5.2 Pharmacokinetic properties
Absorption

Guaifenesin is well absorbed from the gastro-intestinal tract following oral administration, although limited information is available on its pharmacokinetics. After the administration of 600 mg guaifenesin to healthy adult volunteers, the Cmax was approximately 1.4 ug/ml, with tmax occurring approximately 15 minutes after drug administration.

Menthol is well absorbed from the gastrointestinal tract following oral administration.

Distribution

No information is available on the distribution of guaifenesin or menthol in humans.

Metabolism and elimination

Guaifenesin appears to undergo both oxidation and demethylation. Following an oral dose of 600 mg guaifenesin to 3 healthy male volunteers, the t½ was approximately 1 hour and the drug was not detectable in the blood after approximately 8 hours.

Menthol is hydroxylated in the liver by microsomal enzymes to p-methane -3,8 diol. This is then conjugated with glucuronide and excreted both in urine and bile as the glucuronide.

Pharmacokinetics in Renal/Hepatic Impairment

There have been no specific studies of this product, menthol or guaifenesin in hepatic or renal impairment.

Pharmacokinetics in the Elderly

There have been no specific studies in the use of this product, menthol or guaifenesin in the elderly.

5.3 Preclinical safety data
Carcinogenicity

There is insufficient information available to determine whether guaifenesin or menthol have carcinogenic potential.

Mutagenicity

There is insufficient information available to determine whether guaifenesin has mutagenic potential.

The results of a range of tests suggest that menthol does not have a mutagenic potential.

Teratogenicity

There is insufficient information available to determine whether guaifenesin has teratogenic potential.

The results of a number of studies suggest that the administration of menthol does not produce any statistically significant teratogenic effects in rats, rabbits and mice.

Fertility

There is insufficient information available to determine whether guaifenesin or menthol have the potential to impair fertility.

6. Pharmaceutical particulars
6.1 List of excipients
Sodium benzoate (E211)

Sucrose

Liquid glucose

Glycerol

Citric acid monohydrate

Sodium citrate

Saccharin sodium

Ethanol 96%

Caramel T12

Ponceau 4R (E124)

Concentrated raspberry essence double strength

Natural sweetness enhancer

Carbomer

Purified water

6.2 Incompatibilities
None known

6.3 Shelf life
3 years

6.4 Special precautions for storage
Do not store above 30°C.

6.5 Nature and contents of container
125, 150, 200 or 300ml amber glass bottles with a 2 piece or a 3 piece plastic child resistant, tamper evident closure fitted with a polyterephtalate ethylene faced aluminium/expanded polyethylene laminated wad

6.6 Special precautions for disposal and other handling
No special requirements.

Any unused product or waste material should be disposed of in accordance with local requirements.

Administrative data
7. Marketing authorisation holder
McNeil Products Limited

Foundation Park

Roxborough Way

Maidenhead

Berkshire

SL6 3UG

United Kingdom