Film-like or wafer-like medicinal preparation suitable for oral administration of active substances, wherein the preparation contains a matrix composed of at least one matrix-forming polymer and in which at least one bitter-tasting active substance that is absorbable via the oral mucosa or in the stomach and/or intestine and at least one carbon dioxide-forming substance are dissolved or dispersed, characterized in that the carbon dioxide-forming substance is selected from the group comprising sodium hydrogencarbonate, sodium carbonate, potassium carbonate and potassium hydrogencarbonate and is not present in combination with an acid component, and wherein the active substance is selected from the group composed of the antipyretics, laxatives, appetite suppressants, antacids, antiasthmatics, antidiuretics, antiflatulents, migraine agents, psychopharmacological agents, spasmolytics, sedatives, antihyperkinetics, tranquilizers, antihistamines, decongestants, β-receptor blockers, agents for alcohol withdrawal, fluorine supplements, local antibiotics, corticosteroid supplements, agents against goiter formation, antiepileptics, agents against dehydration, antiseptics, acetaminophen, naproxen, gastrointestinal agents, alkaloids, trace element supplements, cholesterol- and lipid-reducing agents, antiarrhythmics, expectorants, xanthines, pyrazolones, α-adrenergic agonists, β-adrenergic agonists, α-adrenergic blockers, aldose reductase inhibitors, anabolics, narcotic analgesics, androgens, anthelminthics, antiacne agents, antiallergics, amoebicidal agents, antiandrogens, agents against angina pectoris, antiatherosclerotic agents, antibiotics, anticholinergics, anticonvulsants, antidepressants, antidiabetic agents, antidiarrheal agents, antidiuretics, antiestrogens, antimycotics, antiglaucoma agents, antigonadotropins, antigout agents, bile acid sequestrants, nicotinic acid derivatives, thyroid hormones, antihypertensive agents, antihyperthyroid agents, antihypothyroid agents, antihypotensive agents, antimalaria agents, antiemetic agents, antineoplastic agents, antiparkinson agents, agents for the treatment of prostatic hypertrophy, antiprotozoal agents, antipruritic agents, antipsoriatic agents, antipsychotic agents, antithrombotics, antitussives, antiulcer agents, uricostatics, antiviral agents, bronchodilators, calcium channel blockers, cardiotonics, cholecystokinin antagonists, cholelitholytic agents, choleretics, cholinergics, cholinesterase inhibitors, cholinesterase reactivators, CNS stimulants, diuretics, dopamine receptor agonists, antiectoparasitic agents, enzymes, enzyme-inducing agents, steroidal and nonsteroidal estrogens, gastric secretion inhibitors, glucocorticoids, gonad-stimulating agents, gonadotropic hormones, growth hormone inhibitors, growth hormone releasing factors, growth stimulants, hemolytic agents, heparin antagonists, hepatoprotective agents, agents for the treatment of liver diseases, immunomodulators, immunosuppressive agents, lactation-stimulating hormones, LH-RH agonists, lipotropic agents, agents against lupus erythematosus, mineralocorticoids, miotics, mucolytics, muscle relaxants, narcotic antagonists, neuroprotective agents, nootropics, ophthalmics, ovarian hormones, oxytocic agents, pepsin inhibitors, peristaltic stimulants, progestogens, prolactin inhibitors, prostaglandins, protease inhibitors, respiratory stimulants, sedatives, hypnotics, thrombolytics, uricosuric agents, vasodilators, vasoprotective agents, vitamins, vitamin precursors and vitamin extracts.