Development of in vitro-in vivo correlation for extended-release niacin after administration of hypromellose-based matrix formulations to healthy volunteers.

Development of in vitro-in vivo correlations (IVIVCs) for extended-release (ER) products is commonly pursued during pharmaceutical development to increase product understanding, set release specifications, and support biowaivers. This manuscript details the development of Level C and Level A IVIVCs for ER formulations of niacin, a highly variable and extensively metabolized compound. Three ER formulations were screened in a cross-over study against immediate-release niacin.

Suitability of a minipig model in assessing clinical bioperformance of matrix and multiparticulate extended-release formulations for a BCS class III Drug development candidate.

Preclinical studies in dogs are often employed as part of formulation screening process. However, the shorter transit time and colonic length in dogs may result in underestimation of absorption, especially for extended-release (ER) formulations. In the recent years, minipigs have attracted attention as an alternative animal model.

A 1-step Bayesian predictive approach for evaluating in vitro in vivo correlation (IVIVC).

IVIVC (in vitro in vivo correlation) methods may support approving a change in formulation of a drug using only in vitro dissolution data without additional bioequivalence trials in human subjects. Most current IVIVC methods express the in vivo plasma concentration of a drug formulation as a function of the cumulative in vivo absorption. The absorption is not directly observable, so is estimated by the cumulative dissolution of the drug formulation in in vitro dissolution trials.

Modulation of drug release kinetics from hydroxypropyl methyl cellulose matrix tablets using polyvinyl pyrrolidone.

Hydrophilic matrix tablets are widely used to extend the release of a broad range of pharmaceutically active materials. The mechanism and kinetics of drug release are dependent on the solubility of the active moiety and the swelling and erosion properties of the polymer, with water soluble compounds released predominantly by diffusion. The swelling and erosion properties of hydroxypropyl methyl cellulose (HPMC), typically lead to a first order release rate for water soluble compounds as opposed to the more desirable zero-order kinetics.

The development of a stable, coated pellet formulation of a water-sensitive drug, a case study: development of a stable core formulation.

A development program has been carried out to provide a stable extrusion/spheronisation pellet formulation for a highly water-soluble drug, sitagliptin, which undergoes a change in physical form on processing and is subject to hydrolytic decomposition. A conventional extrusion/spheronization formulation resulted in significant degradation of the drug. The inclusion of glyceryl monostearate into the formulation was found to reduce the water levels required to such a level that there was no significant degradation of the drug during processing to form pellets.

Rational design of powder formulations for tamp filling processes.

Tamp filling processes are widely used for the filling of powders into hard gelatin capsules, whereby capsule fill weight is controlled by the formation of a loosely packed plug of material that is dispensed into the capsule shell. To rationally design formulations for tamp filling processes the formulator must have an intimate knowledge of the synergy between machine parameters and powder properties and the corresponding effect on product quality. However, despite ubiquitous use throughout the pharmaceutical industry, relatively little is understood about the design of powders for tamp filling processes.

Understanding the physical stability of freeze dried dosage forms from the glass transition temperature of the amorphous components.

Modulated differential scanning calorimetry has been applied to understanding the long-term physical stability of freeze-dried units. It is known that these units are liable to contract on exposure to elevated temperature or humidity. The contraction occurs when the storage temperature is above the glass transition temperature of the amorphous components in the system.

An investigation into the subambient behavior of aqueous mannitol solutions using differential scanning calorimetry, cold stage microscopy, and X-ray diffractometry.

The subambient behavior of aqueous mannitol solutions is of considerable relevance to the preparation of freeze dried formulations. In this investigation the properties of 3% w/v mannitol solutions were investigated using differential scanning calorimetry (DSC), cold stage microscopy (CSM), and X-ray diffraction (XRD) to identify the thermal transitions and structural transformations undergone by this system. It was found that on cooling from ambient the system formed ice at circa -20 degrees C while a further exotherm was seen at approximately -30 degrees C.

Further investigations into the use of high sensitivity differential scanning calorimetry as a means of predicting drug-excipient interactions.

The early prediction of drug-excipient incompatibility is vital in the pharmaceutical industry to avoid costly material wastage and time delays. We report here on the use of high sensitivity differential scanning calorimetry (HSDSC) to examine the compatibility between an experimental drug (Drug A) and common pharmaceutical excipients. Short-term HSDSC experiments (up to 25h) indicated that Drug A was stable in the presence of moisture and was compatible with both lactose monohydrate and magnesium stearate in the dry state, but showed degradation in the presence of magnesium stearate and water in combination.

Effect of moisture on polyvinylpyrrolidone in accelerated stability testing.

Accelerated stability studies are a common approach for predicting the long-term stability of pharmaceutical formulations. However, in this study, a slowing of dissolution was observed for a formulation following storage at elevated temperature and humidity. The moisture sorption isotherm for the binder, polyvinylpyrrolidone (PVP), shows absorption of a significant quantity of water on exposure to elevated humidity.