# Small-molecule APIs: Correlation Prices it moves with, and why Source page: https://www.materialinsights.org/chemicals/apis/correlation/ Small-molecule active pharmaceutical ingredients are made in multi-step syntheses from starting materials and intermediates, largely sourced from China. Generic API prices reflect intermediate costs, plant compliance and competition, and move slowly on long contracts. Price index **US PPI: synthetic organic medicinal chemicals and botanical drugs** index (BLS base period =100) · monthly, Jan 2006 to Sep 2026 #### What its price moves with Selected link ##### Small-molecule APIs and Antibiotic intermediates (6-APA, 7-ACA) Monthly changes -0.03 little or none correlation 12-month changes -0.08 little or none correlation Last 5 years 0.19 monthly changes Lead or lag +1 mo Antibiotic intermediates (6-APA, 7-ACA) tends to lead by 1 month (r 0.11) Price function, Dec 2009 to Sep 2026 Small-molecule APIs ≈ 111.8 × (Antibiotic intermediates (6-APA, 7-ACA))^0.10 R² 0.32 On this fit, a 10% higher Antibiotic intermediates (6-APA, 7-ACA) price goes with a 0.9% higher Small-molecule APIs price over the long run. Units: index (BLS base period =100) and index (BLS base period =100). Chart: Small-molecule APIs and Antibiotic intermediates (6-APA, 7-ACA) prices rebased to 100 at Dec 2009, log scale Both prices rebased to 100 at Dec 2009, on a log scale so equal percentage moves look the same size. Chart: Small-molecule APIs price against Antibiotic intermediates (6-APA, 7-ACA) price, monthly, log scales, with fitted line Each dot is one month; paler dots are older (2009), darker dots recent (2026); the ringed dot is the latest month. The dashed line is the fitted price function. Both axes are logarithmic. Chemical [KSM Pharma starting materials and intermediates](https://www.materialinsights.org/chemicals/ksm_intermediates/)Main input Key starting materials and intermediates make up a large part of generic API cost, and India still imports most of them from China. Both use the same medicinal chemicals index here, so no separate statistics are shown for this pair. Not enough overlapping price history to measure. Chemical [6APA Antibiotic intermediates (6-APA, 7-ACA)](https://www.materialinsights.org/chemicals/antibiotic_intermediates/)Sister input chain −0.03 Antibiotic APIs are built from fermentation intermediates such as 6-APA, a separate chain from synthetic APIs. The antibiotics proxy correlates at -0.03 for monthly moves and 0.19 over the last five years, so the two chains price largely independently. little or none co-movement month to month · 202 months Show charts Chemical [MeOH Methanol](https://www.materialinsights.org/chemicals/methanol/)Solvent cost −0.01 API synthesis uses large volumes of solvents such as methanol, acetone and toluene, often recovered and reused. Against the organic chemicals proxy, monthly moves correlate at -0.01 and yearly at 0.15, as solvents are a modest cost. little or none co-movement month to month · 249 months Show charts Energy [Oil Crude oil](https://www.materialinsights.org/energy/crude_oil/)Distant feedstock 0.07 Most API building blocks start from petrochemicals, but many steps, regulation and long contracts separate them from oil. Monthly moves correlate at 0.07 and yearly at -0.11, so oil barely registers in the medicinal chemicals index. little or none co-movement month to month · 249 months Show charts Chemical [APAP Paracetamol](https://www.materialinsights.org/chemicals/paracetamol/)Product example Paracetamol is a high-volume API whose price swings with its intermediate, para-aminophenol, and with Chinese supply. It shows how commodity-like some generic APIs can be, unlike the stable pricing seen in the overall index. Not enough overlapping price history to measure. Chemical [Exc Pharmaceutical excipients](https://www.materialinsights.org/chemicals/excipients/)Formulation partner APIs are combined with excipients such as cellulose, starch and lactose to make tablets and capsules. Both are bought by the same formulation companies and follow generic drug output in India and elsewhere. Not enough overlapping price history to measure. How to read these numbers **Correlation of monthly changes** (the number in the coloured pill) compares how much each price moved, month by month, since 2006 or the first month both series exist. It runs from −1 to +1: near +1 the two usually rise and fall in the same months, near 0 there is no link, and a negative number means they tend to move in opposite directions. Above 0.7 is strong, 0.4 to 0.7 moderate, 0.2 to 0.4 weak. **12-month changes** compare year-on-year moves, which shows whether two prices share the same cycles even when the month-to-month noise differs. **Price function** is a straight-line fit of the two prices on logarithmic scales: price ≈ k × (partner price)^β. β is how much this price moves, in per cent, for a 1% move in the partner over the whole period, and R² is the share of the variation the fit explains. Two prices that both drift up with inflation can fit well without any real link, so read it together with the monthly correlation. **Lead or lag** checks whether the monthly correlation is clearly higher when one price is shifted by 1 to 6 months. Correlation is not cause. The reasons on each card explain the economic link; the numbers show how strongly it has shown up in prices. Proxy series are US producer price indexes or related prices and can blur the real link. Data: World Bank Commodity Price Data (Pink Sheet), October 2026; US Bureau of Labor Statistics producer price indexes, IMF primary commodity prices and US EIA prices via FRED, Federal Reserve Bank of St. Louis, retrieved November 2026. Calculations by this site. ## Other sections - [Summary](https://www.materialinsights.org/chemicals/apis/index.md) - [Overview](https://www.materialinsights.org/chemicals/apis/overview/index.md) - [Production route](https://www.materialinsights.org/chemicals/apis/routes/index.md) - [Production](https://www.materialinsights.org/chemicals/apis/production/index.md) - [Feedstocks](https://www.materialinsights.org/chemicals/apis/feedstocks/index.md) - [Cycles](https://www.materialinsights.org/chemicals/apis/cycles/index.md) - [Trading](https://www.materialinsights.org/chemicals/apis/trading/index.md) - [Movement](https://www.materialinsights.org/chemicals/apis/movement/index.md) - [Regulation](https://www.materialinsights.org/chemicals/apis/regulation/index.md) - [Characteristics](https://www.materialinsights.org/chemicals/apis/characteristics/index.md) - [Emissions](https://www.materialinsights.org/chemicals/apis/emissions/index.md) - [Relationships](https://www.materialinsights.org/chemicals/apis/links/index.md)