Formulation of a Niosomal Gel Containing Chamomile Hydro alcoholic Extract with Analgesic Effect by Film Hydration Method

Introduction: Pharmacological studies revealed anti-inflammatory and analgesic properties of chamomile and its main components. The aim of the present study is preparing and characterizing a niosomal gel containing chamomile extract. Methods: Nisomes containing 2% and 5% of the extract were prepared using film hydration method. Non-ionic surfactants including sorbitan esters (spans) and ethoxylated sorbitan esters (tweens) as well as cholesterol were used. Physicochemical evaluations of the niosomes including microscopic characteristics, stability studies, and encapsulation efficacy and in-vitro release test were performed. The rheological behavior of the niosomal gel was also evaluated. Results: Morphology studies indicated the formation of MLV and LUV niosomic vesicles. The stability test results show span 60/tween 60 formulations in both 2% and 5% of the extract met the stability criteria. HPLC analysis revealed that encapsulation efficacy of the formulation containing 60% Span 60/Tween 60, 40% cholesterol and 5% extract was 64%. The release test results show a 30% release of apigenin (standard) from the formulation. Rheological study on the niosomal gel revealed a pseudo-elastic behavior. Conclusions: Niosomes containing span 60/tween 60, 40% cholesterol and 5% chamomile extract showed the most acceptable physiochemical characteristics and is recommended to be used in further pharmacological and clinical investigations.