A pharmaceutical composition

Abstract: A pharmaceutical product preferably in the form of a capsule comprises in one case Atenolol and Aspirin. A barrier film coating including a dihydric alcohol is provided around a tablet of Atenolol which in turn is surrounded by Aspirin inside a capsule. Aspirin is preferentially and maximally absorbed in the first hour after ingestion before significant release and absorbtion of Atenolol.

Description: The invention relates to a pharmaceutical composition. Pharmaceutical compositions comprising salicylic acid derivatives and anti-hypertensive agents are known from EP-A-0219728 and EP-A-0214881. According to one aspect of the invention there is provided a pharmaceutical composition comprising: a first pharmaceutically active ingredient comprising salicylate or a salt, ester, derivative, complex thereof, or salts of the ester, derivative or complex, said first ingredient having anti-platelet activity; a second pharmaceutically active ingredient comprising a β-blocker which interacts with the first ingredient; and a barrier between the first and second active ingredients to substantially prevent interaction therebetween in the composition. The use of a barrier substantially prevents interaction between the active ingredients and degradation of the composition. Thus, a chemically and physically stable dosage form is provided. In a preferred embodiment of the invention the barrier includes cellulosic material. Advantageously, the barrier includes as a plasticiser a pharmaceutically acceptable alkyl mono or poly alcohol or ether which is compatible with the active ingredients. In a preferred embodiment of the invention the plasticiser comprises a glycol, most preferably propylene glycol. This composition is especially advantageous as it provides a barrier film coating which contains as a plasticiser a material which is compatible with salicylates and produces an especially chemically and physically stable dosage form. In a particularly preferred embodiment of the invention the second active ingredient comprises the β-blocker atenolol. The salicylate may be present in a powder or granular form. Advantageously, the salicylate comprises aspirin which may be present in any desired form. One complex which may be preferred for ease of solubility is the complex of calcium aspirinate and urea. In a particularly preferred embodiment of the invention the salicylate comprises aspirin, the second active ingredient comprises atenolol, and the weight ratio of aspirin to atenolol in the composition is from 1:2 to 6:1, most preferably approximately 3:1. In an especially preferred embodiment of this aspect of the invention the composition is in a form suitable for oral administration, most preferably in the form of a capsule. Advantageously, the β-blocker is in the form of a tablet, a barrier is provided around the tablet and the anti-platelet agent surrounds the tablet in the capsule. The invention will be more clearly understood from the following embodiments thereof given by way of example only with reference to the accompanying drawings, in which:- Fig. 1 is a graph of in-vitro dissolution over time of an Atenolol tablet used in one composition of the invention in comparison with a commercially available atenolol tablet, Fig. 2 is a graph of in vivo absorbtion over time of an atenolol tablet used in one composition of the invention in comparison with the absorbtion of a commercially available tenolol tablet over an initial 3 hour period, and Fig. 3 is a graph of in vivo absorbtion over time of an acenolol tablet used in one composition of the invention in comparison with the absorbtion of a commercially available Atenolol tablet over a 24 hour period. Example 1 A capsule according to the invention was formulated as follows: A. Atenolol Tablet The following amounts of atenolol and excipients and vehicles were mixed together and the mixture thus formed was compressed in a tablet press to form tablets which were approximately 6 mm in diameter, approximately 2.5 mm to 3 mm thick and weighed approximately 80 mg. Quantities for 1,000 tablets Atenolol 50.0 g Maize Starch 4.0 g Microcrystalline Cellulose 21.2 g Sodium Starch Glycolate 4.0 g Magnesium Stearate 0.8 g Distilled Water minimum amount required. The maize starch is added to warmed distilled water and boiled water is added to the solution thus formed and mixed. The atenolol and microcrystalline cellulose are mixed and the starch solution is then added until a granulate is formed which is then dried and sieved. The sodium starch glycolate is then added followed by the magnesium stearate. Tablets are then formed by a tabletting machine by conventional techniques. B. Coating Material The coating material used was a cellulosic material (a pharmaceutically acceptable alkyl cellulose derivative) using proplyene glycol as plasticiser. The solvent may be aqueous or organic. The atenolol tablet of A was coated with this coating material by conventional techniques. C. Aspirin 150 mg of granulated aspirin such as type RC3 available from Rhone Poulenc was used for each capsule. D. Capsule The capsule is of a conventional capsule material such as hard gelatin material. Combination Product An 80 mg atenolol tablet from A. coated with the coating material of B was placed in the capsule of D and surrounded by the granulated aspirin of C. To monitor the in vitro and in vivo properties of the coated Atenolol tablets, of the composition of the invention and conventional atenolol tablets [TENORMIN (registered trade mark of ICI)] the tablets were first tested in vitro and the results are plotted in Fig. 1. Tests for absorption in vivo was also carried out and the results are plotted in Figs. 2 and 3. Fig. 2 is on an expanded scale to Fig. 3. As will be apparent from Figs. 1, 2 and 3, the atenolol tablet used in the composition of the invention differs from conventional atenolol tablets as regards drug release characteristics. The retarded initial release of atenolol is demonstrated in vitro in Fig. 1 and is reflected in the significant time delay or lag in the onset of absorption in vivo as will be apparent from Figs. 2 and 3. Consequently, the more rapidly absorbed aspirin is preferentially and maximally absorbed in the first half hour after ingestion of the capsule of the Example above, at a time before significant release and absorption of atenolol. Further in vivo data was obtained for the combination product of Example 1. This data demonstrated that a time lag was sustained in the presence of aspirin. The aspirin absorption was much more rapid as reflected by the peak plasma level for spirin which occurred approximately at ½ hour to one hour after administration. The dissolution and absorption time lag of the atenolol used in the composition of the invention is exploited to facilitate absorption of the aspirin. Thus, the bioavailability of both drugs is optimised. Any possibility of adverse interaction in vivo arising on concomitant release of both drugs in the gastrointestinal tract is also avoided. Thus, the release/dissolution and absorption of aspirin occurs first and to a substantial extent before the release and absorption of atenolol thereby reducing the likelihood of in vivo adverse effects or patient injury. Further, in medical practice, the composition of the invention has the considerable advantage of providing a single dose pharmaceutical product which combines anti-platelet action and anti-hypertensive action. As a single product only is required the product is particularly advantageous from the point of view of compliance. It will be appreciated that pharmaceutically acceptable mono or poly alcohols or ethers such as glycols other than propylene glycol may also possibly be used in the barrier film. The particular barrier film coating will depend on the active ingredients present in the pharmaceutical composition of the invention and the mode of administration envisaged. Because atenolol is a drug of low bioavailability, a relatively short time delay is provided by the specific barrier film coating described above to ensure no loss in bioavailability. In the case of other drugs, a more substantial time lag may be possible to accommodate and achieve by modifying the barrier coating. It may be possible to use conventional enteric coatings such as shellac, cellulose acetate phthalate and derivatives thereof, EUDRAGIT™, polymethacrylates and the like.

Claims: A pharmaceutical composition comprising: a first pharmaceutically active ingredient comprising salicylate or a salt, ester, derivative, complex thereof, or salts of the ester, derivative or complex, said first ingredient having anti-platelet activity; a second pharmaceutically active ingredient comprising a β-blocker which interacts with the first ingredient; and a barrier between the first and second active ingredients to substantially prevent interaction therebetween in the composition. A composition as claimed in claim 1 wherein the barrier includes cellulosic material. A composition as claimed in Claim 1 or 2 wherein the barrier includes as a plasticiser a pharmaceutically acceptable alkyl mono or poly alcohol or ether, preferably a glycol, most especially propylene glycol which is compatible with the active ingredients. A composition as claimed in any preceding claim wherein the barrier is provided around the second active ingredient. A composition as claimed in any preceding claim wherein the composition is in a form suitable for oral administration, preferably in the form of a capsule containing the active ingredients and the barrier, most preferably wherein the second active ingredient is in the form of a tablet, the barrier being provided around the tablet and the salicylate surrounds the tablet in the capsule. A composition as claimed in any preceding claim wherein the salicylate is present in a powder or granular form and comprises aspirin or a complex of calcium aspirinate and urea. A composition as claimed in any preceding claim wherein the salicylate comprises aspirin, the second active ingredient comprises atenolol, and the weight ratio of aspirin to atenolol in the composition is from 1:2 to 6:1. A composition as claimed in Claim 8, wherein the ratio of aspirin to atenolol is approximately 3:1. A capsule containing atenolol, aspirin, and a barrier around the atenolol to substantially prevent interaction in the composition between the aspirin and atenolol, the barrier comprising propylene glycol and cellulosic material, and the weight ratio of aspirin to atenolol in the composition being approximately 3:1.

Inventors: BYRNE WILLIAM, CORRIGAN OLIVE, RYNNE ANDREW, BYRNE, WILLIAM, CORRIGAN, OLIVE, RYNNE, ANDREW
Applicants: BYRNE RYNNE HOLDINGS LTD, BYRNE RYNNE HOLDINGS LIMITED
Application year: 1991
Main classification: A61K9
IPC codes: A61K31, A61K9