skin penetration

The aim of present study was to design and development of a proniosomal transdermal drug delivery system of lornoxicam for the treatment of rheumatoid arthritis and enhanced skin targeting effect, sustained & prolonged drug release, enhanced skin bioavailability by using different type of non ionic surfactant & cholesterol. Proniosomes of Lornoxicam were prepared by coacervation-phase separation method. The formulation systems were characterized in vitro for size, vesicle count, drug entrapment, drug release profile and vesicular stability. The method used for preparing proniosome resulted in an encapsulation yield of 67.71-87.64%. Proniosomes were characterized by transmission electron microscopy. In vitro studies showed prolonged release of entrapped lornoxicam. A successful attempt was made to develop proniosomal gel for transdermal delivery of lornoxicam using different grades of nonionic surfactant.

The proniosomal approach helps to solve the problem regarding stability and provides higher entrapment efficiency over conventional system. Proniosomal gel is a liquid crystalline- compact niosomal hybrid which is prepared by dissolving surfactant in small amount of suitable solvent and least amount of aqueous phase. This compact gel can be converted to niosomes hydration. Proniosomes can entrap hydrophilic as well as lipophillic drugs. Proniosomal gel offers a versatile vesicle drug delivery concept with potential for drug delivery via transdermal rout. Over the last few years an inclusive research has been done over pro-vesicular approach for transdermal drug delivery. Skin has a very tough diffusion barrier inhibiting penetration of drug moiety which is rate limiting barrier for penetration of drugs. There are several approaches that deal with penetration enhancement across the skin. Vesicular and provesicular systems are promising amongst them. Vesicular systems including (niosomes, ethosomes, transfersomes and liposomes) are promising systems to cross this permeation barrier.

Over the last few years an inclusive research has been done over provesicular approach for transdermal drug delivery. Skin has a very tough diffusion barrier inhibiting penetration of drug moiety which is rate limiting barrier for penetration of drugs. There are several approaches that deal with penetration enhancement across the skin. Vesicular and provesicular systems are promising amongst them. Vesicular systems including (niosomes, ethosomes, transfersomes and liposomes) are promising systems to cross this permeation barrier. The proniosomal approach helps to solve the problem regarding stability and provides higher entrapment efficiency over conventional system. Proniosomal gel is a liquid crystalline- compact niosomal hybrid which is prepared by dissolving surfactant in small amount of suitable solvent and least amount of aqueous phase. This compact gel can be converted to niosomes hydration. Proniosomes can entrap hydrophilic as well as lipophillic drugs. Proniosomal gel offers a versatile vesicle drug delivery concept with potential for drug delivery via transdermal rout.

  The conventional oral dosage forms has significant drawbacks of low bioavailability due to hepatic first pass metabolism and tendency to produce rapid blood level spikes (Both high and low), leading to a need for frequent dosing, which can be both cost ineffective and inconvenient. To improve such characters transdermal drug delivery system (TDDS) was emerged which will improve the therapeutic efficacy and safety of drugs by more precise (i.e. site specific) placement within the body thereby reducing both the size and number of doses. The TDDS has numerous advantages over the more traditional drug delivery system. These include high bioavailability, absence of first pass hepatic metabolism, maintenance of steady plasma level of the drug, increase therapeutic efficiency. This review article provides an overview of TDDS, its advantages over conventional dosage forms, Limitations, various components of Transdermal patches, types of Transdermal patches, methods of preparation and Ideal requirements for TDDS, regulatory issues over transdermal drug delivery and its physicochemical methods of evaluation. Key words: Transdermal drug delivery systems, Transdermal patches, skin penetration, Topical drug delivery