Acetaminophen tablets solubility determination experiment
Summary
Dissolution degree refers to the speed and degree of dissolution of drugs from solid preparations such as tablets or capsules in the specified solvent. However, in practice, the degree of dissolution only refers to the degree of dissolution of the drug within a certain period of time, used to (1) determine the degree of dissolution of the drug tablets (2) the quality of the tablets and the effect of judgment.
Operation method
turn basket method (math.)
Principle
When taken, solid preparations such as tablets undergo two processes in the gastrointestinal tract, disintegration and dissolution, before they can be absorbed through biofilms. For many drugs, the amount absorbed is usually proportional to the amount of the drug dissolved from the dosage form. For insoluble drugs, dissolution is the main process, so the disintegration time frame is often not an indicator of the degree of absorption of insoluble drug formulations. Solubility less than 0.1 ~ 1.0 (g / L) of the drug, in vivo absorption is often affected by its dissolution rate. Dissolution rate in addition to the crystalline form of the drug, particle size, but also with the preparation of the production process, excipients, storage conditions and so on. In order to effectively control the quality of solid preparations, in addition to the use of blood concentration method or urine concentration method and other in vivo measurements to estimate the rate of absorption, in vitro dissolution assay is a simpler method of quality control. Dissolution refers to the speed and degree of dissolution of drugs from tablets or capsules and other solid preparations in the specified solvent. However, in practical application, the degree of dissolution only refers to the degree of drug dissolution within a certain period of time, generally expressed as a percentage of the labeled amount, such as the Pharmacopoeia stipulates that the dissolution limit of acetaminophen within 30 minutes is 80% of the labeled amount. For oral solid preparations, especially for which in vivo absorption of insoluble solid preparations, as well as the therapeutic dose and toxic dose of drugs close to the solid preparations, should be made to check the degree of dissolution and as a quality standard.
Materials and Instruments
Acetaminophen Tablets Dissolve Move I. Instrumentation for the turn-basket method Caveat 1. Dissolution instrument water bath box should be added to the water line of purified water, water should be circulated after power on. 2. solution filtration with no more than 0.8 um microporous membrane filtration, from sampling to filtration should be completed within 30 seconds. For more product details, please visit Aladdin Scientific website.
Hydrochloric acid Water Sodium hydroxide
Rotary basket Beaker Spectrophotometer
1. The basket is divided into basket body and basket shaft two parts, are made of stainless steel metal materials. Stainless steel wire mesh inner diameter of 22.2 mm ± 1.0 mm, turn the basket rotation amplitude shall not exceed ± 1.0 mm.
2. 1,000 ml of round-bottomed beakers for the operating container, jacket water bath; water bath temperature should be able to make the container temperature of the solvent to maintain at 37 ℃ ± 0.5 ℃. The distance between the bottom of the rotating basket and the bottom of the beaker is 25 mm ± 2 mm.
3. The electric motor is connected to the basket shaft, and the rotational speed can be arbitrarily adjusted at 50 to 200 revolutions per minute, and the error of the steady speed does not exceed ± 4%.
4. The instrument should be equipped with 6 sets of operating devices, can be measured at a time 6 copies of the test material. The location of the sampling point should be turned to the upper end of the basket from the middle of the liquid surface, away from the beaker wall 10 mm.
II. Determination of dissolution degree of acetaminophen tablets
1. 24 ml of dilute hydrochloric acid plus degassed water to 1,000 ml of solvent, measure 1,000 ml of solvent into each operating container, and heat the solvent to maintain the temperature at 37±0.5℃. The rotary basket speed was adjusted to 100 revolutions per minute and allowed to stabilize.
2. Take 6 slices of the test article and put them into each of the 6 rotary baskets, lower the rotary baskets into the containers and start the timer immediately. After 30 minutes, take 5 ml of the solution, filtered, precision measurement of the filtrate 1 ml, add 0.04% sodium hydroxide solution diluted to 50 ml, shaking, according to the spectrophotometric method, at 257 nm wavelength to determine the absorbance, according to the absorption fraction of C8H9NO2 (E1%1 cm) is 715 calculated as the amount of dissolution of each tablet. The limit is 80% of the labeled amount, which should be in accordance with the regulations.
Third, the results of judgment
The dissolved amount of each of the 6 tablets, calculated according to the labeled content, should be not less than the specified limit (Q); unless otherwise specified, the limit (Q) is 70% of the labeled content. If only 1 of the 6 tablets is lower than the specified limit, but not lower than Q ~ 10%, and the average dissolved amount is not lower than the specified limit, it can still be judged as compliant. If 1 of the 6 slices is lower than Q ~ 10%, another 6 slices should be taken for retesting; only 2 of the 12 slices in the initial and retesting are lower than Q ~ 10%, and the average dissolved amount is not lower than the prescribed limit, it can also be judged as conforming to the regulations.