Google Scholar. Firsova and K. Tarantseva, M. Marynova, and M. Rossii , 9 , 12—15 Tarantseva, N. Firsova, and O. Download references. You can also search for this author in PubMed Google Scholar. Correspondence to K. Reprints and Permissions. Tarantseva, K. Chem Petrol Eng 51, — Download citation.
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Skip to main content. The composition optionally also contains one or more of a water soluble or water dispersible diluent. The quantities of the hydrophilic polymers and water soluble or water dispersible diluent are such that the therapeutically effective active ingredient is released at a rate suitable for twice daily administration of the pharmaceutical composition to human subjects.
The tablets may also be coated with a rapidly dissolving water soluble polymeric film coat. FIELD OF THE INVENTION This invention relates to a pharmaceutical composition of modified release tablets comprising cefaclor or cephalexin, or their pharmaceutically acceptable hydrates, salts, or esters as active ingredient, and a mixture of hydrophilic polymers of different viscosity grades selected from the group consisting of at least one hydroxypropyl methylcellulose and at least one hydroxypropylcellulose.
Optionally, the tablets may be coated with a rapidly dissolving water soluble polymer film coat. The use of hydrophilic polymers to produce sustained or modified release pharmaceutical compositions is known in the art.
For modified release solid dosage forms comprising a drug dispersed uniformly in hydrophilic polymers, release of the drug is controlled primarily by diffusion of the drug, or by surface erosion of the hydrophilic polymers into the surrounding medium, or by a combination of the two processes.
Control of the rate of release benefits therapy by producing constant blood levels of the active ingredient and by decreasing the frequency of administration, thereby improving patient compliance to the dosage regimen.
The present invention provides a pharmaceutical composition of modified release tablets of cefaclor or cephalexin suitable for twice-daily administration to human subjects. Several controlled drug delivery system adapted for the delivery of cefaclor or cephalexin are known in the prior art. Although a specific cefaclor formulation is described, the description in the patent suggests that the formulation is suitable for any drug and is particularly suitable for cephalexin and cefaclor.
A coating of a slowly soluble water permeable ethylcellulose polymer surrounds the core matrix. The coated portion is coated with a copolymer of methylmethacrylate and methacrylic acid which dissolves at a pH of from 5. The potency ratio of the normal cephalexin to the coated portion is between and The coating comprises a film-forming forming polymer which is insoluble in water and gastrointestinal fluids and consists essentially of a terpolymer of polyvinylchloride, polyvinyl acetate and polyvinyl alcohol, and a water soluble pore creating material randomly distributed in the terpolymer coating.
The pore creating substance is present in an amount of one part to 35 parts for each one to ten parts of terpolymer. Cephalexin is one of the active ingredients disclosed. At least one of the inner layers comprises an active medicament, which has a solubility which varies with pH and is either basic or acidic, and at least one pH adjuster. The pH adjuster is an organic acid or organic acid salt if the medicament is basic, or an inorganic base or basic salt if the medicament is acidic.
The pH adjuster is present in an amount sufficient to ensure that the rate of dissolution of the medicament is substantially independent of the pH of the environment in which dissolution occurs. Cephalexin is described as one of the possible medicaments. The tablets may be coated with a rapidly dissolving water soluble film coating. The tablet may be optionally coated with a rapidly dissolving water soluble polymer film coat.
According to the present invention the pharmaceutical composition contains cefaclor or cephalexin, or their pharmaceutically acceptable hydrates, salts or esters as active ingredient. Further, the cefaclor or cephalexin or their pharmaceutically acceptable hydrates, salts, or esters may be present in an amount from mg to mg per tablet.
According to the present invention, the pharmaceutical composition contains a mixture of hydrophilic polymers of different viscosity grades selected from the group consisting of hydroxypropyl methylcellulose and hydroxypropylcellulose. The hydroxypropyl methylcellulose polymers may be present in the pharmaceutical composition of the present invention in an amount from about 0. The hydroxypropylcellulose polymers may be present in an amount from about 0.
Examples of water soluble diluents that may be used in the present invention include, but are not limited to, lactose, calcium sulfate, mannitol, dextrates, dextrin, dextrose, sucrose and the like. Water dispersible diluents refer to water insoluble pharmaceutical excipients which disperse readily in water.
Examples of water dispersible diluents that may be used in the present invention include, but are not limited to, cellulose based diluents such as microcrystalline cellulose and powdered cellulose; various starches such as corn starch and pregelatinized starch; clays or clay minerals such as kaolin, bentonite, attapulgite, and the like. The advantage of the above mentioned process of the present invention is that it is free of any disadvantages associated with granulation by aqueous or non-aqueous vehicles used conventionally.
The drugs cefaclor and cephalexin, which are sensitive to moisture and heat, can be effectively processed without any difficulty by the process of the present invention. In the pharmaceutical industry, particularly, much emphasis is directed to limit the residual solvents for the safety of the patients and such problems of residual organic solvents are eliminated by the process of the invention.
The tablets may be optionally coated with a rapidly dissolving water soluble film coat. Preferably, the coating composition contains a flavoring agent in order to mask the taste and odor of the active ingredient. The modified release matrix formulation prepared according to the present invention is not a mere admixture but has properties different from the sum total of the properties of its ingredients. This example illustrates the preparation of controlled release tablets of cefaclor having a composition as given in Table 1.
Cefaclor, the hydrophilic polymers and lactose were screened through a fine sieve and mixed with half of the magnesium stearate and talc.
The mixture obtained was compacted and then milled. The sized granules were blended with the fines and the remaining lubricants followed by compression into tablets.
The percent build-up was 2. The coated tablets were tested for dissolution in ml of 0. The dissolution medium pH 6. Spectrophotometric methodology at nm was used for estimation of drug release. The results are given in Table This example illustrates the preparation of controlled release tablets of cefaclor having a composition as given in Table 4. The cefaclor, hydrophilic polymers, lactose and the lubricants were mixed together and the blend so obtained was compressed into tablets.
The tablets were tested for dissolution as described in Example 1.
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