Release of 5-aminosalicylate from an MMX mesalamine tablet during transit through a simulated gastrointestinal tract system

5-Aminosalicylate (5-ASA; mesalamine) is the current first-line treatment for mild to moderate ulcerative colitis, a chronic inflammatory condition that most commonly affects the distal part of the colon. MMX™ mesalamine (Lialda™ [US]; Mezavant™ XL [UK and Ireland]; Mezavant™ [elsewhere]; Shire Pharmaceuticals Inc., Wayne, Pa, under license from Giuliani SpA, Milan, Italy) was created to be a novel, once-daily 5-ASA formulation. MMX mesalamine in tablet form has a pH-dependent, gastroresistant coating and is designed to delay the release of 5-ASA during transit through the upper gastrointestinal tract; it consists of hydrophilic and lipophilic excipients that are designed to prolong the release of 5-ASA throughout the colon. The release kinetics of 5-ASA from an MMX mesalamine tablet were assessed with the use of a dynamic in vitro gastroin-testinal tract system (TNO GastroIntestinal Model) that simulates physiologic conditions in the adult human gastrointestinal tract under standardized fed and fasted conditions. This system incorporates removal of released drug via dialysis and automated sampling taken at various sections of the system. Less than 1 % of 5-ASA was found to be released from the tablet in the simulated stomach and small intestine (before introduction into the simulated colon). Most of the 5-ASA within each tablet was released in the simulated colon (fasted state conditions: 78.0%; fed state conditions: 68.5%). Substantial quantities were released during the 8- to 18-hour sampling period (49.6 mg/h [fasted] and 40.7 mg/h [fed]). In conclusion, with the use of an in vitro system, the investigators showed that 5-ASA release from an MMX mesalamine tablet was delayed until the tablet reached the simulated colon. Throughout the simulated colon, release of 5-ASA from an MMX mesalamine tablet was prolonged. ©2007 Health Communications Inc

Development and Evaluation of Lorazepam Microemulsions for Parenteral Delivery

The objective of this investigation was to develop lorazepam (LZM) microemulsions as an alternative to the conventional cosolvent based formulation. Solubility of LZM in various oils and Tween 80 was determined. The ternary diagram was plotted to identify area of microemulsion existence and a suitable composition was identified to achieve desired LZM concentration. The LZM microemulsions were evaluated for compatibility with parenteral fluids, globule size, in vitro hemolysis and stability of LZM. Capmul MCM demonstrated highest solubilizing potential for LZM and was used as an oily phase. LZM microemulsions were compatible with parenteral dilution fluids and exhibited mean globule size less than 200 nm. The in vitro hemolysis studies indicated that microemulsions were well tolerated by erythrocytes. The LZM microemulsions containing amino acids exhibited good physical and chemical stability when subjected to refrigeration for 6 months

Microemulsion-Based Vaginal Gel of Clotrimazole: Formulation, In Vitro Evaluation, and Stability Studies

The objective of the present investigation was to develop and evaluate microemulsion-based gel for the vaginal delivery of clotrimazole (CMZ). The solubility of CMZ in oils and surfactants was evaluated to identify components of the microemulsion. The ternary diagram was plotted to identify the area of microemulsion existence. Various gelling agents were evaluated for their potential to gel the CMZ microemulsion without affecting its structure. The bioadhesive potential and antifungal activity of the CMZ microemulsion-based gel (CMZ-MBG) was determined in comparison to the marketed clotrimazole gel (Candid-V® gel) by in vitro methods. The chemical stability of CMZ in CMZ-MBG was determined as per the International Conference on Harmonization guidelines. The CMZ microemulsion exhibited globule size of 48.4 nm and polydispersity index of 0.75. Carbopol® ETD 2020 could successfully gel the CMZ microemulsion without disturbing the structure. The CMZ-MBG showed significantly higher (P < 0.05) in vitro bioadhesion and antifungal activity as compared to that of Candid-V® gel. The stability studies indicated that CMZ undergoes acidic pH-catalyzed degradation at all the storage conditions at the end of 3 months

The prevalence of beta-haemolytic streptococci in throat specimens from healthy children and adults. Implications for the clinical value of throat cultures

Objective - To examine the influence of age and season of the year on the carrier rate of beta-haemolytic streptococci (BHS) in healthy individuals and patients with throat pain.\ud \ud Design - The prevalence of BHS in throat specimens from healthy individuals was compared with that from patients with throat pain of the same age in a defined geographical area, collected during the same mid-winter and late summer periods.\ud \ud Results -The prevalence of BHS in healthy individuals was low before the age of 3 years (1.9-7.1%) and in adults 216 years (2.4-3.7%) and highest in the age group 3-15 years (5.0-21.2%). The difference in prevalence of BHS between healthy individuals and patients with throat pain was small during the late\ud summer season and large during the mid-winter season.\ud \ud Conclusion - Prevalence of BHS varies with age and season in healthy individuals and patients with throat pain. During the summer, it is much more difficult to interpret the result of a throat culture in individuals aged < l6 years