Nystatin is commonly employed to treat fungal infections in the mouth. It is not absorbed via the stomach and it will therefore not treat fungal infections in any part of the body other than the mouth. Nystatin buccoadhesive tablets release the drug very slowly due to the poor solubility of nystatin in water and also the presence of polymers with mucoadhesive properties. Therefore, the aim of the present study was to improve drug release from buccoadhesive tablets, while retaining adequate mucoadhesive properties. To this end, a solid dispersion of nystatin: lactose (1:3) was prepared and mixed with xanthan. The effects of hydrophilic surfactants such as cremophor RH40 and Tween 80 on drug release and mucoadhesive properties of nystatin tablets were also investigated as were swelling and erosion indices and strength of bioadhesion in vitro to a biological membrane. The interaction between nystatin and lactose in solid dispersion formulation was investigated by XRPD, FT-IR and DSC. The results showed that a solid dispersion formulation and mucoadhesive tablets containing surfactants led to faster drug release than their simple physical mixtures. Drug release was also faster from a solid dispersion compared to tablets containing surfactants. Swelling and erosion results showed that tablets made of a solid dispersion swelled and eroded faster than a physical mixture formulation. The presence of surfactant slightly increased the degree of swelling and erosion of buccoadhesive tablets.

The potential of the polyampholytic and polyelectrolytic starch compounds as excipients for drug controlled release was investigated using various tracers differing in terms of solubility and permeability. Ampholytic trimethylaminecarboxymethylstarch (TMACMS) simultaneously carrying trimethylaminehydroxypropyl (TMA) cationic groups and carboxymethyl (CM) anionic groups was obtained in one-step synthesis in aqueous media. Trimethylaminestarch (TMAS) and carboxymethylstarch (CMS) powders were also synthesized separately and then homogenized at equal proportions in liquid phase for co-processing by spray drying (SD) to obtain polyelectrolytic complexes TMAS-CMS (SD). Similarly, equal amounts of TMAS and CMS powders were dry mixed (DM) to obtain TMAS:CMS (DM). Monolithic tablets were obtained by direct compression of excipient/API mixes with 60% or 80% drug loads. The in vitro dissolution tests showed that ampholytic (TMACMS) and co-processed TMAS-CMS (SD) with selected tracers (one from each class of Biopharmaceutical Classification System (BCS)), were able to control the release even at very high loading (80%). The presence of opposite charges located at adequate distances may impact the polymeric chain organisation, their self-assembling, and implicitly the control of drug release. In conclusion, irrespective of preparation procedure, ampholytic and polyelectrolytic starch materials exhibited similar behaviours. Electrostatic interactions generated polymeric matrices conferring good mechanical features of tablets even at high drug loading.

The prepared waxy matrix tablet containing NC complexes with CD shows promising results as extended release tablets.

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Different starch derivatives were evaluated as supports for attachment and recovery of macrophages (RAW 264.7 line). Gelatinized starch (G-St), acetate starch (Ac-St), carboxymethyl starch and aminoethyl starch were synthesized and characterized by FTIR, H NMR, SEM and static water contact angle. These polymers are filmogenic and may coat well the holder devices used for macrophage adhesion. They also present a susceptibility to mild hydrolysis with alpha-amylase, liberating the adhered macrophages. Cell counts, percentage of dead cells and level of tumor necrosis factor (TNF-α) were used to evaluate the possible interaction between macrophages and starch films. The high percentage of cell adhesion (90-95% on G-St and on Ac-St) associated with enzymatic detachment of macrophages from film-coated inserts, resulted in higher viabilities compared with those obtained with cells detached by current methods scrapping or vortex. This novel method allows a fast macrophage separation, with excellent yields and high viability of recovered cells.