Thursday, June 2, 2011

POTENCY AND DRUG STRENGTH

POTENCY AND DRUG STRENGTH
POTENCY

The products of potentisation are termed as potencies in different degrees.Potency denotes the power that is derived by the grades of medicinal power developed by the process of dynamization. They are a result of series of successive dilution, according to scale and friction through succussion or trituration.

Each stage of dynamization results in a medicine that is quantitatively reduced and qualitatively enhanced. The power generated is termed as 'potency' indicating the potentiality of the medicine.

Representation
The potency of the medicine is indicated by suffixing a numerical and an alphabet(s) to the indicated medicine.

* The numerical indicates the number of times the original drug is subjected to the process of dilution and friction.
* The alphabet indicates the scale under which the dilution is carried out - decimal, centesimal or fifty millesimal

Decimal scale
Decimal scale is denoted by 'X' or 'D' suffixed to the numerical.Hence, when the original drug is potentised once on the decimal scale, it will be represented as 1X or 1D.
If 'Cinchona' is potentised six times on the decimal scale, the power attained by 'Cinchona' will be denoted by 'Cinchona 6X', where 6 means the number of times 'Cinchona' is serially diluted and potentised and 'X' denotes that this potentisation is done according to the decimal scale.

Centesimal scale
Centesimal scale is denoted by 'C' or 'CH' suffixed to the numerical.Hence, when the original drug is potentised once on the centesimal scale, it will be represented as 1C or 1CH.
If 'Cinchona' is potentised six times on the centesimal scale, the power attained by 'Cinchona' will be denoted by 'Cinchona 6C', where 6 means the number of times 'Cinchona' is serially diluted and potentised and 'C' denotes that this potentisation is done according to the centesimal scale.
The potency of medicines prepared according to centesimal scale may also be represented by suffixing only the numerical and omitting the alphabet. Thus, Cinchona, serially diluted and potentised six times on the centesimal scale may be represented also as 'Cinchona 6'.

Fifty Millesimal Scale

* In India and Bangladesh - 0/1, 0/2, 0/3
* Western world - 1/0, 2/0, 3/0
* Hahnemann - 0/1, 0/20/3
* LM1, LM2, LM3

The '0' represents symbolically the poppy sized globule.'L' stands for Fifty and 'M' stands for Millesimal

DRUG STRENGTH
Drug strength signifies the strength of the drug in the given potency.In short, it is the concentration or the amount of the actual drug present in the given potency.
OLD METHOD
Class I = 1/2
Class II = 1/2
Class III = 1/6
Class IV = 1/10

NEW METHOD
Uniform drug strength is 1/10
EXCEPTIONS:
Sulphur = 1/5000
Phosphorus = 1/667
Cactus, Moschus = 1/20
Croton tig, Glonoine = 1/100

CALCULATION OF DRUG STRENGTH

Decimal scale

Potency - 1X
This is prepared by mixing 1 part of the original drug with 9 parts of vehicle. On potentisation, it gives 10 parts of 1X potency of the drug. Hence, 1 part of the original drug is present in 10 parts of 1X potency. Hence the drug strength of 1X potency is 1/10 or 10-1.

Potency - 2X
This is prepared by mixing 1 part of 1X with 9 parts of vehicle. On potentisation, it gives 10 parts of 2X potency of the drug. Hence, 1 part of 1X is present in 10 parts of 2X potency. Hence the drug strength of 2X potency is one-tenth of the strength of 1X potency, that is 1/10 X 1/10 = 1/100 or 10-2.

This can be tabulated as follows
POTENCY STRENGTH
1PX 1/10 = 1/101
2PX 1/100 = 1/102
3PX 1/1000 = 1/103
30PX 1/1030
nth potency - decimal scale 1/10n

Centesimal scale

Potency - 1C
This is prepared by mixing 1 part of the original drug with 99 parts of vehicle. On potentisation, it gives 100 parts of 1C potency of the drug. Hence, 1 part of the original drug is present in 100 parts of 1C potency. Hence the drug strength of 1C potency is 1/100 or 10-2.

Potency - 2C
This is prepared by mixing 1 part of 1C with 99 parts of vehicle. On potentisation, it gives 100 parts of 2C potency of the drug. Hence, 1 part of 1C is present in 100 parts of 2C potency. Hence the drug strength of 2C potency is one-hundredth of the strength of 1C potency, that is 1/100 X 1/100 = 1/10000 = 10-4. ???

This can be tabulated as follows
POTENCY STRENGTH
1PC 1/100 = 1/102 = 1/1001
2PC 1/10000 = 1/104 = 1/1002
3PC 1/1000000 = 1/106 = 1/1003
30PC 1/1060 = 1/10030
nth potency - centesimal scale 1/102n = 1/100n

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