A Shirwaikar

Herbal excipients in novel drug delivery systems

The use of natural excipients to deliver the bioactive agents has been hampered by the synthetic materials. However advantages offered by these natural excipients are their being non-toxic, less expensive and freely available. The performance of the excipients partly determines the quality of the medicines. The traditional concept of the excipients as any component other than the active substance has undergone a substantial evolution from an inert and cheap vehicle to an essential constituent of the formulation. Excipients are any component other than the active substance(s) intentionally added to formulation of a dosage form. This article gives an overview of herbal excipients which are used in conventional dosage forms as well as novel drug delivery systems.

The gastroprotective activity of the ethanol extract of Ageratum conyzoides.

The ethanol extract of Ageratum conyzoides was evaluated for gastroprotection in rats using the Ibuprofen, ethanol and cold restraint stress ulcer models. Efficacy was assessed by determination of mean ulcer size, ulcer number and ulcer index. Oral administration of the ethanol extract at dose levels of 500 and 750 mg/kg significantly protected gastric lesions by 80.59 and 89.33%, respectively, as compared to Misoprostol (74.43%) in the Ibuprofen model; by 97.09 and 99.24%, respectively, in the cold stress model as compared to Famotidine (77.86 and 92.71%) and by 86.58 and 92.29%, respectively, in the alcohol model. The findings suggest that the significant gastroprotective activity could be mediated by its antioxidant activity, Ca(2+) channel blocking and antiserotogenic properties.

Wound healing studies of Aristolochia bracteolata Lam. with supportive action of antioxidant enzymes

Aristolochia bracteolata is a perennial herb, the leaves of which are used by the native tribals and villagers of the Chittoor District of Andhra Pradesh in India for the rapid healing of cuts and wounds. The ethanol extract of the shade-dried leaves of Aristolochia bracteolata Lam. was studied for its effect on wound healing in rats, using incision, excision and dead-space wound models, at two different dose levels of 400 and 800 mg/kg/body wt./day. The plant showed a definite, positive effect on wound healing, with a significant increase of the level of two powerful antioxidant enzymes, super oxide dismutase and catalase, in the granuloma tissue.

Simultaneous UV spectrophotometric estimation of ambroxol hydrochloride and levocetirizine dihydrochloride

A novel, simple, sensitive and rapid spectrophotometric method has been developed for simultaneous estimation of ambroxol hydrochloride and levocetirizine dihydrochloride. The method involved solving simultaneous equations based on measurement of absorbance at two wavelengths 242 nm and 231 nm, the γ max of ambroxol hydrochloride and levocetirizine dihydrochloride, respectively. Beers law was obeyed in the concentration range 10–50 μg/ml and 8–24 μg/ml for ambroxol hydrochloride and levocetirizine dihydrochloride respectively. Results of the method were validated statistically and by recovery studies.

Simultaneous Estimation of Esomeprazole and Domperidone by UV Spectrophotometric Method.

A novel, simple, sensitive and rapid spectrophotometric method has been developed for simultaneous estimation of esomeprazole and domperidone. The method involved solving simultaneous equations based on measurement of absorbance at two wavelengths, 301 nm and 284 nm, λ max of esomeprazole and domperidone respectively. Beers law was obeyed in the concentration range of 5-20 μg/ml and 8-30 μg/ml for esomeprazole and domperidone respectively. The method was found to be precise, accurate, and specific. The proposed method was successfully applied to estimation of esomeprazole and domperidone in combined solid dosage form.

Preparation of mucoadhesive microspheres for nasal delivery by spray drying

In this study the suitability of spray drying as a method for the formulation of mucoadhesive microspheres for nasal delivery was evaluated. The microspheres were produced from mucoadhesive polymers including chitosan salt, hydroxypropylmethylcellulose, hydroxypropylcellulose, sodium alginate and contained levocetirizine dihydrochloride as the model drug. The microspheres formed were evaluated for particle size distribution, drug loading, production yield, in vitro release characteristics and suitability for nasal drug delivery in terms of particle size and release properties. The conditions of the spray dryer were optimized for production yield and particle size.

Studies of disintegrant properties of seed mucilage of Ocimum gratissimum

Dispersible tablets of Metformin Hydrochloride were prepared using Ocimum gratissimum mucilage powder and Ocimum gratissimum seed powder as disintegrants. Specifications for herbal raw materials and finished products were set according to the Committee for Proprietary Medicinal Products. Several formulations were prepared and evaluated for physical parameters such as thickness, hardness, friability, weight variation, drug content, and disintegration time and drug dissolution. The formulations were prepared with different proportions of Ocimum gratissimum mucilage powder and Ocimum gratissimum seed powder. The formulated tablets had good appearance and better drug release properties as compared to the marketed conventional tablets. The study revealed that Ocimum gratissimum mucilage powder and Ocimum gratissimum seed powder were effective as disintegrants in low concentrations (5%). The study further revealed a poor relation between the swelling index and disintegrating efficiency. Mucilage extracted from Ocimum gratissimum seeds was subjected to toxicity studies for its safety and preformulation studies for its suitability as a disintegrating agent. The mucilage extracted is devoid of toxicity. Studies indicated that the extracted mucilage is a good pharmaceutical adjuvant, specifically a disintegrating agent.

Determination of ebastine in pharmaceutical formulations by HPLC.

A simple, precise and rapid RP-HPLC method was developed for the determination of ebastine in pharmaceutical formulations. The method was carried out on a Phenomenex RP-C18 column using a mixture of methanol and water (90:10) and detection was done at 262 nm. The linearity range was 5-100 μg/ml. The intra-day and inter-day precision were in the range of 0.22% to 0.49% and 0.24% to 0.73%, respectively.

Determination of racecadotril by HPLC in capsules

A simple, precise and rapid RP-HPLC method was developed for the determination of racecadotril in a pharmaceutical formulation using gemfibrozil as internal standard. Ratio of the peak area of analyte to internal standard was used for quantification. The chromatographic separation was carried out by using a Reverse Phase C18 column (BDS-Hypersil). The mobile phase consisting of a mixture of 20 mM phosphate buffer (pH 3.5) and acetonitrile in the ratio of (40:60) with detection at 230 nm at a flow rate of 1 ml/min was employed. The method was statistically validated for linearity, accuracy and precision. The elution time was 6.9 min for racecadotril and 9.8 min for gemfibrozil. The simplicity and accuracy of the proposed method ensures its use in routine quality control analysis of pharmaceutical formulations.

Treatment of onychomycosis: An update

Fungal infections of skin are one of the most common infections in human beings. The areas which are likely to get infected include the scalp, the hands and the feet. Dermatophytes, yeasts and moulds are the three major fungi responsible for skin infections. Earlier oral antifungal agents were used for treatment of fungal infection in finger and toe nails. The disadvantages of oral antifungal agents are toxicity and longer treatment period. Now medicated nail lacquers have been developed for the treatment of fungal infections i.e. onychomycosis, which has less toxicity and shorter treatment period.