Pills: break or not break?
Tablet separation is traditionally used in pharmaceutical practice to select the required dose of the drug, if the dosage form with the required dose is not available. It also reduces the cost of therapy. The presence on the tablet of a number of drugs approved by the Food and Drug Administration of the United States (Food and Drug Administration, FDA), the transverse groove is considered to be an approval of this practice and often indicates that the drug has been researched in virto.
However, the tablet separation procedure is not standardized and its accuracy varies considerably depending on a number of factors, including the characteristics of the drug, the size and shape of the tablet, as well as the capabilities and skills of the person who separates him.
It is not recommended to separate the tablets from drugs, the deviations of which can lead to serious consequences. Among these funds are drugs with a narrow therapeutic range and a dose-dependent effect.
The presence of a transverse groove on the tablet facilitates its separation, however, the size, shape and resistance also have a significant impact on the accuracy of the result. Large oblong tablets with deep notches on both sides are more easily separated.
A number of special dosage forms, such as coated tablets for enteric dissolution, delayed release forms of the active ingredient, as well as combined preparations, the concentration of one of the ingredients of which varies depending on the size tablets (for example, amoxicillin / clavulanate (Augmentin, Amoxiclav), irbesartan / hydrochlorothiazide (Avalid), oxycodone / acetaminophen (Percoset), ezetimibe / simvastatin (Vitorin) and others) should not be separated.
As research results have shown, the consistency of drug distribution in the tablet, as well as the likelihood of uniform separation and spalling, is associated with the quality of the preparation. Thus, the presence of large fragments of the active ingredient in generic simvastatin tablets produced in 4 different countries has been revealed, but not in the brand-name drug made in the United States.
The accuracy of tablet separation has been evaluated in a number of studies. In three of them, the pharmacists divided the tablets into 22 drugs; the resulting fragments were considered to contain half the dose if they weighed 85-115% by weight of the ideal half. Weight uniformity requirements were met for 7 of 22 (32%), 3 of 11 (27%) and 8 of 12 (67%) of the drugs tested. In another study, when separating the 10 mg tablets of cyclobenzapine without grooves with a special cutting tool, the weight of the halves varied from 69% to 130% of the expected value, which resulted in dose variations of 3.5 to 6.5 mg provided that the active substance is evenly distributed in a pill. When used to separate a kitchen knife, the variations in half-weight reach 50-150%, the variations in dose from 2.5 to 7.5 mg.
In a study evaluating the capacity of elderly patients to separate the tablets, the weight differences of the halves obtained compared to the expected value reached 9 to 37%.
In two studies, including 2,128 patients taking statins, there was no significant difference in cholesterol concentration in patients who received half the tablets for 6 weeks or more. In another cross-sectional study, 29 patients who received halves of lisinopril tablets for 2 weeks also showed no clinically significant difference in the level of systolic and diastolic blood pressure.
Separation of the tablets reduces the cost of treatment by up to 50% because, under the current pricing policy, many drugs have similar or similar prices per unit dose, regardless of the dose of the active substance in it. When using the Atorvastatin, Simvastatin and Ovastatin tablet separation program, an economic efficiency of 39% was demonstrated during the year.
Of course, using whole tablets allows you to control the dose of medication received by the patient as precisely as possible. Nevertheless, if there is a desire and opportunities on the part of the patient, as well as a wide therapeutic range, the relative safety of the drug and the absence of a dose-dependent effect, the separation of its dosage forms seems possible, because small dose differences are leveled, especially for drugs with a long half-life.
Patients are advised not to separate more than one tablet at the same time and, if possible, to use a soul mate at the next dose to compensate for deviations from the previous dose. The use of special cutting tools can help, but it does not guarantee the precision of the separation.