The Effects of Excipients on Pharmaceutical Preparations

Excipients are very important for pharmaceutical preparations. It can be said that without excipients, there will be no pharmaceutical preparations, let alone different pharmaceutical dosage forms such as powders, granules, tablets, oral liquids or injections. When the drug and the appropriate excipients are combined into a specific dosage form, the drug would become safer, more stable and more convenient to use. Divided doses are easier to be accepted by the body.

However, in addition to the above-mentioned effects, excipients of the drug are also one of the important factors that determine the effect of the preparation and how safe it is. What impacts will different excipients exert on the quality of pharmaceutical preparations?

First, let us look at the excipients used in the production of dextran and?-cyclodextrin oligomers. This type of pharmaceutical preparations have a common feature, that is, after oral absorption, the drug will enter the body's circulation. By using specific pharmaceutical technology, dextran and certain drugs can be combined through dextran covalent bonding, which have stronger lymphatic circulation tropism than those made with excipients of other ingredients. This is to say that relatively more drugs will enter the lymphatic circulation and at the same time avoid the first pass effect of the drug in the liver.

In this way, it not only greatly reduces the damage of the drug to the liver, but also greatly reduces the chance of the drug being partially inactivated by the liver. Therefore, a lot of benefits are there after the pharmaceutical preparation of this excipient is used in animals, including improved safety, less toxicity and fewer side effects. In addition, because more drugs can reach the target site, the drug effective time has been extended, and the clinical effect is better.

Secondly, some excipients’ chemical properties are relatively active. To use such excipients, researchers must carefully control their amount, otherwise it will greatly reduce the safety of the clinical application of pharmaceutical preparations. For example, using a large amount of sweetener excipients such as sucrose is likely to cause dental caries. When a large dose of sorbitol is used as an excipient for pharmaceutical preparations, it will cause adverse reactions such as diarrhea and bloating in animals. Through its aldehyde group, lactose undergoes a condensation reaction with those drugs with primary and secondary amine structures, thereby reducing the content of the active ingredients of the main drug, resulting in unsatisfactory or ineffective drug treatment.

In addition, experts have found that tetracyclines are susceptible to cations such as calcium, magnesium, zinc, iron, and form poorly soluble or insoluble complexes, thereby greatly reducing the effect of tetracycline pharmaceutical preparations. Drug manufacturers should avoid using some metal salts as excipients when developing and producing such preparations. It is necessary to add some specific chelating agents to improve the performance of such pharmaceutical preparations.

Finally, for those crystalline drugs, the more advanced excipient technology used in drug formulation development, the better effect of the product is. In the study of drug crystalline form, the commonly used substances that form co-crystals with the active ingredient (API) are mainly solvents, acids or bases (co-crystals can also be formed during salt formation), or other small molecules. Finding "advantageous drug crystal form" has become the focus of current drug crystal form research. For example, ofloxacin is a crystalline drug with different configurations. Among the many configurations, levofloxacin is the most active and the dominant configuration.

The author has been engaged with pharmaceutical preparation for years and has accumulated experience in excipients and drug formulation.