The Study On Hydroxyapatite As Absorbent

Adding the absorbent may be the best way to ensure that drug tablets areprepared and formed smoothly,when the primary medicine is the essential oil or oilyliquid medicine. The dosage of absorbents is depending on the amount of the oilcontent in the medicine.In general,the dosage of the absorbent is about10%of thetotal amount of the prescription. The capacity of the usual absorbents recorded in thepharmacopoeia is too small, it doesn’t have the effect of absorbent unless the dosageis more than three times of the dosage of oily liquid medicine. There is a greatinfluence on the drugs’ weight. This will increase the pill of drugs that the patientstaking. It is not good for the compliance of patients taking drugs and the developmentof market. Therefore, it is necessary to find out a new kind of absorbent with highcapacity.Hydroxyapatite (HA, HAP, Ca10(PO4)6(OH)2) is the main component of humanand animal teeth and bones,and it is also a porous material. Another characteristic ofhydroxyapatite is its good biocompatibility and high security. Hydroxyapatite has thehigher absorbing character than the usual absorbent,because of the pore ofhydroxyapatite can absorb more oily liquid medicine than those absorbents whichhave no pore. At present,there is no literature reported about the study ofhydroxyapatite on drug absorbent.In this paper, oily liquid vitamin E is used as a model drug drugs to studyhydroxyapatite’s absorption capacity and the influence factors of absorbentperformance. In this paper, vitamin E tablets is prepared by using hydroxyapatite asthe absorbent, and we also study the quality of vitamin E tablets.The experimentalresults show that hydroxyapatite overcome the disadvantage of small capacity of thetraditional absorbent.Its absorbing capacity of vitamin E was3.4times higher thancalcium hydrogen phosphate,2.6times higher than calcium carbonate,and2.47timeshigher than Calcium sulfate. The influence factors of absorbent performance may bethe surface area and the pore volume. When we used hydroxyapatite as vitamin E’sabsorbent,it is smooth and easy to sieve in the granulating process. There is no sticking, laminating and loosing happened in the preparation.The vitamin E tabletshas a smooth surface, uniform color, a high hardness,and no color difference. Thereis a small difference between the weight of vitamin E tablets, which conforms to therequirements of the pharmacopoeia. The content uniformity of the tablets alsoconform to the requirements of pharmacopoeia. Compared to the traditionalabsorbent recorded in pharmacopoeia,such as calcium hydrogen phosphate, calciumcarbonate and calcium sulfate, hydroxyapatite can solve the problem caused by thepresence of oily medicine. These problems include poor convergence,loose particles,poor liquidity, sticking, laminating and loosing, small hardness, high weightdifference,etc. In addition, the study also find that hydroxyapatite can increase thestability of vitamin E tablets. In the accelerated test of the Pharmacopoeia, the shelflife of vitamin E tablets prepared with hydroxyapatite as absorbent is one monthlonger than which prepared with calcium hydrogen phosphate, calcium carbonate orcalcium sulfate as absorbent. While in long-term test of the Pharmacopoeia, the shelflife of vitamin E tablets prepared with hydroxyapatite as absorbent is three monthlonger than which prepared with calcium hydrogen phosphate, calcium carbonate orcalcium sulfate as absorbent.To sum up, hydroxyapatite is expected to become a new pharmaceuticalexcipient.It can be used as absorbent with a high capacity of the essential oil and oilymedicine. It also will be a new member of the absorbents family.This study expandthe application of hydroxyapatite, and increase the practicality of hydroxyapatite.