Influence of process and formulation parameters on dissolution and stability characteristics of Kollidon® VA 64 hot-melt extrudates.

The objective of the present study was to investigate the effects of processing variables and formulation factors on the characteristics of hot-melt extrudates containing a copolymer (Kollidon® VA 64). Nifedipine was used as a model drug in all of the extrudates. Differential scanning calorimetry (DSC) was utilized on the physical mixtures and melts of varying drug-polymer concentrations to study their miscibility. The drug-polymer binary mixtures were studied for powder flow, drug release, and physical and chemical stabilities. The effects of moisture absorption on the content uniformity of the extrudates were also studied. Processing the materials at lower barrel temperatures (115-135°C) and higher screw speeds (50-100 rpm) exhibited higher post-processing drug content (~99-100%). DSC and X-ray diffraction studies confirmed that melt extrusion of drug-polymer mixtures led to the formation of solid dispersions. Interestingly, the extrusion process also enhanced the powder flow characteristics, which occurred irrespective of the drug load (up to 40% w/w). Moreover, the content uniformity of the extrudates, unlike the physical mixtures, was not sensitive to the amount of moisture absorbed. The extrusion conditions did not influence drug release from the extrudates; however, release was greatly affected by the drug loading. Additionally, the drug release from the physical mixture of nifedipine-Kollidon® VA 64 was significantly different when compared to the corresponding extrudates (f2 = 36.70). The extrudates exhibited both physical and chemical stabilities throughout the period of study. Overall, hot-melt extrusion technology in combination with Kollidon® VA 64 produced extrudates capable of higher drug loading, with enhanced flow characteristics, and excellent stability.

Formulation optimization of hot-melt extruded abuse deterrent pellet dosage form utilizing design of experiments.

OBJECTIVE: The objective of this study was to develop techniques for an abuse-deterrent (AD) platform utilizing the hot-melt extrusion (HME) process. METHODS: Formulation optimization was accomplished by utilizing Box-Behnken design of experiments to determine the effect of the three formulation factors: PolyOx WSR301, Benecel K15M and Carbopol 71G; each of which was studied at three levels on tamper-resistant (TR) attributes of the produced melt extruded pellets. A response surface methodology was utilized to identify the optimized formulation. Lidocaine hydrochloride was used as a model drug, and suitable formulation ingredients were employed as carrier matrices and processing aids. KEY FINDINGS: All of the formulations were evaluated for the TR attributes, such as particle size post-milling, gelling and percentage of drug extraction in water and alcohol. All of the design of experiments formulations demonstrated sufficient hardness and elasticity, and could not be reduced into fine particles (<150 µm), which is a desirable feature to prevent snorting. In addition, all of the formulations exhibited good gelling tendency in water with minimal extraction of drug in the aqueous medium. Moreover, Benecel K15M, in combination with PolyOx WSR301, could be utilized to produce pellets with TR potential. CONCLUSION: HME has been demonstrated to be a viable technique with a potential to develop novel AD formulations.

Oral transmucosal delivery of domperidone from immediate release films produced via hot-melt extrusion technology.

The objective of the study was to prepare and characterize the domperidone (DOM) hot-melt extruded (HME) buccal films by both in vitro and in vivo techniques. The HME film formulations contained PEO N10 and/or its combination with HPMC E5 LV or Eudragit RL100 as polymeric carriers, and PEG3350 as a plasticizer. The blends were co-processed at a screw speed of 50 rpm with the barrel temperatures ranging from 120-160°C utilizing a bench top co-rotating twin-screw hot-melt extruder using a transverse-slit die. The HME films were evaluated for drug content, drug excipient interaction, in vitro drug release, mechanical properties, in vivo residence time, in vitro bioadhesion, swelling and erosion, ex vivo permeation from HME films and the selected optimal formulation was subjected for bioavailability studies in healthy human volunteers. The extruded films demonstrated no drug excipient interaction and excellent content uniformity. The selected HME film formulation (DOM2) exhibited a tensile strength (0.72 Kg/mm(2)), elongation at break (28.4% mm(2)), in vivo residence time (120 min), peak detachment force (1.55 N), work of adhesion (1.49 mJ), swelling index (210.2%), erosion (10.5%) and in vitro drug release of 84.8% in 2 h. Bioavailability from the optimized HME buccal films was 1.5 times higher than the oral dosage form and the results showed statistically significant (p < 0.05) difference. The ex vivo-in vivo correlation was found to have biphasic pattern and followed type A correlation. The results indicate that HME is a viable technique for the preparation of DOM buccal-adhesive films with improved bioavailability characteristics.

Melt extrusion with poorly soluble drugs.

Melt extrusion (ME) over recent years has found widespread application as a viable drug delivery option in the drug development process. ME applications include taste masking, solid-state stability enhancement, sustained drug release and solubility enhancement. While ME can result in amorphous or crystalline solid dispersions depending upon several factors, solubility enhancement applications are centered around generating amorphous dispersions, primarily because of the free energy benefits they offer. In line with the purview of the current issue, this review assesses the utility of ME as a means of enhancing solubility of poorly soluble drugs/chemicals. The review describes major processing aspects of ME technology, definition and understanding of the amorphous state, manufacturability, analytical characterization and biopharmaceutical performance testing to better understand the strength and weakness of this formulation strategy for poorly soluble drugs. In addition, this paper highlights the potential advantages of employing a fusion of techniques, including pharmaceutical co-crystals and spray drying/solvent evaporation, facilitating the design of formulations of API exhibiting specific physico-chemical characteristics. Finally, the review presents some successful case studies of commercialized ME based products.

Melt extrusion: process to product.

INTRODUCTION: Niche applicability and industrial adaptability have led hot melt extrusion (HME) techniques to gain wide acceptance and have, therefore, solidified their place in the array of pharmaceutical research and manufacturing operations. Melt extrusion's momentum has resulted in extensive research publications, reviews and patents on the subject for over a decade. Currently, > 50% of the new drug candidates are speculated to be highly lipophilic and thus poorly bioavailable. HME is a key technology for these and other formulation and processing issues. AREAS COVERED: Various approaches have been addressed using HME in developing solid molecular dispersions and have demonstrated viability to provide sustained, modified and targeted drug delivery resulting in improved bioavailability. This review provides a holistic perspective on HME from equipment, processing and materials to its varied applications in oral delivery (immediate release, sustained release, taste masking, enteric and targeted release, as well as trans-drug delivery), oral mucosal, dermal, ungual and intravaginal systems. EXPERT OPINION: Interest in HME as a pharmaceutical process continues to grow and the potential of automation and reduction of capital investment and labor costs has earned this technique a necessary consideration as a drug delivery solution.

Physicochemical characterization of berberine chloride: a perspective in the development of a solution dosage form for oral delivery.

The objective of the present research was to evaluate the physicochemical characteristics of berberine chloride and to assess the complexation of drug with 2-hydroxypropyl-ß-cyclodextrin (HPßCD), a first step towards solution dosage form development. The parameters such as log P value were determined experimentally and compared with predicted values. The pH-dependent aqueous solubility and stability were investigated following standard protocols at 25°C and 37°C. Drug solubility enhancement was attempted utilizing both surfactants and cyclodextrins (CDs), and the drug/CD complexation was studied employing various techniques such as differential scanning calorimetry, Fourier transform infrared, nuclear magnetic resonance, and scanning electron microscopy. The experimental log P value suggested that the compound is fairly hydrophilic. Berberine chloride was found to be very stable up to 6 months at all pH and temperature conditions tested. Aqueous solubility of the drug was temperature dependent and exhibited highest solubility of 4.05 ± 0.09 mM in phosphate buffer (pH 7.0) at 25°C, demonstrating the effect of buffer salts on drug solubility. Decreased drug solubility was observed with increasing concentrations of ionic surfactants such as sodium lauryl sulfate and cetyl trimethyl ammonium bromide. Phase solubility studies demonstrated the formation of berberine chloride-HPßCD inclusion complex with 1:1 stoichiometry, and the aqueous solubility of the drug improved almost 4.5-fold in the presence of 20% HPßCD. The complexation efficiency values indicated that the drug has at least threefold greater affinity for hydroxypropyl-ß-CD compared to randomly methylated-ß-CD. The characterization techniques confirmed inclusion complex formation between berberine chloride and HPßCD and demonstrated the feasibility of developing an oral solution dosage form of the drug.