Pharmaceutics

1.  Definition
 Parts of prescription
 Handling of Prescription
 Errors in prescription

2. Definition
Prescription is any written order for pharmacists to compound and dispense
medicines for patients and this order is written by a qualified doctor, dentist
or any registered medical practitioner.
Praescriptus, which means “before writing” is the Latin phrase gives rise to
the English word “Prescription”

3. Types of Prescription forms
1. Private prescription form:
• This type of prescription is generally written on a form that includes the
prescriber’s name, address, and qualification.
• Rx is written to indicate this is a prescription form.
• This is issued by private prescribers.
2. National Health Service (NHS) prescription form:
• It is only issued for NHS patients i.e. patients suffering from certain
diseases.
• It is issued by Government Prescribers.

4. Parts of prescription
1. Date
2. Patient Information
3. Superscription
4. Inscription
5. Subscription
6. Signa
7. Signature lines, signature, degree
8. Prescriber information
9. DEA (Drug enforcement administration) if required
10. Refills
11.Warnings/label

5. 1. Date
• All prescriptions expire after one year.
• In the case of narcotics and other habit-forming drugs, the date prevents the
misuse of the drugs by the patient.
• It helps a pharmacist to know when the medicine was last dispensed if the
prescription is brought for dispensing.

6. 2. Patient Information
• Name
• Address
• Age
• Weight (optional, but useful – especially in pediatrics)
• Time (used only with inpatient medication orders)

7. 3. Superscription
• Another theory proposed by some scholars is that it drives by the symbol for the god
Jupiter.
• The connection to healing was via prayers that a specific treatment would be effective
and the individual would get better.
• Represented by symbol Rx traditional symbol for a
prescription which is always written before writing a
prescription.
• This is derived from the Latin word ‘recipe’ which means
to take.
• Instruction is given to the pharmacist as well as the
patient to take the medicine as prescribed.

8. 4. Inscription
• This is the main body of prescription which includes the name and dose of
medicine that are prescribed.
• This is written in the English language.
• All medicines are written in separate lines along with the required quantity needed
to treat the disease.
What is the pharmacist to take off the shelf?
• Drug Name
• Dose = Quantity of drug per dose form
• Dose Form =The physical entity needed, i.e. tablet, suspension, capsule
• Example- Paracetamol 500mg ; Paracetamol 650 mg etc.

9. 5. Subscription
• The subscription is the part of the prescription, contain the direction to dispense the dosage
form.
• The number of dosage units and the quantity to be given, written in this part of the
prescription.
• Example:Tab Paracetamol - 10 [ that means 10 numbers paracetamol tablet ]

10. 6. Signa, Signatura orTranscription
• Sig – write, or let it be labeled (Latin terms: Signa or signature)
• Instructions for the patient
• Route of administration - Oral, nasally, rectally, etc
• Take by mouth …, Give, Chew, Swallow whole, etc.
• Number of dosage units per dose -Take one tablet, Give two teaspoonful, etc.
• Frequency of dosing - every six hours, once a day …
• Duration of dosing - for seven days, … until gone,…if needed for pain.
• Purpose of medication - for pain, for asthma, for headache, etc.

11. • VERY IMPORTANT to include purpose as this reduces errors!
“As directed by a physician”
• Special instructions (shake well, refrigerate, etc.)
• Warnings
• Signatura Example: "TDS" means three times a day; "BID" means "bis in die" or
twice a day; "a.c" means before a meal etc.

12. 7. Signature, address, and registration
of Prescriber
• The signature is the part of the prescription, contain the signature of the
medical practitioner, who writes the prescription.
• This makes the prescription a legal document.
• A signature, prescriber registration number is necessary especially in the
case of habit-forming drugs.
• The prescriber must write “brand necessary,” “brand medically necessary,”
or “DAW” (Dispense AsWritten) to get non-generics.

13. 8.Refills or renewal Instruction
• Indicate either no refills or the number of refills you want (do not leave it blank).
• Determines the maximum duration of therapy.

14. Handling of Prescription
• Handling of a prescription means how a prescription is entertained or filled.
• What a pharmacist does with the prescription when a patient comes to the
pharmacy with a prescription.
• Handling of prescription consists of following steps
1. Receiving
2. Reading & Checking
3. Collection &Weighing OfThe Material
4. Compounding
5. Finishing

15. 1.Receiving Of Prescription
• Receiving is the first step of prescription handling and as the name
indicates in this step the prescription is received by the pharmacist.
• One important factor to be remembered in this step is that if a pharmacist
is not available, no other person should receive the prescription.

16. 2. Reading & Checking of Prescription
• The reading of the prescription should be done immediately after its receiving to
estimate the time required for its filling.
• check that all the mentioned materials are available in the pharmacy according to
the prescription.
• If a long time is required for its compounding then inform the patient so that he
may wait or can go and return back at said time.
• The prescription should be read precisely and accurately because my mistake in
reading may result in wrong dispensing and serious harm.
• In case of any confusion consult with the prescriber.
• Before compounding the prescription make sure that all the materials are
available and the required dosage form can easily be prepared in the pharmacy.

17. 3.Collection & Weighing OfThe Material
• The third step of prescription handling is the collection of materials and weighing
them to form a dosage form according to the prescription.
• After carefully reading the prescription, take material containers from shelves or
drawers.
• All the material containers are placed on the dispensing slab on the left-hand side
of theWeighing balance.
• Arrange the materials according to the order of mixing.

18. • Before starting the weighing of materials, ensure that the weighing balance is
calibrated.
• After ensuring calibration status, start weighing materials according to the
prescription.
• After weighing, place the material container to the right side of the balance.
• This method ensures proper and correct weighing.
• The label on material containers should be read carefully three times, one is at the
time when we remove them from shelves, the second is when we take them for
weighing and the third is when we put them back on the shelves after weighing.

19. 4. Compounding Of Prescription
• Compounding means, in this step the pharmacist prepares the dosage forms
according to the prescription.
• For compounding, proper instructions and methods are followed.
• One prescription should be dispensed at a time.
• In recent days, the medicines are supplied in form of dosage forms that are
manufactured by the pharma industries.
• The pharmacist dispenses the correct dosage form mentioned in preparation.
• In the situation where compounding is required in the pharmacy, the exact
calculations and procedures should be followed by the pharmacist.

20. 5.Finishing Of Prescription
• In this step the prescription filling is completed and required medicines are
supplied to patients in suitable containers.
• The containers are properly labelled and the labels should bear the following
information,
• Instructions For Use
• Date of Expiration
• Storage Conditions
• Name of Pharmacy
• Address of Pharmacy
• Prescription Name
• Patient Name
• Registration Number
• Dispensing Date

21. • All the above-mentioned information should be written in clear writing.
• In the case of collapsible tubes which are used for creams and ointments, the label is not
attached in the middle rather it is attached near the top of the tube.
• If the medicine is dispensed in a small container that does not have sufficient space to
attach a label with all required information, attach a serial number to that container and
place it in another large container that has a label with all required information.
• When the prescription is compounded, packed and labelled, it is thoroughly checked to
prevent any errors.
• When all the specifications are according to the prescription, the compounded medicines
are signed and handed over to the patient.

22. Errors in prescription
What are prescription errors?
“Any preventable event that may cause inappropriate medication use or patient
harm while the medication is in control of the health care professional, patient, or
consumer”

23. Errors in prescription
1. Abbreviation:
• In most of the prescriptions, abbreviated terms are used by the prescriber that
leads to major errors during interpretation by the pharmacists.
• For example: ‘SSKI’ is the abbreviated term of ‘Saturated Solution of Potassium
Iodide’.
• It is preferable to avoid these types of misleading abbreviations.

24. 2. Name of the drugs:
• Names of some drugs (especially the brand names) either looks or sounds like.
• So any error in the name of a drug will lead to major danger to the patient.
• e.g. Althrocin – Eltroxin, Acidin – Apidin etc
3. Strength of the preparation:
• Drugs are available in the market in various strengths.
• So a drug must not be dispensed if the strength is not written in the prescription.
• For example, Paracetamol tablet should not be dispensed when no strength is
mentioned in the prescription.

25. 4. Dosage form of the drug prescribed:
• Many drugs are available in more than one dosage form e.g. liquid, tablets,
injections, or suppositories. The dosage form intended for the patient must be
mentioned in the prescription to reduce ambiguity.
5. Dose:
• If an unusually high or low dose is mentioned in the prescription then it must be
consulted with the prescriber.
• Sometimes a sustained-release (SR) dosage form is prescribed thrice or more
times daily.
• Sustained Release dosage forms should be given once or twice a day.

26. 6. Instructions to the patient:
• Sometimes the instruction for a certain preparation is either omitted or
mentioned partially.
• The quantity of the drug to be taken, the frequency and timing of administration,
and the route of administration should be mentioned clearly so that it is easy for
patients to take medicine.

27. 7. Incompatibilities:
• It is essential to check that there are no pharmaceutical or therapeutic
incompatibilities in the prescription.
• If more than two medicines are prescribed then the pharmacist must see whether
their interactions will produce any harm to the patient or not.
• Certain drugs have interactions with food. The pharmacist has to advise the
patient about it.
• For example,Tetracycline should not be taken with milk or antacid.