Fixed-duration multidrug therapy in multibacillary leprosy.

Six-hundred-fifty-seven active multibacillary (MB) leprosy patients were put on fixed-duration multidrug therapy (FD-MDT) between 1985 and 1992 (190 had had no and 235 had had previous treatment with dapsone) and were followed for 5 years after therapy. Two relapses occurred during year 5 of surveillance and both had received dapsone prior to chemotherapy, giving an overall relapse rate of 0.08/100 person-years (py). Excluding the two relapses, 99.4% of the MB patients converted to smear negativity at year 6 after a regular course of FD-MDT. The relapse rate for 35 MB patients with an initial bacterial index (BI) of > 4 with 5 years of surveillance was 0.24/100 py. Reactions occurred more frequently during the first 6 months of MDT, decreasing gradually thereafter, and reaching 0 in year 4 of surveillance. The deformity rate at intake was 22.7% and only 1.8% of MB patients developed new deformities or an increased grade in deformity during therapy.

Expanded solubility parameter approach. I: Naphthalene and benzoic acid in individual solvents.

An expanded solubility parameter system was tested in conjunction with the extended Hansen solubility approach and the UNIFAC method to calculate the solubilities of naphthalene and benzoic acid in polar and nonpolar solvents. The expanded parameter system is characterized by delta d for the dispersion force, delta p for dipolar forces, a basic or electron-donor parameter, delta b, and an acidic or electron-acceptor parameter delta a. The correlation between the calculated and observed solubilities of benzoic acid was increased by use of the four-parameter system. An indicator variable was required to bring the solubilities into line in strongly dipolar solvents such as N,N-dimethylformamide. For naphthalene, use of the four-parameter approach proved not to be an improvement over the three-parameter extended Hansen solubility approach. The UNIFAC method was not successful in calculating solubilities of benzoic acid in the 40 polar and nonpolar solvents. A triangular plot of the three Hansen parameters for benzoic acid, p-hydroxybenzoic acid, and methyl p-hydroxybenzoate illustrated the contributions of dispersion, dipolar, and Lewis acid-base (hydrogen bonding) interaction forces among the three benzoic acid compounds and the various classes of solvents. A multiple regression procedure for calculating the four partial solubility parameters of drug solutes was developed.

Expanded solubility parameter approach. II: p-Hydroxybenzoic acid and methyl p-hydroxybenzoate in individual solvents.

The recently introduced four-parameter extended Hansen approach was used to study the solubility of p-hydroxybenzoic acid and methyl p-hydroxybenzoate in 32 and 35 individual solvents, respectively. The results are compared with those for benzoic acid in 40 solvents. Seventeen of the thirty-two or 53% of the calculated solubilities of p-hydroxybenzoic acid were within the established solubility criterion (i.e., less than 30% error from the experimental value). Twenty-two of thirty-six or 61% of the calculated solubility values for methyl p-hydroxybenzoate met the solubility criterion. Experimental excess free energies of solution for p-hydroxybenzoic acid and methyl p-hydroxybenzoate were plotted against theoretical values using the expanded four-parameter solubility regression equations. From such results, adjustments may be made in the partial solubility parameters to bring the calculated solubilities in line with experimental results. Multiple regression analyses were used to estimate the total solubility parameter and the four partial solubility parameters of the two benzoic acid derivatives. Satisfactory results were obtained for methyl p-hydroxybenzoate, but poor agreement was found for p-hydroxybenzoic acid for the total parameter when compared with the Fedors group contribution method. Both the multiple regression and group contribution methods may yield inaccurate solubility parameters for relatively polar solid solutes. Factor analysis was used to test the adequacy of three- and four-parameter approaches in the evaluation of drug solubility. A principal factor method without iteration and orthogonal factor rotation were used to compare the two expanded solubility parameter approaches.(ABSTRACT TRUNCATED AT 250 WORDS)

Extended Hansen approach: calculating partial solubility parameters of solid solutes.

A multiple linear regression method, known as the extended Hansen solubility approach, was used to estimate the partial solubility parameters, delta d, delta p, and delta h for crystalline solutes. The method is useful, since organic compounds may decompose near their melting points, and it is not possible, to determine solubility parameters for these solid compounds by the methods used for liquid solvents. The method gives good partial and total solubility parameters for naphthalene; with related compounds, less satisfactory results were obtained. At least three conditions, pertaining to the regression equation and the solvent systems, must be met in order to obtain reasonable solute solubility parameters. In addition to providing partial solubility parameters, the regression equations afford a calculation of solute solubility in both polar and nonpolar solvents.

Extended Hansen solubility approach: naphthalene in individual solvents.

A multiple regression method using Hansen partial solubility parameters, delta D, delta p, and delta H, was used to reproduce the solubilities of naphthalene in pure polar and nonpolar solvents and to predict its solubility in untested solvents. The method, called the extended Hansen approach, was compared with the extended Hildebrand solubility approach and the universal-functional-group-activity-coefficient (UNIFAC) method. The Hildebrand regular solution theory was also used to calculate naphthalene solubility. Naphthalene, an aromatic molecule having no side chains or functional groups, is "well-behaved', i.e., its solubility in active solvents known to interact with drug molecules is fairly regular. Because of its simplicity, naphthalene is a suitable solute with which to initiate the difficult study of solubility phenomena. The three methods tested (Hildebrand regular solution theory was introduced only for comparison of solubilities in regular solution) yielded similar results, reproducing naphthalene solubilities within approximately 30% of literature values. In some cases, however, the error was considerably greater. The UNIFAC calculation is superior in that it requires only the solute's heat of fusion, the melting point, and a knowledge of chemical structures of solute and solvent. The extended Hansen and extended Hildebrand methods need experimental solubility data on which to carry out regression analysis. The extended Hansen approach was the method of second choice because of its adaptability to solutes and solvents from various classes. Sample calculations are included to illustrate methods of predicting solubilities in untested solvents at various temperatures. The UNIFAC method was successful in this regard.

[The new marriage law and planned birth].

PIP: The New Marriage Law was passed during the Fifth National People's Congress. It raised the minimum marriage age from 20 years for men and 18 years for women stipulated by the Old Marriage Law to 22 years for men and 20 years for women. It also differs from the Old Marriage Law in that it strengthens its encouragement of late marriage, late births and birth control, emphasizes that birth planning is the duty of both husband and wife, and prohibits marriage of collateral blood relations within 3 generations (the Old Marriage Law's standard was "to follow custom"). A third of the provisions of the New Marriage Law concern family planning, of which the first 3 clauses are the most important: 1) To set guidelines for the relationship between marriage and family: the New Marriage Law is concerned with not just the family, but also marriage and birth and expects all citizens to comply with and protect these standards. 2) To implement freedom in marriage--equality for men and women; to protect the rights of women, children, and the aged; to implement planned birth. 3) To prohibit any action that prevents freedom of marriage, such as marriage on a mercenary basis and to prohibit financial profit from marriages. Other clauses include: 1) direct blood relations and victims of leprosy or other diseases determined unmarriageable by the medical profession are prohibited from marriage; 2) after marriage registration and with the mutual agreement of both parties, either partner can become a member of the other's family; children can take either parent's surname; both partners have mutual rights of inheritance, as do parents and children. In Heilungjiang Province, data from September 1980 show that 87.5% of its fertile women used contraceptives. From January to September 1980 85.6% married late; the rate of applications for One Child Certificates was 80%. By 1979 the rate of natural population increase was 10.14/1000.^ieng