doxycycline hyclate std The pharmaceutical composition of claim 7, wherein the ionic surfactant is selected from the group consisting of lecithin, lysolecithin, phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, phosphatidic acid, phosphatidylserine, lysophosphatidylcholine, lysophosphatidylethanolamine, dysophosphatidylglycerol, lysophosphatidic acid, lysophosphatidylserine, PEG phosphatidylethanolamine, PVP phosphatidylethanolamine, lactylic esters of fatty acids, stearoyl 2 lactylate, stearoyl lactylate, succinylated monoglycerides, mono diacetylated tartaric acid esters of mono diglycerides, citric acid esters of mono diglycerides, cholate, taurocholate, glycocholate, deoxycholate, taurodeoxycholate, chenodeoxycholate, glycodeoxycholate, glycochenodeoxycholate, taurochenodeoxycholate, ursodeoxycholate, lithocholate, tauroursodeoxycholate, glycoursodeoxycholate, cholylsarcosine, N methyl taurocholate, caproate, caprylate, caprate, laurate, myristate, palmitate, oleate, ricinoleate, linoleate, linolenate, stearate, lauryl sulfate, tetraacetyl sulfate, docusate, lauroyl carnitine, palmitoyl carnitine, myristoyl, carnitine, and salts and mixtures thereof