In vitro release of theophylline from cross-linked gelatin capsules

Influence of the quality of capsule shell on the non-invasive monitoring of medicines using Terizidone as an example

The aim of this study is to investigate the influence of hard capsule shells on the possibility of non-invasive monitoring and authentication of medicines presented in capsules dosage form. It is shown that the NIR measurements followed by the chemometric analysis, reflects all macro-components of the analyzed samples, which are the PVC blister, the capsule shell, and the capsule contents. The special variable selection procedure, based on the pure spectra of all components, makes it possible to develop a model that is insensitive to small variations of the capsule shell. The shrinkage of spectral region can greatly affect the results of the classification. Consequently, in case we are interested in the whole remedy, capsules with deviations in shell properties should be rejected as the substandard ones. If we are only interested in the quality of capsules' content, the developed model is effective and applicable in the routine testing. The final model helps to understand and demonstrate the reason for the rejection of substandard samples authentication. It also gives a practical signal to the manufacturer to pay attention to the quality of the capsule shells.

Challenges of Dissolution Methods Development for Soft Gelatin Capsules

Recently, the development of soft gelatin capsules (SGCs) dosage forms has attracted a great deal of interest in the oral delivery of poorly water-soluble drugs. This is attributed to the increased number of poorly soluble drugs in the pipeline, and hence the challenges of finding innovative ways of developing bioavailable and stable dosage forms. Encapsulation of these drugs into SGCs is one of the approaches that is utilized to deliver the active ingredients to the systemic circulation to overcome certain formulation hurdles. Once formulated, encapsulated drugs in the form of SGCs require suitable in vitro dissolution test methods to ensure drug product quality and performance. This review focuses on challenges facing dissolution test method development for SGCs. A brief discussion of the physicochemical and formulation factors that affect the dissolution properties of SGCs will be highlighted. Likewise, the influence of cross-linking of gelatin on the dissolution properties of SGCs will also be discussed.

Cross-linking of hard gelatin carbamazepine capsules: effect of dissolution conditions on in vitro drug release

The aim of this study was to determine if the use of both enzyme and surfactant in the dissolution medium changes the in vitro drug release from cross-linked hard gelatin capsules containing a water-insoluble drug. Hard gelatin capsules were cross-linked by a controlled exposure to formaldehyde resulting in different stressed capsules and carbamazepine (CBZ) was chosen as a drug model. In vitro dissolution studies were conducted using simulated gastric fluid (SGF) and simulated intestinal fluid (SIF) with enzymes. Sodium lauryl sulfate (SLS) was added in the dissolution medium at a concentration of 2% m/v both in SGF and SIF with pepsin and pancreatin, respectively. The percentage of CBZ dissolved was reduced by increasing the degree of gelatin cross-linking. For unstressed hard gelatin capsules, 36% of the CBZ was released after 1 h, lowering to 5% for highly stressed hard gelatin capsules in the SGF. A similar effect was observed with SIF. In the case of moderately stressed hard gelatin capsules, addition of enzyme in the dissolution medium enhanced the percentage of CBZ dissolved. The dissolution level increased from 12% to 39% in SGF with pepsin for hard gelatin capsules cross-linked with 1500 ppm formaldehyde. On the contrary, the use of enzyme in the dissolution medium did not increase the dissolution of CBZ from highly stressed hard gelatin capsules. Surprisingly, the addition of SLS in the medium did not allow the release of the CBZ both in SGF and in SIF. The results of this study demonstrate that the use of enzyme in the dissolution medium is justified for moderately cross-linked hard gelatin capsules. However, the action of a surfactant added in the medium containing enzyme remains unclear.