Pollution prevention in the pharmaceutical industry

Figures & data

Table 1 Waste streams of pharmaceutical processes.

Process origin	Waste description	Composition
R&D	Used chemicals	Different chemicals
Boilers	Combustion products	CO, NOx and SO2
Fermentation	Spent fermentation broth	Polluted water
Extraction	Spent aqueous/solvent solutions	Contaminated water
		Contaminated solvents
Organic synthesis	Process liquors	Contaminated solvents
Natural product extraction	Spent feedstock	Leaves, tissues, etc.
Product handling	Containers, bags, bottles	Contaminated solid waste (fibre, plastic, metal, cardboard, etc.)
Storage tanks, reactors, product handling	Venting VOCs	VOCs
Equipment cleaning, spills, residues, scrubbers	Waste water	Various pollutants
Production materials	Filters, piping, filtration aids, etc.	Mostly segregated solid waste
Manufacturing	Off-spec products, outdated products and spent solvents	Different products

Source: Adapted from PhRMA (2012).

Figure 1a The Boots company synthesis of ibuprofen – the ‘brown’ synthesis.

Figure 1b The BHC company synthesis of ibuprofen – the ‘green’ synthesis.

Table 2 Atom economies of the ibuprofen synthesis by a ‘brown’ and ‘green’ manufacturing process.

	Reagent		Utilised in ibuprofen		Unutilised in ibuprofen
	Formula	FW	Formula	FW	Formula	FW
(a) The ‘brown’ synthesis of ibuprofen: atom economy =  (FW ibuprofen/FW all reactants) × 100% = (206/514.5) × 100% = 40%
1	C10H14	134	C10H13	133	H	1
2	C4H6O3	102	C2H3O	43	C2H3O2	59
4	H2	2	H2	2	–	0
6	CO	28	CO	28	–	0
Total			Ibuprofen		Waste products
	C15H22O4	266	C13H18O2	206	C2H4O2	60
1	C10H14	134	C10H13	133	H	1
2	C4H6O3	102	C2H3	27	C2H3O3	75
4	C4H7ClO2	122.5	CH	13	C3H6ClO2	109.5
5	C2H5ONa	68	–	0	C2H5ONa	68
7	H3O	18	–	0	H3O	19
9	NH3O	33	–	0	NH3O	33
12	H4O2	36	HO2	33	H3	3
Total			Ibuprofen		Waste products
	C20H42NO10ClNa	514.5	C13H18O2	206	C7H24NO8ClNa	308.5
(b) The ‘green’ synthesis of ibuprofen: atom economy = (FW ibuprofen/FW all reactants) × 100% = (206/266) × 100% = 77%
1	C10H14	134	C10H13	133	H	1
2	C4H6O3	102	C2H3O	43	C2H3O2	59
4	H2	2	H2	2	–	0
6	CO	28	CO	28	–	0
Total			Ibuprofen		Waste products
	C15H22O4	266	C13H18O2	206	C2H4O2	60

Note: FW = formula weight.

Table 3 Waste reduction in the pharmaceutical industry.

Waste stream	Possible actions
Air pollutants	• Reduce tank/reactor vents• Use appropriate emission abatement techniques (condensers, scrubbers, recuperation, incineration, etc.)• Reduce solvent use• Reduce N2 purge rates• Apply activated carbon/gas membranes on vents
Water pollutants	• Reduce frequency of equipment cleaning• If possible consider continuous processing• Use countercurrent filtration and washing• Remove leftover solvents/aqueous solutions by plug-cleansing of piping• Substitute persistent solvents by less hazardous ones, or use aqueous systems when possible
Solid waste	• Use containers with internal liners• Segregate waste• Return packaging to supplier• Rework off-spec material (if tolerable)

Source: Adapted from Everaert and Baeyens (2008).

PhRMA, 2012. Available from: http://www.phrma.org/illustrative-pharmaceutical-lifecycle (consulted on 27 July 2012).

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Everaert, K. and Baeyens, J., 2008. The pharmaceutical industry, Preventieve Pollutiebeperking van Processen. Belgium: Wolters Kluwer, 123–129, ISBN 978-90-4651-959-2 (in Dutch), Chapter 4.

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