President Reagan last week called Democratic charges of widespread corruption in his administration "pure demagoguery." Asked about the more than 100 people who have left the administration under a cloud or whose nominations have been defeated or withdrawn, Reagan cited the recent acquittal of former labor secretary Raymond J. Donovan and said he would "challenge" any claim that the administration lacks integrity.

Following is an update on senior administration officials and persons involved in the Iran-contra affair who have faced criminal charges since 1981: ETHICS IN WASHINGTON

MICHAEL K. DEAVER, former White House deputy chief of staff, was indicted for perjury in March and is awaiting trial next month. Deaver is charged with five counts of lying to a House subcommittee and a federal grand jury about his lobbying activities for Canada, Puerto Rico, South Korea and other clients after leaving the White House in 1985. Deaver, who faces a maximum sentence of 25 years in prison and $34,000 in fines if convicted, has pleaded not guilty.

C. MCCLAIN HADDOW, former chief of staff at the Department of Health and Human Services, was indicted in April on charges of fraudulently obtaining more than $30,000 from the nonprofit T. Bear Foundation, which he helped create, through payments funneled to his wife. The seven-count indictment also charged Haddow with taking kickbacks on $25,500 in HHS payments for 14 speeches written for his boss, then-Secretary Margaret M. Heckler. Haddow, who could face 12 years in prison and $271,000 in fines if convicted, has pleaded not guilty and is awaiting trial next month.

JAMES M. BEGGS, former head of the National Aeronautics and Space Administration, has been cleared of charges that he defrauded the government while an executive at General Dynamics Corp. The Justice Department dropped the charges last week and admitted that its theory of prosecution was wrong. Beggs and the company were indicted in December 1985 on charges of fraudulently hiding cost overruns on an Army contract to develop the Divad antiaircraft gun.

RAYMOND J. DONOVAN, former secretary of labor, was acquitted last month of 1984 charges that he and his construction company defrauded the New York City Transit Authority of $7.4 million on a still-unfinished Manhattan subway tunnel. Donovan, who was accused of working with a phony minority business company run by a reputed Mafia soldier, was cleared after a lengthy trial.

RITA M. LAVELLE, former head of the Environmental Protection Agency's toxic-waste cleanup program, was convicted in 1984 of lying about the date on which she learned that her former employer, Aerojet-General Corp., had dumped wastes at a California site under investigation by EPA. Lavelle, also convicted of obstructing a congressional inquiry, served part of a six-month prison term.

PETER E. VOSS, former vice chairman of the U.S. Postal Service Board of Governors, pleaded guilty last year to accepting at least $30,000 in kickbacks on four postal contracts that he helped influence. Voss also admitted pocketing at least $43,000 by submitting fraudulent expense vouchers. He was sentenced to four years in prison and fined $11,000.

PAUL THAYER, former deputy secretary of defense, pleaded guilty in 1985 to obstructing justice and giving false testimony about an insider stock-trading scheme that netted eight of his friends more than $1.5 million in illegal profits. Thayer leaked confidential information about companies of which he was a director to his girlfriend, his Dallas stockbroker and others. Thayer served 19 months of a four-year prison term.

THOMAS C. REED, a former White House adviser to Reagan, was acquitted in 1985 of insider stock-trading charges. Reed, a former Air Force secretary, turned a $3,000 investment in his father's company into a $431,000 profit in 48 hours, but denied that he had used inside information from his father, a company director, about a merger offer that boosted the value of the firm's stock.

GEORGE A. SAWYER, former assistant Navy secretary, was acquitted in 1985 of charges of violating conflict-of-interest laws and lying about the circumstances under which he negotiated a job as a General Dynamics Corp. vice president. Sawyer was indicted on charges of concealing that he flew to job interviews at General Dynamics at the company's expense while still supervising its Navy shipbuilding contracts.

J. WILLIAM PETRO, former U.S. attorney in Cleveland, was convicted of criminal contempt for violating grand jury secrecy and fined $7,500. Petro, who had been fired by Reagan, was charged with telling a friend that the man's associates had been named in a sealed indictment for selling counterfeit merchandise.

Also under investigation by separate independent counsels are:

Attorney General EDWIN MEESE III and former White House aide LYN NOFZIGER, who are alleged to have improperly helped the Wedtech Corp. and other companies win federal contracts. Former White House aide OLIVER L. NORTH and a host of others in the probe of how profits from U.S. arms sales to Iran were diverted to the Nicaraguan contras. Former assistant attorney general THEODORE B. OLSON, who is alleged to have given false testimony to Congress during a 1983 dispute over Environmental Protection Agency documents. Former assistant attorney general W. LAWRENCE WALLACE, who resigned last year after his personal finances came under investigation.