| Prostaglandin Ei(PGEi), also named alprostadil, is an important naturally occurring biological active substance of human body. There are many physiological and pharmacological functions of PGEi such as relaxing vascular smooth muscles, inducing vasodilatation of coronary artery and periphery vessels, inhibiting platelet agglutination, improving peripheral circulation and adjusting activity of inflammation cells etc. It is used clinically to treat periphery vessel disease, erection dysfunction(ED), cerebral artery hypertension, ischemic heart disease and hyperlipidemia. It is also used as assistant therapy method in treating hepatitis, diabetes, peptic ulcer, renal failure and pancreatitis. PGEi has the characteristic of low dosage, remarkable curative effects and fewer side effects. But the unstable physicochemical properties, poor solubility in water, severe degradation in gastrointestinal tract and ineffectiveness take orally which made the pharmacy research more difficult. Now the dosage forms in market are dry powder, emulsion for injection and cream, jellies, urethral suppository for external use. The injection preparations often induce obvious vascular irritation, which bring patients pains. The external dosage forms in domestic market are cream and urethral suppository. Both of them are used in therapy of erection dysfunction(ED).The research found the optimal menstrua system by modern pharmacy technologies. The system successfully solved the problems of chemical stability and solubility of PGEi. The screening penetration test in vitro help us to find the most active enhancer, which cause 5.01-fold cumulative amount and 5.2-fold Kp increase contrast to basic formulation. At last, the formulation was determined through systematic evaluation. The following studies proved that the PGEi transdermal delivery system was safe, effective and quality- controllable.A stability study method of PGEi was developed. The stability study on transdermal delivery system including factors test, accelerating test and long-term testindicated that the dosage form was stable, nearly without any changes during the stability study.In the studies of irritation on rabbit skins and allergic response on Guinea pig skins showed neither reversible inflammations nor immune passing reaction. They proved that the form wouldn't induce irritation and sensitization. It was well biological consistent and able to use in long-term.Because of the minim administration dose (100fig per time), the fast metabolize course (ti/2was 0.54 min), the high plasma protein binding rate (nearly 93%) and the sensitivity of determination constrained the feasibility of pharmacokinetics study in vivo. So we established in situ perfused rabbit ear model for percutaneous absorption to evaluate the penetration abilily of PGEi transdermal delivery system on live skins. The results showed the forms had good permeation.The particular formulation of PGEi transdermal delivery system not only solved the solved the problems of chemical stability and solubility, but also showed high penetration rate and bioavailability. It was safe and convenient. The study provide a theory basis for developing new dosage form of PGEi in future. The PGEi transdermal delivery system had been reported previously. The application of China Patents will be performed.
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