Novel encochleation methods, cochleates and methods of use

Abstract

Disclosed are novel methods for making cochleates and cochleate compositions that include introducing a cargo moiety to a liposome in the presence of a solvent. Also disclosed are cochleates and cochleate compositions that include an aggregation inhibitor, and optionally, a cargo moiety. Additionally, anhydrous cochleates that include a protonized cargo moiety, a divalent metal cation and a negatively charge lipid are disclosed. Methods of using the cochleate compositions of the invention, including methods of administration, are also disclosed.

Description

TECHNICAL FIELD The invention generally relates to cochleate delivery vehicles. More specifically, the invention relates to novel methods of making and using cochleates employing a solvent to encochleate a cargo moiety, to cochleates including one or more aggregation inhibitors, and to cochleates including a protonized cargo moiety, divalent cation and negatively charged lipid. BACKGROUND The advantages of cochleates are numerous. For example, cochleates are more stable than aqueous structures such as liposomes, they can be stored lyophilized which provides the potential to be stored for long periods of time at room temperatures, they maintain their structure even after lyophilization (whereas liposome structures are destroyed by lyophilization), and they are non-toxic. Cochleate structures have been prepared first by D. Papahadjopoulos as an intermediate in the preparation of large unilamellar vesicles. U.S. Pat. No. 4,078,052. Methods of making and using cochleates to deliver a...

AI Technical Summary

Benefits of technology

Another advantage of the present invention is the ability to modulate cochleate size. Modulation of the size of cochleates and cochleate compositions changes the manner in which the cargo moiety is taken up by cells. For example, in general, small cochleates are taken up quickly and efficiently into cells, whereas larger cochleates are taken up more slowly, but tend to retain efficacy for a longer period of time. Also, in some cases small cochleates are more effective than large cochleates in certain cells, while in other cells large cochleates are more effective than small cochleates.

is the ability to modulate cochleate size. Modulation of the size of cochleates and cochleate compositions changes the manner in which the cargo moiety is taken up by cells. For example, in general, small cochleates are taken up quickly and efficiently into cells, whereas larger cochleates are taken up more slowly, but tend to retain efficacy for a longer period of time. Also, in some cases small cochleates are more effective than large cochleates in certain cells, while in other cells large cochleates are more effective than small cochleates.

Cochleates and cochleate compositions can also be administered to humans and non-human animals, such as dog, cats, and farm animals, in food or beverage preparations. Such compositions can be introduced to the food or beverage compositions by the manufacturer (e.g., to supplement food with nutrients), or by the consumer (e.g., where the cochleate composition is sold separately as a food additive). For example, nutrients and / or flavorings may be incorporated into dog or cat food, particularly where such nutrient and / or flavoring is fragile and normally decomposes or loses, activity when exposed to oxygen and or water. Cochleates may be added at any stage into the preparation of dog or cat food, as the cochleates are stable under extreme pressure and temperature conditions.

Another advantage of cochleates and cochleate compositions of the present invention is their ability to reduce a number of unwanted side effects. A number of drugs currently on the market cause gastrointestinal distress and often high circulating blood levels lead to toxicity in a number of vital organs. The ingestion of, e.g., aspirin may result in epigastric distress, nausea, and vomiting. Aspirin may also cause gastric ulceration; exacerbation of peptic ulcer symptoms, gastrointestinal hemorrhage, and erosive gastritis have all been reported in patients on high-dose therapy but also may occur even when low doses are administered. In high doses, aspirin can also cause hepatic injury. Aspirin can cause retention of salt and water as well as an acute reduction of renal function in patients with congestive heart failure or renal disease. Although long-term use of aspirin alone rarely is associated with nephrotoxicity, the prolonged and excessive ingestion of aspirin in combination with other compounds can produce papillary necrosis and interstitial nephritis. Although acetaminophen is usually well tolerated, skin rash (generally erythematous or urticarial) `and other allergic reactions occur occasionally. Occasionally, the rash can be more serious and may be accompanied by drug fever and mucosal lesions. In other examples, the use of acetaminophen has been associated with neutropenia, thrombocytopenia, and pancyotpenia. The most serious adverse effect of acute overdosage of acetaminophen is a dose-dependent, potentially fatal hepatic necrosis. Renal tubular necrosis and hypoglycemic coma also may occur.

Another advantage of the present invention is that the cochleates can be formulated for uptake by particular cells or organs. Conventionally, high levels of drugs are often administered intravenously to obtain moderate levels at the sites of infection in order to combat opportunistic infections. This can cause undesirable side effects, for example, in the case of vancomycin, macular skin rashes, anaphylaxis, phlebitis and pain at the site of intravenous injection, chills, rash, and fever may occur. Also, rapid intravenous infusion may cause a variety of symptoms, including erythematous or urticarial reactions, flushing, tachycardia, and hypotension, generally non-permanent auditory impairment, ototoxicity associated with excessively high concentrations of the drug in plasma and less commonly, nephrotoxicity. By employing the cochleates of the present invention, toxicity levels can be lowered by decreasing the free drug in the circulating blood. Additionally, the cargo moiety can be delivered directly to the site of infection, which can lower or eliminate the incidence of gastrointestinal distress.

Aminoglycosides are very poorly absorbed from the gastrointestinal tract. Less than 1% of the dose typically is absorbed following either oral or rectal administration. Also, inadequate concentrations of aminoglycosides are found in cerebrospinal fluid. Additionally, the drugs are not inactivated in the intestine, and are excreted relatively rapidly by the normal kidney, i.e., they are eliminated quantitatively in the feces. Long-term oral or rectal administration, however, may result in accumulation of aminoglycosides to toxic concentrations in patients with renal impairment. Instillation of these drugs into body cavities with serosal surfaces may result in rapid absorption and unexpected toxicity, i.e., neuromuscular blockade. Similarly, intoxication may occur when aminoglycosides are applied topically for long periods to large wounds, burns, or cutaneous ulcers, particularly if there is renal insufficiency.

Problems solved by technology

These steps are time consuming, represent added expense in manufacturing and product costs, and can in some instances affect the activity and / or stability of the encochleated material.

Additionally, cochleates are highly susceptible to aggregation, and thus particle size and particle size distribution can be highly variable and unstable after preparation and removal from the two-phase polymer system.

For example, aminoglycopeptides (e.g., vancomycin), are poorly absorbed through the GI tract and are difficult to deliver to cells harboring bacteria.

Accordingly, in order to administer an effective amount of drug against a bacterial infection, large amounts of drug are ingested to not only account for poor absorption through the GI tract, but also poor delivery to the site of infection.

Consequently, a toxic level of drug can accumulate in the GI tract (e.g., in the kidneys) or the blood stream and can lead to serious illness, such as erythematous or urticarial reactions, flushing, tachycardia, and hypotension.

Aminoglycosides (e.g., streptomycin and tobramycin) are similarly problematic because of the risk of nephrotoxicity and ototoxicity due to poor absorption, which can lead to acute, renal, vestibular and auditory toxicity.

While these drugs can be delivered intravenously to bypass the issue of poor GI tract absorption, uptake by the cells is still problematic.

Additionally, echinocandins (e.g., caspofungin), a new, less toxic class of antifungal drugs, still have unwanted side effects and poor oral bioavailability.

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