Development and mechanical characterization of solvent-cast polymeric films as potential drug delivery systems to mucosal surfaces

Abstract

Solvent-cast films from three polymers, carboxymethylcellulose (CMC), sodium alginate (SA), and xanthan gum, were prepared by drying the polymeric gels in air. Three methods, (a) passive hydration, (b) vortex hydration with heating, and (c) cold hydration, were investigated to determine the most effective means of preparing gels for each of the three polymers. Different drying conditions [relative humidity - RH (6-52%) and temperature (3-45 degrees C)] were investigated to determine the effect of drying rate on the films prepared by drying the polymeric gels. The tensile properties of the CMC films were determined by stretching dumbbell-shaped films to breaking point, using a Texture Analyser. Glycerol was used as a plasticizer, and its effects on the drying rate, physical appearance, and tensile properties of the resulting films were investigated. Vortex hydration with heating was the method of choice for preparing gels of SA and CMC, and cold hydration for xanthan gels. Drying rates increased with low glycerol content, high temperature, and low relative humidity. The residual water content of the films increased with increasing glycerol content and high relative humidity and decreased at higher temperatures. Generally, temperature affected the drying rate to a greater extent than relative humidity. Glycerol significantly affected the toughness (increased) and rigidity (decreased) of CMC films. CMC films prepared at 45 degrees C and 6% RH produced suitable films at the fastest rate while films containing equal quantities of glycerol and CMC possessed an ideal balance between flexibility and rigidity.

Lyophilized wafers comprising carrageenan and pluronic acid for buccal drug delivery using model soluble and insoluble drugs

“…Where Qt is the amount of drug released in time t, Q ∞ is the initial amount of drug present in the film, k is a constant comprising the structural and geometric characteristics of the formulation and n is the release exponent [22,23]. As shown in Table 2, the R 2 values determined were 0.99 and 0.96 for IBU and PM wafers respectively.…”

Formulation, Characterisation and Stabilisation of Buccal Films for Paediatric Drug Delivery of Omeprazole

“…On the other hand soft and strong polymers display acceptable strength, low elastic modulus and high percent elongation at break [17]. The films showed significant differences in the tensile strength (brittleness) based on the PEG concentration.…”

“…The removal of the air bubbles entrapped inside the gel was essential to avoid any empty gaps, which could lead to non-uniform distribution of various film components. The drying process for unplasticised gels was shorter (12 h) compared to plasticised gels (18-24 h) due to the known water affinity of most plasticisers [17].…”

“…The percent elongation at break point of MET gradually increased with increased concentration of PEG. It has been suggested that the average percent elongation at break point should ideally be between 30 and 50% [17] which indicates a good balance between flexibility and elasticity. MET films prepared from gels containing 0.5 and 0.75% w/w of PEG satisfied this criteria.…”

Polysaccharide Based Formulations for Mucosal Drug Delivery: A Review

“…The size of the delivery system varies with the type of formulation, for example, a buccal tablet may be approximately 5-8mm in diameter, whereas a flexible buccal patch may be as large as 10-15cm 2 in area. The thickness of the delivery device is usually restricted to below 1 mm [14,107]. Different types of buccal formulations such as; tablets, patches and films, semisolids and powders are used depending upon the desirable pharmacological action [108].…”