Development of in situ poloxamer-chitosan hydrogels for vaginal drug delivery of benzydamine hydrochloride: Textural, mucoadhesive and in vitro release properties

Abstract

The use of in situ hydrogel systems for vaginal drug delivery is an important strategy in the treatment of vaginitis. The aim of this study was to develop in situ vaginal hyrogels for benzydamine hydrochloride (BNZ) which were composed of poloxamer and chitosan. The reason for development of these hydrogels was to obtain a vaginal delivery system with improved mechanical and mucoadhesive properties that could provide prolonged retention time for the treatment of vaginits. The hydrogels were also designed for once a day dosage of the drug and to obtain a controlled release of the BNZ. For this purpose BNZ containing hydrogel formulations using thermosensitive polymer (Poloxamer 407) and mucoadhesive polymer (Chitosan H, Chitosan M and Chitosan L) were developed. The hydrogels are composed of polymers which have promising potential for vaginal delivery systems. These formulations were evaluated by rheology, texture, mucoadhesive profiles and drug diffusion with a Franz diffusion cell. It was observed that the diffusion of BNZ from the in situ poloxamer-chitosan hydrogel was more sustained and controlled than with the poloxamer gel. The hydrogel formulations diffused about 65.3±5.1, 80.6±3.8, 88.1±7.3 and 100.4±4.8% of BNZ at 6h. The formulation containing Poloxamer 407 and Chitosan H has the best controlled release profile and mucoadhesive properties, results which indicate that it could suitable for use once a day on the vaginal route. Moreover, the hydrogels higher mucoadhesion exhibited by this formulation prolongs the drug residence time compared with the poloxamer gel and may increase the BNZ efficacy. These BNZ mucoadhesive vaginal hydrogel formulations may be a promising alternative to conventional dosage forms for vaginal topical therapy.Key words: Mucoadhesion; poloxamer; chitosan; hydrogel; benzydamine hydrochloride; vaginal drug delivery. INTRODUCTIONThe vagina is the site of various pathologies such as vaginitis caused by bacteria, fungi, protozoa or virus and has been traditionally employed for the delivery of several drugs. Lately, the vagina has been utilized as a possible alternative to the parenteral administration route for the delivery of drugs [1]. Vaginal dosage forms have been developed for many drugs because of the vagina presents several advantages as a site for drug delivery, such as having large surface area, rich blood supply, avoidance of the first-pass effect, relatively high permeability to several drugs, and self-insertion [2]. It should also allow self-administration with minimal interference on body functioning and daily life, and obtain high bioavailability with other medications. The rate and extent of drug absorption after intravaginal administration may vary, depending on formulation factors, vaginal physiology, age of the patient and menstrual cycle. Suppositories, creams, gels, tablets and vaginal rings are commonly used as vaginal [3]. Gel formulations are frequently preferred for the vaginal application of various drugs with different effects, such as moisturizing ...

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