1. A pharmaceutical tablet composition of durable action, which comprises: a rapidly precipitating drug in an amount from about 5 to about 60%, and at least one member selected from the group consisting of a binder in an amount of from about 2 to about 25% and a superdisintegrant in an amount from about 6 to about 40% where the rapidly precipitating drug is a relatively soluble or high soluble salt form of a poorly soluble drug, which is free base or free acid. 2. A composition according to claim 1 characterized in that the binder is selected from hydroxypropyl methylcellulose, PVP, hydroxypropyl cellulose, methylcellulose, hydroxyethylcellulose, carbopol, sodium carboxymethylcellulose. 3. A composition according to claim 2 characterized in that the binder is present in an amount as follows for: hydroxypropyl methylcellulose 2 to 20%, PVP 2 to 15%, hydroxypropyl cellulose 5 to 20%, methylcellulose 3 to 20%, hydroxyethylcellulose 5 to 20%, carbopol 3 to 20%, sodium carboxymethylcellulose 3 to 20%. 4. A composition according to claim 2 or 3 characterized in that the binder is hydroxypropyl methylcellulose. 5. A composition according to claim 2 or 3 characterized in that the binder is PVP. 6. A composition according to any of preceding claims characterized in that the superdisintegrant is croscarmellose sodium, sodium starch glycolate, L-hydroxypropyl cellulose. 7. A composition according to any of preceding claims characterized in that the superdisintegrant is present in an amount of from t 6 to 35%. 8. A composition according to claim 7 characterized in that the superdisintegrant is present in an amount of from 10 to 30%. 9. A composition according to any of preceding claims characterized in that it contains microcrystalline cellulose in an amount up to 50%. 10. A composition according to claim 9 characterized in that it contains microcrystalline cellulose in an amount of from 10 to 40%. 11. A composition according to any of preceding claims characterized in that the microcrystalline cellulose is selected from the group consisting of microcrystalline cellulose coarse powder, microcrystalline cellulose medium powder and microcrystalline cellulose 200. 12. A composition according to claim 10 where the microcrystalline cellulose is microcrystalline cellulose N.F. coarse powder. 13. A composition according to any of preceding claims characterized in that it contains lactose in an amount up to about 80%. 14. A composition according to claim 13 where the lactose is present in an amount of from about 5 to about 20%. 15. A composition according to claim 13 or 14 where the lactose is selected from the group consisting of lactose monohydrate spray process standard, lactose monohydrate, lactose anhydrous, lactose dihydrate, DMV lactose. 16. A composition according to claim 15 where the lactose is N.F. monohydrate spray process standard lactose. 17. A composition according to any of preceding claims characterized in that it contains a flow agent in an amount up to 5%. 18. A composition according to claim 17 characterized in that the flow agent is present in an amount from 0.25 to about 2%. 19. A composition according to claim 17 or 18 characterized in that the flow agent is selected from the group consisting of colloidal silicon dioxide and talc. 20. A composition according to claim 19 characterized in that the flow agent is colloidal silicon dioxide N.F. 21. A composition according to any of preceding claims characterized in that contains a lubricant in an amount up to 5%. 22. A composition according to claim 21 characterized in that the lubricant is present in an amount of 0.25 to about 2%. 23. A composition according to claim 21 or 22 characterized in that the lubricant is selected from the group consisting of magnesium stearate and stearic acid. 24. A composition according to claim 23 characterized in that the lubricant is magnesium stearate. 25. A composition according to any of preceding claims characterized in that it contains both a binder and superdisintegrant. 26. A composition according to any of preceding claims characterized in that it contains from 10 to 40%of drug. 27. A composition according to any of preceding claims characterized in that the drug is selected from the group consisting of delavirdine mesylate, phenytoin, furosemide, pseudoephedrine, clindamycin hydrochloride, cloridine hydrochloride, diphenhydramine hydrochloride, fluphenazine hydrochloride, griseofulvin, hydromorphone hydrochloride, naloxone hydrochloride, oxytetracycline hydrochloride, phenylephrine hydrochloride, pheniramine maleate, tetracycline hydrochloride, verapamil hydrochloride, propoxyphene hydrochloride, propoxyphene napsylate, hydrocodine bitartrate, acyclovir sodium, albuterol sulfate, ampicillin sodium, benztropine mesylate, benzphetamine hydrochloride, bupivacaine hydrochloride, bupropin hydrochloride, chlorphenamine maleate, chlorpromazine hydrochloride. 28. A composition according to claim 27 characterized in that the drug is delavirdine mesylate. 29. A composition according to claim 28 characterized in that the delavirdine mesylate is present in an amount of from about 50 to about 300 mg/tablet. 30. A composition according to claim 28 characterized in that the delavirdine mesylate is present in an amount of about 200 or about 300 mg/tablet. 31. A composition according to claim 28, characterized in that it contains 10 to 40% of delavirdine mesylate, 5 to 20% of hydroxypropyl methylcellulose, 6 to 35% of croscarmellose sodium, 10 to 50% of microcrystalline cellulose, 0 to 15% of lactose, 0 to 5% of colloidal silicon dioxide, 0 to 5% magnesium stearate. 32. A composition according to claim 31 characterized in that it contains about30.2% of delavirdine mesylate, about 11.3% of hydroxypropyl methylcellulose 2910 U.S.P. 3 cps, about 16.6% croscarmellose sodium N.F. Type A, about 30.0% of coarse powder microcrystalline Cellulose N.F., about 10.7% of lactose NF monohydrate spray, about 0.23% of colloidal silicon dioxide N.F, about 0.76% of magnesium stearate N.F., powder food grade-V bolted.