analgesic

An analgesic (also known as a painkiller) is any member of the diverse group of drugs used to relieve pain (achieve analgesia). The word analgesic derives from Greek an- ("without") and algos ("pain"). Analgesic drugs act in various ways on the peripheral and central nervous systems; they include paracetamol (acetaminophen), the non-steroidal anti-inflammatory drugs (NSAIDs) such as the salicylates, narcotic drugs such as morphine, synthetic drugs with narcotic properties such as tramadol, and various others.

In choosing analgesics, the severity and response to other medication determines the choice of agent; the WHO pain ladder, originally developed in cancer-related pain, is widely applied to find suitable drugs in a stepwise manner.[1] The analgesic choice is also determined by the type of pain: for neuropathic pain, traditional analgesics are less effective, and there is often benefit from classes of drugs that are not normally considered analgesics, such as tricyclic antidepressants and anticonvulsants

Pharmacokinetic advantages of valdecoxib in BCD over valdecoxib

OTHER DRUGS FORMULATED USING BCD

Betacyclodextrin has been used the world over to improve the water solubility of many other drugs. Examples include alprostadil, itraconazole, ziprasidone, dexamethasone, choramphenicol, and NSAIDs such as diclofena, nimesulide, piroxicam and rofecoxib. But for some molecules such as rofecoxib, the improvements in water solubility conferred by BCD have not been substantial. In a bioavailability study conducted to evaluate the benefit of formulating rofecoxib with BCD, investigators used 2 samples of rofecoxib and a sample of rofecoxib in BCD.

IMPROVEMENT IN Cmax

if a drug show high Cmax values, more amount of the drug will be available for distribution to target tissues, thus demonstrating better pharmacotherapeutic action. A study in 12 healthy volunteers compared the peak plasma concentration of valdecoxib alone and valdecoxib in BCD. The study results showed that valdecoxib in BCD achieved higher peak plasma concentrations of valdecoxib in BCD achieved higher peak plasma concentrations (204.82). In this study area under the curve (AUC)for valdecoxib in BCD was higher (1441.71 mcg.h/L)
the above study results prove that valdecoxib in BCD achieves peak plasma concentrations quickle and demonstrates higher peak plasma concentrations and AUC than valdecoxib alone.

IMPROVEMENT IN TMAX

The Tmax of a drug reflects how fast it can reach maximum concentrations in plasma. The faster a drug reaches peak plasma concentration, the faster will the drug show maximum therapeutic action. This is particularly important for drugs that relieve pain.
In crossover study of 12 healthy volunteers comparing the Tmax of valdecoxib in BCD vs valdecoxib alone, valdecoxib in BCD achieved maximum plasma concentration earlier than valdecoxib alone. The investigators found that valdecoxib alone reached peak plasma levels in 2.45 hours shown in figure

VALDECOXIB IN BCD-NOVEL FORMULATION FOR IMPROVED ACTION

As noted, valdecoxib is practically insoluble in water.its solubility can be improved by formulating it with a solubility can be improved by formulating it with a solubility enhancer, BCD. For the first time, this has been achieved by pharmaceutical chemists and formulation is found to be more water soluble than valdecoxib alone. In an in vitro dissolution study,valdecoxib in BCD scored over valdecoxib alone. Valdecoxib in BCD was 100% water soluble in 15 minutes, wheres valdecoxib alone was only 79% soluble in this time. These results have demonstrated positive effects of complexation with BCD on Tmax,Cmax and bioavailability.

BCD

The exterior face of the truncated cone of BCD is hydrophilic this facilitates solubilisation of the complex in the GI fluids by shielding the lipophilic guest molecule from the polar forces of water. Once in the gut lumen, the lipophilic guest molecule dissociates at the lipid membrane of the superficial lining cells. These lipids at the cell interface have greater affinity for the lipophilic guest molecule than does BCD. The librated guest molecule passes into the lining intercellular matrix, lymphatics, and capillaries.