Bernard Birkett
Chief Financial Officer at West Pharmaceutical Services
Thank you, Eric, and good morning. Let's review the numbers in more detail. We'll first look at Q2 2022 revenues and profits, where we saw another strong quarter of sales growth led by performance in our Biologics and Generics market units. I will take you through the profit drivers in the quarter as well as some balance sheet takeaways. And finally, we will provide an update to our 2022 guidance.
First up, Q2. Our financial results are summarized on Slide 8, and the reconciliation of non-U.S. GAAP measures are described in Slides 17 to 20. We recorded net sales of $771.3 million, representing organic sales growth of 13.1%.
Looking at Slide 9. Proprietary Products sales grew organically by 18.3% in the quarter. High-value products, which made up approximately 73% of proprietary product sales in the quarter, grew double-digits and had solid momentum across Biologics and Generics market units in Q2. Looking at the performance of the market units, the Biologics market unit delivered strong double-digit growth. We continue to work with many biotech and biopharma customers who are using West and Daikyo high-value product offerings.
The Generics market unit also experienced strong double-digit growth led by sales of FluroTec and Westar components. Our Pharma market unit saw mid-single-digit growth with sales led by high-value products, including NovaPure components. And contract manufacturing declined 8.9% for the second quarter due to a reduction in sales of components for diagnostic devices. We recorded $321.5 million in gross profit, $6.4 million or 2% above Q2 of last year. And our gross profit margin of 41.7% was a 180 basis point decline from the same period last year. We saw improvement in adjusted operating profit with $227 million recorded this quarter compared to $211.2 million in the same period last year for a 7.5% increase.
And our adjusted operating profit margin of 29.4% was a 20 basis point increase from the same period last year. Finally, adjusted diluted EPS grew $0.01 for Q2, excluding stock-based compensation tax benefit of $0.01 in Q2, EPS grew by approximately 4%.
Let's review the drivers in both revenue and profit. On Slide 10, we show the contributions to sales growth in the quarter. Volume and mix contributed $71.7 million, or 9.9 percentage points of growth and sales price increases contributed $23.4 million or 3.2 percentage points of growth in the quarter.
Looking at margin performance. Slide 11 shows our consolidated gross profit margin of 41.7% for Q2 2022, down from 43.5% in Q2 2021. Proprietary Products' second quarter gross profit margin of 46.2%, 360 basis points lower than the margin achieved in the second quarter of 2021. The decline in Proprietary Products gross profit margin was caused by inflationary pressures impacting all plant costs, including raw materials, labor and overheads. Partially offsetting these inflationary headwinds was improvement in our product mix, price increases and pass through surcharges and approximately 90 basis points of benefit associated with onetime fees from COVID supply agreements.
Contract Manufacturing second quarter gross profit margin of 16.3% was 40 basis points below the margin achieved in the second quarter of 2021. The decrease in margin is largely attributed to mix of products sold in the period.
Now let's look at our balance sheet and review how we've done in terms of generating more cash. On Slide 12, we have listed some key cash flow metrics. Operating cash flow was $324.3 million for the six months ended June 2022, an increase of $91.2 million compared to the same period last year, a 39.1% increase.
Our operating cash flow in the period benefited from increased earnings, our working capital performance and timing of income tax payments. Our second quarter 2022 year-to-date capital spending was $131.9 million, $20.3 million higher than the same period last year. Working capital of approximately $1.2 billion at June 30, 2022, increased by $58.1 million from December 31, 2021, primarily due to increases in accounts receivable and inventory offset by reductions in our cash. Our cash balance at June 30, $718.5 million, was $44.1 million lower than our December 2021 balance. The decrease in cash is primarily due to our share repurchase program and higher capex offset by our strong operating cash flow in the period.
Turning to guidance. Slide 13 provides a high-level summary. We are updating our full year 2022 net sales guidance and expect net sales to be in a range of $2.95 billion and $2.975 billion compared to our prior guidance range of $3.05 billion to $3.075 billion. There is an estimated headwind of $190 million based on current foreign exchange rates compared to a prior estimated headwind of $115 million. We expect organic sales growth to be approximately 11% compared to prior guidance of approximately 11% to 12%. We expect our full year 2022 adjusted diluted EPS guidance to be in a range of $9 to $9.15 compared to a prior range of $9.30 to $9.45. This revised guidance includes our first half $0.13 EPS positive impact of tax benefits from stock-based compensation.
Also, our capex guidance remains at $380 million for the year. There are some key elements I want to bring your attention to as you review our guidance. Estimated FX headwind on EPS has an increased impact of approximately $0.55 based on current foreign currency exchange rates, compared to a prior estimated headwind of $0.38. We expect full year COVID-19-related sales to be approximately $85 million lower than 2021 sales. And our guidance excludes future tax benefits from stock-based compensation.
To summarize the key takeaways for the quarter, strong top line growth in proprietary, growth in operating profit, solid adjusted diluted EPS, despite FX and inflationary headwinds and growth in operating cash flow, delivering in line with our pillars of execute, innovate and grow.
I would now like to turn the call back over to Eric.
