RESUMEN
Buccal tablets
Diclofenac sodium
Drug release
Mucoadhesion
Mucoadhesive tablets
Release kinetics
RESUMEN
Abstract Hydralazine hydrochloride is an anti-hypertensive drug. The drug has poor oral bioavailability (BA) of about 30- 50% due to extensive first-pass metabolism. Hence, the buccal delivery was used to enhance the BA of hydralazine hydrochloride. Buccal muco-adhesive tablets were prepared by direct compression technique, using carbopol 934P, HPMC K4M, sodium alginate and sodium carboxy methyl cellulose (NaCMC) as muco-adhesive polymers. Prepared formulations were evaluated for physico-chemical characterization, ex-vivo residence time and in-vitro release studies. The some of the parameters viz hardness, thickness, weight variation are showing the values within the pharmacopeial limits. However, the swelling and bio-adhesive strength were increased with increasing polymer concentrations. From the in-vitro release studies, F9 buccal tablets prepared with NaCMC exhibited better release (96.56%, 6 h) profile than all other formulations and considerd as optimized. The release mechanism from kinetic methods suggests that, the drug release follows zero-order kinetics with diffusion mechanism. Thus, the buccal tablets of hydralazine hydrochloride showed enhanced BA and were further confirmed by in-vivo studies.
RESUMEN
Delivery of drugs through the skin has been always a challenging area for research due to barrier properties exhibit by the outermost layer of skin stratum corneum. In the last two decades, the transdermal drug delivery system has become a proven technology that offers significant clinical benefits over other dosage forms. Because transdermal drug delivery offers controlled as well as predetermined rate of release of the drug into the patient, it able to maintain steady state blood concentration. It’s a desirable form of drug delivery because of the obvious advantages e.g.convenient and pain-free self-administration for patients, avoidance of hepatic first-pass metabolism and the GI tract for poorly bioavailable drugs over other routes of delivery. The outlook for continued growth of the TDD market is very optimistic.Transdermal drug delivery has made an important contribution to medical practice, but has yet to fully achieve its potential as an alternative to oral delivery and hypodermic injections. This review emphasizes the three generations of transdermal drug delivery which start a new era of delivery of drug.
RESUMEN
OBJECTIVE: Available information on the background of the current state and advances of the intestinal lymph trans port of medicines were reviewed. Drug transported by the intestinal lymphatic system can avoid hepatic first-pass metabolism, increase the bioavalibitlty of the highly lipophilic drug, and it is of importance for immunomodulatory, anticancer and anti-infective drugs. METHODS: We conducted a systematic literature review of articles published recent years, analysis and summaries are made upon the advances and methods applied for the increase of the intestinal lymph transport. RESULTS AND CONCLUSION: Intestinal lymphatic transport can increase the bioavailability via a reduction in the first-pass metabolism and the possibility of specifically targeting drugs to regions of the lymphatics, thus it is very advantageous for drugs that are under significant first-pass metabolism. The present review embodies a brief background of the mechanism of access of drugs to the intestinal lymph, a discussion on the links between lipid absorption and transport of highly lipophilic drugs, and approaches for enhancing lymphatic drug transport. Finally, experimental models of the lymphatic transport are also discussed.
RESUMEN
The uptake of oral administered drugs primarily occurs in the small intestine,which also has the capability to metabolize drugs.Both phase Ⅰ and phase Ⅱ metabolic enzymes were expressed in the intestinal mucosa,and cytochromes P450(CYP450s) are the principle enzymes attributed to the biotransformation of drugs.CYP3A and CYP2C are the most abundant subfamilies,accounting for approximately 80% and 16% of total CYP450s in the intestine.Compared to the liver,the expression and activity of CYP450 enzymes in the intestine was susceptible to inducers or inhibitors,leading to drug-drug interaction.This article reviews the expression of CYP enzymes in small intestine and the role of the gut wall in CYP-mediated xenobiotic metabolism.Possible drug-drug interactions due to induction or inhibition of CYP enzymes in the small intestine are also addressed.
RESUMEN
Intestinal CYP3A4-mediated biotransformation and active efflux of absorbed drug by P-glycoprotein are major determinants of bioavailability of orally administered drugs. The expression of CYP3A4 and P-glycoprotein in the intestine is not co-ordinately regulated. However, synergistic actions of CYP3A4 and P-glycoprotein in intestinal drug disposition have been confirmed by in vitro and animal studies. Further understanding of this interaction would be potentially useful to improve oral bioavailability of CYP3A4/P-glycoprotein substrates.