Such
Time of administration/application
• Semel in die. (sem. die) – Once a day
• Bis in die. (b.i.d or b.d.) – Twice a day
• Ter in die. (t.i.d or t.d.) – Thrice a day
• Quarter in die. (q.i.d or q.d.) – Four times a day
• Sexies in die. (sex. in d.) – Six times a day
• Vel – Or
• Bis terve in die (b.t.i.d.) – Two or three times a day
• Ter quaterve die (t.q.d.) – Three or four times a day
• Quotidie (quot.) – Daily
• Vices (vic) – Time
• Ad tres vices (ad 3 vic) – For three times
Parts of the Day
• Prima luce (prim. luc.) – Early in the morning
• Mane (m.) – in the morning
• Omni mane (o.m.) – Every morning
• Jentaculum (jentac.) – breakfast
• Meridie – Noon
• Prandium (prand.) – Dinner
• Vespere (vesp.) – Evening
• Nocte (n.) – Night
• Inter noctem (inter noct.) – During the night
• Hora decubitus (h.d) or Hora somni (h.s.) – At bedtime
• Hac nocte (hac noct.) – To-night
• Cras vespere (cras vesp.) – Tomorrow morning
• Mane sequenti (m.seq.) – The following morning
Correlated time & Other Terms
• Ante cibos. or Ante cibum (a.c.) – Before meals or food
• Post cibos or Post cibum (p.c.) – After meals or food
• Inter cibos or Inter cibum (i.c.) – Between meals or food
• Dolore urgente – When the pain is severe
• Frequenter – Frequently
• Lente – Slowly
• More dicto or Modo dicto (m.d.) – As directed
• Pro re nata (p.r.n) – Ocassionally
• Quoties opus sit (quot.o.s.) – As often as necessary
• Saepe – Often
• Statim (stat.) – Immediately; at once
• Tussi urgente (tuss. Urg) – When cough is troublesome
Typical Prescription from 19th Century
• Until around 1900, medical prescription and most European pharmacopoeias were written in Latin.
• The use of Latin ensured that the recipes could be read by an international audience.
• Cooper and Gunn’s Dispensing for Pharmaceutical Students. Ed, S J Carter