Development of Rectodispersible Tablets and Granulate Capsules for the Treatment of Serious Neonatal Sepsis in Developing Countries

Current pediatric antibiotic therapies often use oral and parenteral routes of administration. Neither are suitable for treating very sick neonates who cannot take oral medication and may be several hours away from hospital in developing countries. Here, we report on the development of rectal forms of ceftriaxone, a third-generation cephalosporin. Rectodispersible tablets and capsules were developed and successfully passed 6-month accelerated stability tests. Rabbit bioavailability showed plasma concentrations above the minimal inhibitory concentrations for 3 formulations of rectodispersible tablets and 2 formulations of hard capsules. Clinical batches are currently being prepared for human evaluation with the prospect of offering therapeutic alternatives for treating critically ill neonates. This proof of concept for efficient rectal delivery of antibiotics could help the development of other rectal antibiotic treatments and increase options for noninvasive drug development for pediatric patients.

Freeze-Dried Matrices Based on Polyanion Polymers for Chlorhexidine Local Release in the Buccal and Vaginal Cavities

Chlorhexidine (CLX) is a wide spectrum cationic antimicrobial used for prevention and treatment of infections of buccal and vaginal cavities. To increase the residence time of CLX-based formulations at the application site and consequently reduce the daily dose frequency, new formulations composed of mucoadhesive polymers should be designed. The objective of this work was the development of matrices based on polyanionic polymers, such as sodium alginate, carboxymethylcellulose, xanthan gum and sodium hyaluronate, aimed to prolong the local release of CLX into the buccal or vaginal cavity. Matrices were prepared by freeze-drying and comply with 2 different preparative methods and characterized in terms of resistance to compression, water uptake ability, mucoadhesion, in vitro drug release behavior and antimicrobial activity toward representative pathogens of buccal and vaginal cavities. Results showed that the selection of suitable polymers associated to the adequate preparative method allowed to modulate matrix ability to hydrate, adhere to the mucosa and release the drug as well as to exert antimicrobial activity. In particular, matrix based on sodium hyaluronate was found to be the best performing formulation and could represent a versatile system for local release of CLX with potential application in both buccal and vaginal cavities.

Prediction of the Long-Term Dissolution Performance of an Immediate-Release Tablet Using Accelerated Stability Studies

A slowdown in dissolution performance has been observed for an immediate release tablet formulation during long-term stability testing. The slowdown was successfully predicted using an accelerated stability study in which the dissolution was tested over a range of temperatures, humidity conditions and storage times. The slowdown was quantified using a calculated parameter referred to as the "acceleration factor" (AF); this is the degree by which the timescale (x-axis) of a dissolution profile needs to be scaled to overlay it on to the dissolution profile obtained at the initial timepoint. The "AF" approach was applicable because it was observed that the shape of the dissolution profile remains consistent even though different dissolution rates were obtained. Under the accelerated stability conditions, the AF is observed to follow an "exponential decay" curve. A predictive model for the long-term stability dissolution was obtained by modeling both the plateau level and the rate constant for the exponential decay curve as functions of temperature and humidity. The long-term stability of product A in packaging was successfully predicted using this model in combination with simulations of the changing relative humidity conditions inside the packaging.

Enhancing the Dissolution Stability of Hard Gelatin Capsules Using Activated Carbon as a Packaging Component

Hard gelatin capsule (HGC) shells are widely used to encapsulate drugs for oral delivery but are vulnerable to gelatin cross-linking, which can lead to slower and more variable in vitro dissolution rates. Adding proteolytic enzymes to the dissolution medium can attenuate these problems, but this complicates dissolution testing and is only permitted by some regulatory authorities. Here, we expand the scope of our previous work to demonstrate that canisters containing activated carbon (AC) or polymeric films embedded with AC particles can be used as packaging components to attenuate gelatin cross-linking and improve the dissolution stability of hard gelatin-encapsulated products under accelerated International Council for Harmonisation conditions. We packaged acetaminophen and diphenhydramine HCl HGCs with or without AC canisters in induction-sealed high-density polyethylene bottles and with or without AC films in stoppered glass vials and stored these samples at 50°C/75% relative humidity through 3 months and at 40°C/75% relative humidity for 6 months. Samples packaged with AC canisters or AC films dissolved more rapidly than samples packaged without AC when differences were observed. These results demonstrate that different sources and formats of AC can enhance the dissolution stability of HGCs packaged in bottles and other potential packaging systems such as blister cards.

FIP Guidelines for Dissolution Testing of Solid Oral Products

Dissolution testing is an important physiochemical test for the development of solid oral dosage forms, tablets, and capsules. As a quality control test, the dissolution test is used for assessment of drug product quality and is specified for batch release and regulatory stability studies. In vitro dissolution test results can often be correlated with the biopharmaceutical behavior of a product.This article provides a summary of views from major global agencies (Europe, Japan, United States), pharmacopoeias, academia, and industry. Based on available guidance and literature, this article summarizes highlights for development and validation of a suitable dissolution method, setting appropriate specifications, in vitro-in vivo comparison, and how to obtain a biowaiver.

A Simulated Stomach Duodenum Model Predicting the Effect of Fluid Volume and Prandial Gastric Flow Patterns on Nifedipine Pharmacokinetics From Cosolvent-Based Capsules

Nifedipine is a Biopharmaceutics Classification System class II drug displaying large variability in absorption even when administered as immediate-release soft gelatin capsules of a cosolvent formulation. This in vitro study sought to understand the reasons behind variability in nifedipine absorption, how it can be minimized, and if it can be predicted using in vitro models. A dynamic in vitro simulated stomach duodenum model was used to explore drug concentration-time profiles of nifedipine soft gelatin capsules under conditions simulating how patients take their medicines. Specifically, the effect of prandial gastric emptying patterns and fluid volume administration (250 mL vs. 50 mL water) were investigated. Significant supersaturation of nifedipine was observed. While administration of large and small water volumes gave rise to a similar C_max and area under the curve (AUC_∞), the coefficient of variation in AUC was 4.8% and 49%, respectively, which can be attributed to differences in precipitation kinetics. Fasting and fed gastric emptying patterns also gave rise to a similar AUC; however, C_max was significantly lower in the fed state. These trends are consistent with previously published in vivo results in healthy volunteers. The simulated stomach duodenum provides a good discriminative screening tool for predicting trends in drug concentration profiles of Biopharmaceutics Classification System class II drugs.