Formulation and evaluation of mucoadhesive glipizide films

Development and optimization of a new tioconazole vaginal mucoadhesive film using an experimental design strategy. Physicochemical and biological characterization

A new tioconazole (TCZ) mucoadhesive film, based on a biodegradable chitosan/ hydroxypropyl methylcellulose (CH/HPMC) blend, was developed for treatment of vaginal candidiasis. The formulation was optimized through an I-optimal design (minimizing the integral of the prediction variance across the factor space), where the impact of the proportion of the ingredients and processing variables on the quality of the final product was evaluated. Both, the thickness of the film and the swelling index, which affect patients' comfort and compliance, were considered. Mechanical testing, such as load at break, elongation at break, and mucoadhesive strength were also included as dependent variables. The optimal mucoadhesive film formulation, which should be obtained at a drying temperature of 30 °C, was found to include the combination of CH and HPMC (forming polymers) at 0.25:0.75 ratio, a mixture of polyethylene glycol 400 and propylene glycol as plasticizers (0.07:0.93, 5% w/w), and TCZ loaded at 15 % w/w. The optimal preparation was subjected to exhaustive characterization studies, which revealed that the drug was entrapped in the polymeric matrix in an amorphous state and that the film exhibited a smooth and uniform surface, demonstrating excellent component compatibility. In vitro tests showed that the formulation has an excellent time to kill value (3 min) and lacks cytotoxicity, suggesting that it should be highly effective and safe.

Novel Swellable/Expandable Gastroretentive Floating Films of Gliclazide Folded in Capsule Shell for the Effective Management of Diabetes Mellitus: Formulation Development, Optimization and In Vitro Evaluation

Background:

Gliclazide (GLZ) belongs to the second-generation of sulphonylureas; it is a drug of choice for the management of type II DM. It belongs to BCS Class II. The major site of drug absorption for GLZ is the stomach; it displays variation in the drug absorption rate and bioavailability due to the shorter gastric retention time. The floating mechanism gets affected when the gastric fluid level is not sufficiently higher, which ultimately obstructs the floating behavior, which is the major limitation of reported formulations. This limitation can be overcome by folding the film into the capsule shell dissolved in the gastric fluid and the film swells/expands to dimensions higher than pylorus sphincter (12mm), thus preventing its evacuation.

Objective:

The study aims to explore the floating mechanism in the design of films along with a tendency to expand by swelling and unfolding by utilizing a mixture of hydrophilic and hydrophobic polymer to achieve the controlled drug delivery and prolonged gastric retention of drug.

Methods:

The gastroretentive floating films were formulated by the solvent casting technique using 32 full factorial designs and subjected to in vitro evaluation parameters, drug-excipient compatibility, Xray diffraction and accelerated stability study.

Results:

The pre-formulation study established the purity and identification of a drug. FTIR study confirmed no drug excipient interaction. F3, F6, and F9 were optimized based on in vitro floating characteristics, swelling/expanding ability, and unfolding time. All developed formulations were unfolded within 14-22 min after capsule disintegration. The F3 was selected as the final formulation as its ability to control the release of the drug for 24 hrs followed by zero-order kinetics having super case 2 transport. XRD confirmed the amorphousness of the drug within the formulation. The stability study results revealed that the formulation was quite stable at extreme storage conditions.

Conclusion:

The developed novel formulation has good potential for the effective management and treatment of diabetes mellitus.

Enhanced gastrointestinal survivability of recombinant Lactococcus lactis using a double coated mucoadhesive film approach

Vaccine administration via the oral route is preferable to parenteral routes due to ease of administration. To date, most available oral vaccines comprises of live attenuated pathogens as oppose to peptide-based vaccines due to its low bioavailability within the gastrointestinal (GI) tract. Over the years, probiotic-based peptide delivery vehicles comprising of lactic acid bacteria such as Lactococcus lactis has emerged as an interesting alternative due to its generally recognized as safe (GRAS) status, a fully sequenced genome, transient gut colonization time, and is an efficient cellular factory for heterologous protein production. However, its survivability through the GI tract is low, thus better delivery approaches are being explored to improve its bioavailability. In this study, we employ the incorporation of a double coated mucoadhesive film consisting of sodium alginate and Lycoat RS 720 film as the inner coat. The formulated film exhibits good mechanical properties of tensile strength and percent elongation for manipulation and handling with an entrapment yield of 93.14±2.74%. The formulated mucoadhesive film is subsequently loaded into gelatin capsules with an outer enteric Eudragit L100-55 coating capable of a pH-dependent breakdown above pH 5.5 to protect against gastric digestion. The final product and unprotected controls were subjected to in vitro simulated gastrointestinal digestions to assess its survivability. The product demonstrated enhanced protection with an increase of 69.22±0.67% (gastric) and 40.61±8.23% (intestinal) survivability compared to unprotected controls after 6 hours of sequential digestion. This translates to a 3.5 fold increase in overall survivability. Owing to this, the proposed oral delivery system has shown promising potential as a live gastrointestinal vaccine delivery host. Further studies involving in vivo gastrointestinal survivability and mice immunization tests are currently being carried out to assess the efficacy of this novel oral delivery system in comparison to parenteral routes.

Formulation and optimization of duloxetine hydrochloride buccal films: in vitro and in vivo evaluation

Duloxetine hydrochloride (DH) is a serotonin-norepinephrine reuptake inhibitor (SSNRI) indicated for the treatment of depression. Duloxetine suffers from reduced oral bioavailability (≈50%) due to hepatic metabolism. This study aims to develop DH buccoadhesive films to improve its bioavailability. DH buccoadhesive films were prepared adopting the solvent casting method using hydroxypropyl methylcellulose (HPMC) and polyvinyl alcohol (PVA). The prepared films were evaluated for weight uniformity, drug content, surface pH, swelling index, mucoadhesion strength and drug release percentages. Accelerated stability and bioavailability studies in healthy human volunteers were also performed for the selected films. Results of the evaluation tests showed that the optimum physicochemical characters were obtained by the films prepared with 2% HPMC using 10% propylene glycol (F2 films). Accelerated stability studies revealed that DH showed proved stability throughout the experiment time. DH bioavailability from F2 films was determined and compared with that of the marketed oral capsules (Cymbalta® 30 mg). The pharmacokinetic results showed that Cmax for F2 was higher than the market product. In addition, ANOVA analysis showed that a Tmax of F2 film was significantly lower, while, the AUC0-72 of F2 was significantly higher than that of Cymbalta capsules. The percentage relative bioavailability of DH from F2 was found to be 296.39%. Therefore, the prepared buccal films offer an alternative route for the administration of DH with the possibility of improving its bioavailability.