OMP Inc., a Long Beach-based pharmaceutical company that develops products for "skin, health and restoration," lowered the target proceeds it expects to garner in an initial stock offering, according to a regulatory filing. OMP amended its registration statement with the Securities and Exchange Commission and disclosed its plans to sell 4.5 million shares for an estimated $11 to $13 each. In a similar filing last week, the company said those shares would sell for $14 to $16. OMP markets products that physicians can use to treat such problems as sun damage, acne and wrinkles. In its SEC filing, OMP said an economic slump and slowing consumer spending could affect sales. OMP's products generally are not covered by insurance, the company said.