LONDON -- The world's fifth-largest pharmaceutical company, with operations in more than a hundred countries worldwide, AstraZeneca (LSE: AZN.L) (NYSE: AZN) is a business with very definite attractions. A 36-billion-pound FTSE 100 constituent, last year the company earned a pre-tax profit of $12.4 billion on revenues of $34 billion.

And with margins like that, it's no wonder that this defensively-positioned business is popular with many investors. Today, with its shares changing hands at 2,892 pence, the company is rated on a cheap-looking prospective price-to-earnings ratio of 8, and offers income investors a very tempting forecast dividend yield of 6.4%.

But how safe is that share price? And -- of vital importance to income investors -- how safe is that dividend? In short, how could an investment in AstraZeneca adversely impact investors' wealth?

In this series, I set out to answer just these questions. My starting point: AstraZeneca's latest annual report, where the company's directors are obliged to address the issue of risk.

Risk management
One immediate thing that I'm looking for is an acknowledgement that risks do exist and that they need managing.

The good news? As you'd expect from a business of AstraZeneca's size and caliber, the company has in place a risk management policy, a system of regular reviews, and a number of high-level committees tasked with monitoring the risks that the business has identified.

But what, precisely, are those risks that the company faces?

Read the small print, and AstraZeneca identifies no fewer than 29 risks as having a significant prospective impact on the company's financial performance. They range from delayed regulatory approvals to taxation, and from illegal trade in its products to patent litigation.

So let's take a look at three of the biggest.

Failure to meet development targets
Fairly obviously, AstraZeneca's shares are cheap -- and the prime reason for this is to do with investors' worries over its product pipeline. In short, this is seen as weak, with insufficient new products coming on stream as patents expire on old ones. As AstraZeneca puts it:

The development of any pharmaceutical product candidate is a complex, risky and lengthy process involving significant financial, R&D and other resources, which may fail at any stage of the process due to a number of factors. A succession of negative drug project results and a failure to reduce development timelines effectively or produce new products that achieve commercial success could adversely affect the reputation of our R&D capabilities, and is likely to materially adversely affect our financial condition and results of operations.

In many ways, it was the perceived failure of former chief executive David Brennan to get to grips with this issue that led to his removal earlier this year. And there's no doubt that investors are worried: Sales during the three months to the end of September slid almost 20%, thanks to the patent expiries of treatments such as the antipsychotic Seroquel. That said, new chief executive Pascal Soriot -- who joined the company from Roche -- is well aware of the problem, as is the rest of the board.

Delay to new product launches
In the pharmaceutical business, patenting a new treatment is one thing, and bringing it to market in a timely manner quite another. As the company puts it:

The anticipated launch dates of major new products have a significant impact on a number of areas of our business, including investment in large clinical studies, the manufacture of pre‑launch product stocks, investment in marketing materials pre‑launch, sales force training and the timing of anticipated future revenue streams from new product sales. For example, for the launch of products that are seasonal in nature, delays in regulatory approvals or manufacturing difficulties may delay launch to the next season which, in turn, may significantly reduce the return on costs incurred in preparing for the launch for that season.

In short, execution is everything -- as the company knows too well. One slip, and the hit to revenues is almost unavoidable. AstraZeneca knows the dangers, to be sure. But can it avoid them? Time will tell.

Price controls
In many countries, health care costs consume an increasing amount of GDP. Consumers and legislators alike are aware of this, and in the present economic environment it's no surprise that pressures are mounting on health care providers, health care insurers and legislators to promote the use of cheaper generic drugs where possible. As AstraZeneca notes:

Most of our key markets have experienced the implementation of various cost control or reimbursement mechanisms in respect of pharmaceutical products. For example, in the United States, realised prices are being depressed through cost‑control tools such as restricted lists and formularies, which employ 'generic first' strategies, and require physicians to obtain prior approval for the use of a branded medicine where a generic version exists.

The pressures are very real, and there's no doubt that the increasingly restrictive reimbursement policies to which AstraZeneca is subject -- together with the potential adoption of new legislation expanding the scope of permitted commercial importation of medicines into the United States -- could materially adversely affect the firm's financial performance.

What can the company do? Innovate, in short. But it's little wonder that in a 'head to head', many investors favour competitor GlaxoSmithKline precisely because of its clutch of consumer healthcare and nutrition products -- which generate a decent 20% of sales -- and which come from such brands as Panadol, Sensodyne, Macleans, Lucozade, and Horlicks.

Risk vs. reward
Two superstar investors who are well-used to weighing risks are Neil Woodford and Warren Buffett.

On a dividend-reinvested basis over the 15 years to Dec. 31, 2011, Neil Woodford delivered a return of 347%, versus the FTSE All‑Share's distinctly more modest 42% performance. Warren Buffett, for his part, has delivered returns of over 20% per annum since 1965, transforming himself into the world's third-wealthiest person.

Each, as it happens, are the subject of two special reports prepared by Motley Fool analysts. And they're yours to freely download, without any obligation.

So click here to download this free special report profiling the investment logic behind eight of Woodford's largest and most successful current picks.

And click here to discover which beaten-down British share Warren Buffett has been buying of late -- and why he bought it, and the price he paid.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.